What is monounsaturated fat

Monounsaturated fats have a single carbon-to-carbon double bond. The result is that it has two fewer hydrogen atoms than a saturated fat and a bend at the double bond. This structure keeps monounsaturated fats liquid at room temperature. Eating food that has more monounsaturated fat (or “healthy fat”) instead of saturated fat (like butter) may help lower cholesterol and reduce heart disease risk. Research also shows that monounsaturated fats may benefit insulin levels and blood sugar control, which can be especially helpful if you have type 2 diabetes. However, monounsaturated fat has the same number of calories (9 calories or 37kJ) as other types of fat and may contribute to weight gain if you eat too much of it. Good sources of monounsaturated fats are olive oil, peanut oil, canola oil, avocados, most nuts, as well as high-oleic safflower and sunflower oils. The carbon-carbon double bond found in monounsaturated or polyunsaturated fatty acids can exist in the cis or trans configuration. When the two hydrogen atoms are on opposite sides of the double bond, the configuration is called trans. When the hydrogen atoms are on the same side of the double bond, the configuration is called cis. Monounsaturated fats (monounsaturated fatty acids) are found in high concentrations in olive oil, peanut oil, canola, avocados, almonds, safflower oils, hazelnuts, pecans, pumpkin seeds and sesame seeds and most nuts. Monounsaturated fats also are part of most animal fats such as fats from chicken, pork, beef, and wild game. When you dip your bread in olive oil at an Italian restaurant, you’re getting mostly monounsaturated fat.

The most common cis-configured monounsaturated fats (monounsaturated fatty acids or MUFAs) in daily nutrition is oleic acid (18:1 n-9), followed by palmitoleic acid (16:1 n-7), and vaccenic acid (18:1 n-7). Moreover, oleic acid represents the topmost monounsaturated fats (monounsaturated fatty acids or MUFAs) provided in the diet (~90% of all MUFAs) ¹. The major trans-configured monounsaturated fats (monounsaturated fatty acids or MUFAs) is elaidic acid (trans 18:1 n-9). Some MUFA—such as mystrioleic (14:1 n-5), gondoic (20:1 n-9), erucic (22:1 n-9) and nervonic (24:1 n-9) acid—are synthesized in minor concentrations endogenously using other monounsaturated fats (monounsaturated fatty acids or MUFAs) as precursors ².

Key facts

• There is convincing evidence that replacing carbohydrates with monounsaturated fats (monounsaturated fatty acids or MUFA) increases HDL “good” cholesterol concentrations.
• There is convincing evidence that replacing saturated fats (C12:0–C16:0) with monounsaturated fats reduces LDL “bad” cholesterol concentration and total/HDL cholesterol ratio.
• There is possible evidence that replacing carbohydrates with monounsaturated fats improves insulin sensitivity.
• There is insufficient evidence for establishing a relationship between monounsaturated fats consumption and chronic disease end points such as coronary heart disease or cancer.
• There is insufficient evidence for establishing a relationship between monounsaturated fats consumption and body weight and percent adiposity.
• There is insufficient evidence for establishing a relationship between monounsaturated fats intake and risk of diabetes.

Figure 1. Monounsaturated Fat Structure

Figure 2. Saturated Fat Structure

Table 1. Selected monounsaturated fatty acids

The discovery that monounsaturated fat could be healthful came from the Seven Countries Study during the 1960s. It revealed that people in Greece and other parts of the Mediterranean region enjoyed a low rate of heart disease despite a high-fat diet. The main fat in their diet, though, was not the saturated animal fat common in countries with higher rates of heart disease. It was olive oil, which contains mainly monounsaturated fat. This finding produced a surge of interest in olive oil and the “Mediterranean Diet” a style of eating regarded as a healthful choice today.

Although there’s no recommended daily intake of monounsaturated fats, the Institute of Medicine recommends using them as much as possible along with polyunsaturated fats to replace saturated and trans fats.

For good health, the American Heart Association recommends the majority of the fats that you eat should be monounsaturated or polyunsaturated. Eat foods containing monounsaturated fats and/or polyunsaturated fats instead of foods that contain saturated fats and/or trans fats.

Fats can also have different effects on the cholesterol levels in your body. The bad fats, saturated fats and trans fats raise bad cholesterol (LDL) levels in your blood. Monounsaturated fats and polyunsaturated fats can lower bad cholesterol levels and are beneficial when consumed as part of a healthy dietary pattern. Modifying fat in your food (replacing some saturated (animal) fats with plant oils and unsaturated spreads) may reduce risk of heart and vascular disease, but it is not clear whether monounsaturated or polyunsaturated fats are more beneficial ³. 

Eating foods with fat is definitely part of a healthy diet. Just remember to choose foods that provide good fats (monounsaturated and polyunsaturated fats) and balance the amount of calories you eat from all foods with the amount of calories you burn. Aim to eat a dietary pattern that emphasizes intake of vegetables, fruits, and whole grains; includes low-fat dairy products, poultry, fish, legumes, non-tropical vegetable oils and nuts; and limits intake of sodium, sweets, sugar sweetened beverages and red meats. Doing so means that your diet will be low in both saturated fats and trans fats.

What are the types of fat?

There are 4 main types of fats:

1. Unsaturated fats are those that are liquid at room temperature. The two kinds of unsaturated fats are monounsaturated fat and polyunsaturated fat. Both of these unsaturated fats are typically liquid at room temperature. Unsaturated fats are in fish, such as salmon, trout and herring, and plant-based foods such as avocados, olives and walnuts. Liquid vegetable oils, such as soybean oil, corn oil, safflower oil, canola oil, olive oil, peanut oil, canola oil and sunflower oil, also contain unsaturated fats. Eaten in moderation, both kinds of unsaturated fats may help improve your blood cholesterol when used in place of saturated and trans fats. You want to include as many unsaturated fats in your diet because they can decrease bad cholesterol, contain high amounts of antioxidants such as Vitamin E, and contain essential omega-3 and omega-6 fatty acids. Unsaturated fats are typically classified by how many hydrogen bonds they have in their structure: either 1 (mono) or two or more (poly).
2. Monounsaturated fats. Monounsaturated fat is a type of unsaturated fat. Monounsaturated fats are liquid at room temperature but start to harden when chilled. Monounsaturated fats is one of the healthy fats, along with polyunsaturated fat. Monounsaturated fats are good for your health in several ways:
   • Monounsaturated fats can help lower your LDL (bad) cholesterol level. Cholesterol is a soft, waxy substance that can cause clogged, or blocked, arteries (blood vessels). Keeping your LDL level low reduces your risk for heart disease and stroke.
   • Eating plant foods high in monounsaturated fats, particularly extra virgin olive oil and tree nuts, may benefit heart health and blood sugar regulation. Monounsaturated fats from plants may lower bad cholesterol and raise good cholesterol. They also may improve the control of blood sugar levels. Replacing saturated fats with monounsaturated fats in your diet may lower the level of bad cholesterol and triglycerides in your blood. Triglycerides are fat cells that circulate in the bloodstream and are stored in the body’s fat cells. A high level of triglycerides in the blood increases the risk of diseases of the heart and blood vessels.
   • Monounsaturated fats help develop and maintain your cells.
   • Monounsaturated fats are found in plant foods, such as nuts, avocados, and vegetable oils. Monounsaturated fats are found in red meats and dairy products. About half the fats in these foods are saturated and half monounsaturated. Many plants and plant oils are high in monounsaturated fats but low in saturated fats. These include:
     • Oils from olives, peanuts, canola seeds, safflower seeds, and sunflower seeds.
     • Avocadoes.
     • Pumpkin seeds.
     • Sesame seeds.
     • Almonds.
     • Cashews.
     • Peanuts and peanut butter.
     • Pecans.
3. Polyunsaturated fats. Polyunsaturated fat is a type of unsaturated fat. Polyunsaturated fats are liquid at room temperature but start to harden when chilled. Polyunsaturated fats include omega-3 and omega-6 fats. These are essential fatty acids that your body needs for brain function and cell growth. Your body does not make essential fatty acids, so you must get them from food. Polyunsaturated fats can help lower your LDL (bad) cholesterol. Cholesterol is a soft, waxy substance that can cause clogged or blocked arteries (blood vessels). Having low LDL cholesterol reduces your risk for heart disease. Polyunsaturated fats is one of the healthy fats, along with monunsaturated fat. Polyunsaturated fat is found in plant and animal foods, such as salmon, vegetable oils, and some nuts and seeds.
   1. Omega-3 fatty acids are good for your heart in several ways. They help:
      • Reduce triglycerides, a type of fat in your blood
      • Reduce the risk of developing an irregular heartbeat (arrhythmia)
      • Slow the buildup of plaque, a substance comprising fat, cholesterol, and calcium, which can harden and clog your arteries
      • Slightly lower your blood pressure
   2. Sources of omega-3 fatty acids include:
      • Fish such as salmon, anchovies, mackerel, herring, sardines and tuna.
      • Oils from canola seeds, soybeans, walnuts and flaxseed.
      • Soybeans.
      • Chia seeds.
      • Flaxseed.
      • Walnuts.
   3. Omega-6 fatty acids may help:
      • Control your blood sugar
      • Reduce your risk for diabetes
      • Lower your blood pressure
   4. Sources of omega-6 fatty acids include:
      • Corn oil.
      • Cottonseed oil.
      • Peanut oil.
      • Soybean oil.
      • Sunflower oil.
4. Saturated fats. Saturated fats are those that are solid at room temperature. Examples include margarine, butter, whole fat dairy products, the fat marbling in meats, and coconut oil. Saturated fats don’t need to be avoided entirely, but diets high in saturated fats can increase bad cholesterol and triglycerides, increasing the risk for heart disease. The Dietary Guidelines for Americans suggest that less than 10% of calories a day should be from saturated fats. The American Heart Association recommends that saturated fats only make up 5 to 6% of your daily calories. For a 2,000 calorie diet, that is a total of 100 calories, or 11 grams a day. Foods high in saturated fats include:
   • Foods baked or fried using saturated fats.
   • Meats, including beef, lamb, pork as well as poultry, especially with skin.
   • Lard.
   • Dairy products like butter and cream.
   • Whole or 2% milk.
   • Whole-milk cheese or yogurt.
   • Oils from coconuts, palm fruits, or palm kernels.
5. Trans fats. Trans fatty acids are unhealthy fats that form when vegetable oil goes through a process called hydrogenation. This leads the fat to harden and become solid at room temperature. Hydrogenated fats, partially hydrogenated oils (PHOs) or “trans fats,” are often used to keep some foods fresh for a long time. Trans fats are unsaturated fats that are artificially turned into saturated fats and increase heart disease and stroke risk by raising bad LDL cholesterol and decreasing good HDL cholesterol levels. High LDL (bad) cholesterol along with low HDL (good) cholesterol levels can cause cholesterol to build up in your arteries (blood vessels). This increases your risk for heart disease and stroke. Trans fats have also been known to increase the risk of developing type 2 diabetes. Trans fats are most commonly found in fried foods, frozen baked products such as pizza, non-dairy coffee creamers, vegetable shortenings, some margarines, crackers, cookies, snack foods, and other foods made with or fried in partially hydrogenated oils (PHOs). Because of the health risks from trans fats, the United States Food and Drug Administration (FDA) has banned food manufacturers from adding partially hydrogenated oils (PHOs) to foods. Although the food industry has greatly reduced the use of trans fat in recent years, trans fat may still be found in many fried, packaged, or processed foods. There are very small amounts of naturally occurring trans fat in meats and dairy from grazing animals, such as cows, sheep and goats. You should avoid foods made with hydrogenated and partially hydrogenated oils (such as hard butter and margarine). They may contain high levels of trans fatty acids. It is important to read nutrition labels on foods. This will help you know what kinds of fats, and how much, your food contains.

Cutting down on foods and drinks that are high in saturated and trans fats will help to keep your heart healthy and maintain your weight. You can replace some of them with unsaturated fats.

Recommendations for fat intake

Because some dietary fats are potentially helpful and others potentially harmful to your health, it pays to know which ones you’re eating and whether you’re meeting recommendations.

The Dietary Guidelines for Americans offers the following recommendations about dietary fat intake ⁴:

• Avoid trans fat.
• Limit saturated fat to less than 10 percent of calories a day.
• Replace saturated fat with healthier monounsaturated and polyunsaturated fats.

Be aware that many foods contain different kinds of fat and varying levels of each type. For example, butter contains unsaturated fats, but a large percentage of the total fat is saturated fat. And canola oil has a high percentage of monounsaturated fat but also contains smaller amounts of polyunsaturated and saturated fat.

Your body needs some fat — the healthy fats — to function normally. If you try to avoid all fat, you risk getting insufficient amounts of fat-soluble vitamins and essential fatty acids.

The most common monounsaturated fats (monounsaturated fatty acids or MUFA) in daily nutrition is oleic acid, followed by palmitoleic acid, and vaccenic acid ⁵. Moreover, oleic acid represents the topmost monounsaturated fats (monounsaturated fatty acids or MUFA) provided in the diet (~90% of all MUFA) ⁵. No dietary recommendations for monounsaturated fats are given by the National Institute of Medicine, the United States Department of Agriculture, the European Food and Safety Authority and the American Diabetes Association. In contrast, the Academy of Nutrition and Dietetics as well as the Canadian Dietetic Association both promote <20% monounsaturated fats of daily total energy consumption, while the American Heart Association sets a limit of 20% monounsaturated fats in their respective guidelines ², ⁶.
Figure 3. Dietary Fats and Mortality Rates

Examples of foods high in monounsaturated fats include plant-based liquid oils such as:

• olive oil,
• canola oil,
• peanut oil,
• safflower oil and
• sesame oil.

Other sources include avocados, peanut butter, and many nuts and seeds.

There are nine calories (37kJ) in every gram of fat, regardless of what type of fat it is. Fats are more energy-dense than carbohydrates and proteins, which provide four calories per gram.

Consuming high levels of calories – regardless of the source – can lead to weight gain or being overweight. Consuming high levels of saturated or trans fats can also lead to heart disease and stroke. Health experts generally recommend replacing saturated fats and trans fats with monounsaturated fats and polyunsaturated fats – while still maintaining a nutritionally-adequate diet.

Also, in attempting to remove fat from your diet, you may wind up eating too many processed foods touted as low-fat or fat-free rather than healthier and naturally lower fat foods, such as fruits, vegetables, legumes and whole grains. Instead of doing away with fat in your diet, enjoy healthy fats in moderation.

Why we need some fat?

A small amount of fat is an essential part of a healthy, balanced diet. Fat is a source of essential fatty acids, which the body can’t make itself.

Fat helps the body absorb vitamins A, D, K and E. These vitamins are fat-soluble, meaning they can only be absorbed with the help of fats.

Any fat not used by your body’s cells or to create energy is converted into body fat. Likewise, unused carbohydrate and protein are also converted into body fat.

All types of fat are high in energy. A gram of fat, whether saturated or unsaturated, provides 9kcal (37kJ) of energy compared with 4kcal (17kJ) for carbohydrate and protein.

The main types of fat found in food are:

• saturated fats
• unsaturated fats

Most fats and oils contain both saturated and unsaturated fats in different proportions.

As part of a healthy diet, you should try to cut down on foods and drinks high in saturated fats and trans fats, and replace some of them with unsaturated fats.

Summary of dietary fat

Different types of dietary fat had different associations with mortality, the researchers found. Trans fats—on their way to being largely phased out of food—had the most significant adverse impact on health. Every 2% higher intake of trans fat was associated with a 16% higher chance of premature death during the study period. Higher consumption of saturated fats was also linked with greater mortality risk. When compared with the same number of calories from carbohydrate, every 5% increase in saturated fat intake was associated with an 8% higher risk of overall mortality.

Conversely, intake of high amounts of unsaturated fats—both polyunsaturated and monounsaturated—was associated with between 11% and 19% lower overall mortality compared with the same number of calories from carbohydrates. Among the polyunsaturated fats, both omega-6, found in most plant oils, and omega-3 fatty acids, found in fish and soy and canola oils, were associated with lower risk of premature death.

Because fat is an essential nutrient to give your body energy, help your body absorb some nutrients and produce important hormones and to support cell growth. Eating foods with fat is definitely part of a healthy diet. A healthy diet can include the foods you love. You don’t have to avoid treats entirely, but you do need to eat less of foods that are low in nutrition and high in calories.

Just remember to choose foods that provide good fats (monounsaturated and polyunsaturated fats) and balance the amount of calories you eat from all foods with the amount of calories you burn. Whether it is olive oil, ghee, butter or coconut oil — they are all 100 percent fat. All fat have calories.

All fats, whether good or bad, no matter how good the oil sounds — remember that it is still a fat, with 120 calories per tablespoon. Consuming a high fat diet may lead to becoming overweight and that is not healthy !

Aim to eat a dietary pattern that emphasizes intake of vegetables, fruits, and whole grains; includes low-fat dairy products, poultry, fish, legumes, non-tropical vegetable oils and nuts; and limits intake of sodium, sweets, sugar sweetened beverages and red meats. Doing so means that your diet will be low in both saturated fats and trans fats.

While you switch to a heart-healthy diet you may need to keep tabs on your calorie intake for a while.

Polyunsaturated fat vs Monounsaturated fat

Polyunsaturated fats (polyunsaturated fatty acids or PUFAs) have two or more carbon-to-carbon double bond. The result is that it has two fewer hydrogen atoms than a saturated fat and a bend at the double bond. This structure keeps polyunsaturated fats liquid at room temperature.Polyunsaturated fatty acids (PUFAs) are found in high concentrations in sunflower, corn, soybean, flaxseed oils, walnuts, flax seeds, hemp seeds, pine nuts, sesame, cottonseed oils, pumpkin seeds and fish.

Polyunsaturated fatty acids (PUFAs) can be further subdivided on the basis of the location of the first carbon-to-carbon double bond relative to the methyl terminus of the chain. For example, Omega-3 and Omega-6 fatty acids are two of the most biologically significant polyunsaturated fatty acid classes, and have their first carbon-to-carbon double bond on either the third or sixth carbon from the chain terminus, respectively. The final carbon in the fatty acid chain is also known as the omega carbon, hence the common reference to these fatty acids as omega-3 or omega-6 PUFAs. The distinction between omega-6 and omega-3 fatty acids is based on the location of the first carbon-to-carbon double bond, counting from the methyl end of the fatty acid molecule (see Figure 5). Omega-6 fatty acids are represented by Linoleic acid (LA) (18:2ω-6) and Arachidonic acid (AA) (20:4ω-6) and Omega-3 fatty acids by Alpha-linolenic acid (ALA) (18:3ω-3), Eicosapentaenoic acid (EPA) (20:5ω-3) and Docosahexaenoic acid (DHA) (22:6ω-3).

Long-chain Omega-3 and Omega-6 PUFAs are synthesized from the essential fatty acids: alpha-linolenic acid (ALA) and linoleic acid (LA), respectively. Basic structures of these two parent PUFAs are shown in Figure 4 and Figure 5. An essential fatty acid cannot be made by your body and must be obtained through dietary sources. Animals and humans have the capacity to breakdown essential fatty acids to long-chain derivatives. Because the Omega-6 and Omega-3 pathways compete with one another for enzyme activity, the ratio of Omega-6 to Omega-3 PUFAs is very important to human health. An overabundance of fatty acids from one family will limit the metabolic production of the longer chain products of the other. The typical Western diet provides Omega-6 and Omega-3 PUFAs in a ratio ranging from 8:1 to 25:1 ⁸, values in severe contrast with the recommendations from national health agencies of approximately 4:1 ⁹. Lowering the Omega-6:Omega-3 ratio would reduce competition for the enzymes and facilitate the metabolism of more downstream products of Alpha-linolenic acid (ALA) (18:3ω-3).

Key facts

• There is convincing evidence that Linoleic acid (LA) and Alpha-linolenic acid (ALA) are essential fatty acids since they cannot be synthesized by humans.
• The acceptable range for total Polyunsaturated fatty acids (PUFAs) (Omega-6  fatty acids and Omega-3 fatty acids) is between 6 and 11% of total calories. The adequate intake to prevent deficiency is 2.5 to 3.5% of total calories. Therefore, the recommended range for Polyunsaturated fatty acids (PUFAs) is 6 to 11% of total calories.
• There is convincing evidence that replacing saturated fats with Polyunsaturated fatty acids (PUFAs) decreases the risk of coronary heart disease.
• There is convincing and sufficient evidence from experimental studies to set an acceptable intake to meet essential fatty acid needs for Linoleic acid (LA) and Alpha-linolenic acid (ALA) consumption.
• There is possible evidence that Polyunsaturated fatty acids (PUFAs) affect the risk of alterations in indices related to the metabolic syndrome.
• There is possible evidence of a relationship between Polyunsaturated fatty acids (PUFAs) intake and reduced risk of diabetes.
• There is insufficient evidence for establishing any relationship between Polyunsaturated fatty acids (PUFAs) consumption and cancer.
• There is insufficient evidence for establishing relationships between Polyunsaturated fatty acids (PUFAs) consumption and body weight and percent adiposity.

Mammalian cells cannot convert omega-6 to omega-3 fatty acids because they lack the converting enzyme, omega-3 desaturase. Omega-6 and omega-3 fatty acids are not interconvertible, are metabolically and functionally distinct, and often have important opposing physiological effects, therefore their balance in the diet is important ¹⁰.

This study showed a balanced omega-6/omega-3 ratio 1–2/1 is one of the most important dietary factors in the prevention of obesity, along with physical activity. A lower omega-6/omega-3 ratio should be considered in the management of obesity ¹⁰.

Because most diets are already very rich in omega-6 PUFAs, greater focus needs to be placed on incorporating omega-3 PUFAs into the diet. Dietary sources of omega-3 PUFAs are readily available but in limited quantities. Many foods contain alpha-linolenic acid (ALA), including certain vegetable oils, dairy products, flaxseed, walnuts and vegetables ¹¹. Fatty fish, such as mackerel, herring and salmon, provide an excellent source of the long-chain derivatives of ALA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) ⁹.

Omega-3 fatty acids are a type of polyunsaturated fats found in seafood, such as salmon, trout, herring, tuna, and mackerel, and in flax seeds and walnuts. EPA and DHA are long chain omega-3 fatty acids found in seafood. Omega-3 fats are one important type of polyunsaturated fat. Polyunsaturated fats are essential fats. That means your body can’t produce these and they’re required for normal body functions. So you must get them from food. Polyunsaturated fats are used to build cell membranes and the covering of nerves. They are needed for blood clotting, muscle movement, and inflammation.

A polyunsaturated fat has two or more double bonds in its carbon chain. There are two main types of polyunsaturated fats: omega-3 fatty acids and omega-6 fatty acids. The numbers refer to the distance between the beginning of the carbon chain and the first double bond. Both types offer health benefits.

Polyunsaturated fatty acids (PUFAs) can be further subdivided on the basis of the location of the first carbon-to-carbon double bond relative to the methyl terminus of the chain. For example, omega-3 and omega-6 fatty acids are two of the most biologically significant polyunsaturated fatty acid classes, and have their first carbon-to-carbon double bond on either the third or sixth carbon from the chain terminus, respectively. The final carbon in the fatty acid chain is also known as the omega carbon, hence the common reference to these fatty acids as omega-3 or omega-6 PUFAs.

Eating polyunsaturated fats in place of saturated fats or highly refined carbohydrates reduces harmful LDL cholesterol and improves the cholesterol profile. It also lowers triglycerides.

We don’t eat nearly enough omega-3, which can reduce our risk for heart disease and cancer. Good sources of omega-3 fatty acids include fatty fish such as salmon, mackerel, and sardines, all green leafy vegetables, flaxseeds, walnuts, canola oil, and unhydrogenated soybean oil.

Omega-3 fatty acids may help prevent and even treat heart disease and stroke. In addition to reducing blood pressure, raising HDL, and lowering triglycerides, polyunsaturated fats may help prevent lethal heart rhythms from arising. Evidence also suggests they may help reduce the need for corticosteroid medications in people with rheumatoid arthritis. Studies linking omega-3s to a wide range of other health improvements, including reducing risk of dementia, are inconclusive, and some of them have major flaws, according to a systematic review of the evidence by the Agency for Healthcare Research and Quality.

Omega-6 fatty acids have also been linked to protection against heart disease. Foods rich in linoleic acid and other omega-6 fatty acids include vegetable oils such as safflower, soybean, sunflower, walnut, and corn oils.

The latest research on nuts by the Harvard School of Public Health found that women who reported eating a half serving of peanut butter or a full serving of nuts five or more times a week showed as much as a 30% reduced risk of developing type 2 diabetes. And eating other nuts, like almonds, walnuts, and pecans, have been shown to have heart healthy benefits, including lowering “bad” LDL cholesterol. (Remember, walnuts are also a source of omega-3.)

Figure 4. Polyunsaturated Fatty Acids Structure

Figure 5. Omega-3 fatty acids (ALA, EPA & DHA) and Omega-6 fatty acids (LA & AA) structure

Footnotes: Omega-6 fatty acids are represented by Linoleic acid (LA) (18:2ω-6) and Arachidonic acid (AA) (20:4ω-6) and Omega-3 fatty acids by Alpha-linolenic acid (ALA) (18:3ω-3), Eicosapentaenoic acid (EPA) (20:5ω-3) and Docosahexaenoic acid (DHA) (22:6ω-3).

Monounsaturated fat

Monounsaturated fats (monounsaturated fatty acids or MUFAs) have a single carbon-to-carbon double bond. The result is that it has two fewer hydrogen atoms than a saturated fat and a bend at the double bond. This structure keeps monounsaturated fats liquid at room temperature. Eating food that has more monounsaturated fat (or “healthy fat”) instead of saturated fat (like butter) may help lower cholesterol and reduce heart disease risk. Research also shows that monounsaturated fats may benefit insulin levels and blood sugar control, which can be especially helpful if you have type 2 diabetes. However, monounsaturated fat has the same number of calories (9 calories or 37kJ) as other types of fat and may contribute to weight gain if you eat too much of it. Good sources of monounsaturated fats are olive oil, peanut oil, canola oil, avocados, most nuts, as well as high-oleic safflower and sunflower oils. The carbon-carbon double bond found in monounsaturated or polyunsaturated fatty acids can exist in the cis or trans configuration. When the two hydrogen atoms are on opposite sides of the double bond, the configuration is called trans. When the hydrogen atoms are on the same side of the double bond, the configuration is called cis. Monounsaturated fats (monounsaturated fatty acids) are found in high concentrations in olive oil, peanut oil, canola, avocados, almonds, safflower oils, hazelnuts, pecans, pumpkin seeds and sesame seeds and most nuts. Monounsaturated fats also are part of most animal fats such as fats from chicken, pork, beef, and wild game. When you dip your bread in olive oil at an Italian restaurant, you’re getting mostly monounsaturated fat.

The most common cis-configured monounsaturated fats (monounsaturated fatty acids or MUFAs) in daily nutrition is oleic acid (18:1 n-9), followed by palmitoleic acid (16:1 n-7), and vaccenic acid (18:1 n-7). Moreover, oleic acid represents the topmost monounsaturated fats (monounsaturated fatty acids or MUFAs) provided in the diet (~90% of all MUFAs) ¹. The major trans-configured monounsaturated fats (monounsaturated fatty acids or MUFAs) is elaidic acid (trans 18:1 n-9). Some MUFA—such as mystrioleic (14:1 n-5), gondoic (20:1 n-9), erucic (22:1 n-9) and nervonic (24:1 n-9) acid—are synthesized in minor concentrations endogenously using other monounsaturated fats (monounsaturated fatty acids or MUFAs) as precursors ².

Key facts

• There is convincing evidence that replacing carbohydrates with monounsaturated fats (monounsaturated fatty acids or MUFA) increases HDL “good” cholesterol concentrations.
• There is convincing evidence that replacing saturated fats (C12:0–C16:0) with monounsaturated fats reduces LDL “bad” cholesterol concentration and total/HDL cholesterol ratio.
• There is possible evidence that replacing carbohydrates with monounsaturated fats improves insulin sensitivity.
• There is insufficient evidence for establishing a relationship between monounsaturated fats consumption and chronic disease end points such as coronary heart disease or cancer.
• There is insufficient evidence for establishing a relationship between monounsaturated fats consumption and body weight and percent adiposity.
• There is insufficient evidence for establishing a relationship between monounsaturated fats intake and risk of diabetes.

Unsaturated fat vs Saturated fat

Foods high in monounsaturated fat

Monounsaturated fats help protect your heart by maintaining levels of good HDL cholesterol while reducing levels of bad LDL cholesterol.

Monounsaturated fats are found in high concentrations in:

• Olive, peanut, and canola oils
• Avocados and their oils/spreads
• Nuts such as almonds, hazelnuts, peanuts, pecans and their butters/spreads
• Seeds such as pumpkin and sesame seeds.

Table 2. Monounsaturated fat foods

What kind of fats are the healthier?

Unsaturated fats are those that are liquid at room temperature and can have beneficial effect on your heart. The two kinds of unsaturated fats are monounsaturated fat and polyunsaturated fat. Both of these unsaturated fats are typically liquid at room temperature. Unsaturated fats are in fish, such as salmon, trout and herring, and plant-based foods such as avocados, olives and walnuts. Liquid vegetable oils, such as soybean oil, corn oil, safflower oil, canola oil, olive oil, peanut oil, canola oil and sunflower oil, also contain unsaturated fats. Eaten in moderation, both kinds of unsaturated fats may help improve your blood cholesterol when used in place of saturated and trans fats. You want to include as many unsaturated fats in your diet because they can decrease bad cholesterol, contain high amounts of antioxidants such as Vitamin E, and contain essential omega-3 and omega-6 fatty acids. Unsaturated fats are typically classified by how many hydrogen bonds they have in their structure: either 1 (mono) or two or more (poly). Polyunsaturated fats are distinguished from saturated and monounsaturated fatty acids by the presence of two or more double bonds between carbons within the fatty acid chain. Polyunsaturated fatty acids (PUFAs) are frequently designated by their number of carbon atoms and double bonds. Alpha-linolenic acid (ALA), for example, is known as C18:3n-3 because it has 18 carbons and 3 double bonds and is an omega-3 (n-3) fatty acid. Similarly, eicosapentaenoic acid (EPA) is known as C20:5n-3 and docosahexaenoic acid (DHA) as C22:6n-3 ¹³. Omega-6 fatty acids (omega-6s) have a carbon–carbon double bond that is six carbons away from the methyl end of the fatty acid chain. Linoleic acid (C18:2n-6) and arachidonic acid (C20:4n-6) are two of the major omega-6s ¹³.

Vegetable oils are the healthy choice for frying and baking, and plant-based spreads, avocados or nut butters for sandwiches, toast and potatoes. These are healthier choices than butter or lard. Check food labels and compare the fat content in different products to help you choose ones that are lower in saturated fats. But remember, while this will help to lower your cholesterol level, you need to look at your whole diet to reduce overall risk. Many factors affect heart disease risk, not one food or nutrient alone. The Mediterranean diet is associated with reducing your risk of heart and circulatory disease. It includes plenty of fruit and vegetables, pulses, fish, nuts and seeds, and less butter, meat, full-fat dairy products and high-fat snacks, so it’s naturally higher in unsaturated fats and lower in saturated fats.

Polyunsaturated fats

Polyunsaturated fats also called polyunsaturated fatty acids (PUFAs) can help reduce bad cholesterol levels in your blood, which can lower your risk of heart disease and stroke ¹⁴. Polyunsaturated fats also provide nutrients to help develop and maintain your body’s cells. Oils rich in polyunsaturated fats also provide vitamin E, an important antioxidant vitamin. Oils rich in polyunsaturated fats also provide essential fats that your body needs but can’t produce itself, including omega-3 and omega-6 fatty acids. You must get essential fats through food. Omega-6 and omega-3 fatty acids are important for many functions in your body.

Omega-3 fatty acids (omega-3s) have a carbon–carbon double bond located three carbons from the methyl end of the chain. Omega-3s, sometimes referred to as n-3s, are present in certain foods such as flaxseed and fish as well as dietary supplements such as fish oil. Several different omega-3 fatty acids exist, but the majority of scientific research focuses on three: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) ¹³. Alpha-linolenic acid (ALA) contains 18 carbon atoms, whereas eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are considered long-chain omega-3s because eicosapentaenoic acid (EPA) contains 20 carbons and docosahexaenoic acid (DHA) contains 22 ¹³.

The human body can only form carbon–carbon double bonds after the ninth carbon from the methyl end of a fatty acid ¹⁵. Therefore, alpha-linolenic acid (ALA) and linoleic acid are considered essential fatty acids, meaning that they must be obtained from your diet ¹⁶. Alpha-linolenic acid (ALA) can be converted into eicosapentaenoic acid (EPA) and then to docosahexaenoic acid (DHA), but the conversion which occurs primarily in your liver is very limited, with reported rates of less than 15% ¹⁷. Therefore, consuming eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) directly from foods and/or dietary supplements is the only practical way to increase levels of these fatty acids in your body ¹³.

Alpha-linolenic acid (ALA) is present in plant oils, such as flaxseed, soybean, and canola oils ¹⁷. Eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are present in fish, fish oils, and krill oils, but they are originally synthesized by microalgae at the base of the marine food chain, not by the fish. As microalgae move up the food chain, fish acquire the omega-3s and accumulate them in their tissues ¹⁷.

After ingestion, dietary fats are brokendown in your intestines ¹⁵. The hydrolysis products—monoglycerides and free fatty acids—are then incorporated into bile-salt– containing micelles and absorbed into enterocytes, largely by passive diffusion. The process is efficient, with an absorption rate of about 95%, which is similar to that of other ingested fats ¹⁵. Within intestinal cells, free fatty acids are primarily incorporated into chylomicrons and enter the circulation via the lymphatic system ¹⁵, ¹⁸. Once in your bloodstream, lipoprotein particles circulate within your body, delivering lipids to various organs for subsequent oxidation, metabolism, or storage in fat tissue ¹⁸, ¹⁹.

Omega-3 fatty acids play important roles in your body as components of the phospholipids that form the structures of cell membranes ¹⁹. Docosahexaenoic acid (DHA), in particular, is especially high in the retina, brain, and sperm ¹⁹, ¹⁷, ²⁰. In addition to their structural role in cell membranes, omega-3 fatty acids along with omega-6 fatty acids provide energy for your body and are used to form eicosanoids. Eicosanoids are signaling molecules that have similar chemical structures to the fatty acids from which they are derived; they have wide-ranging functions in the body’s cardiovascular, pulmonary, immune, and endocrine systems ²¹, ¹⁶.

The eicosanoids made from omega-6 fatty acids are generally more potent mediators of inflammation, vasoconstriction, and platelet aggregation than those made from omega-3 fatty acids, although there are some exceptions ¹⁷, ²². Because both classes of omega-6 and omega-3 fatty acids compete for the same desaturation enzymes, alpha-linolenic acid (ALA) is a competitive inhibitor of linoleic acid metabolism and vice versa ²³. Similarly, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) can compete with arachidonic acid for the synthesis of eicosanoids. Therefore, higher concentrations of eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) than arachidonic acid tip the eicosanoid balance toward less inflammatory activity ²⁴.

Some researchers propose that the relative intakes of omega-6s and omega-3s, the omega-6/omega-3 ratio, may have important implications for the cause of many chronic diseases, such as cardiovascular disease (heart and blood vessel disease) and cancer ²⁴, but the optimal omega-6/omega-3 ratio—if any—has not been defined ²⁵. Others have concluded that such ratios are too nonspecific and are insensitive to individual fatty acid levels ²⁶, ²⁷, ²⁸. Most agree that raising eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) blood levels is far more important than lowering linoleic acid or arachidonic acid levels.

Nontropical vegetable oils high in polyunsaturated fat include:

• Canola oil
• Corn oil
• Soybean oil
• Sunflower oil.

Foods high in polyunsaturated fats include:

• Fatty, or oily fish, including anchovies, herring, mackerel, black cod, salmon, sardines, bluefin tuna, whitefish, striped bass and cobia. These fish are high in omega-3 fatty acids.
• Some nuts and seeds, including walnuts, flaxseeds and sunflower seeds.
• Tofu/soybeans.

Figure 7. Polyunsaturated fat foods

Monounsaturated fats

Monounsaturated fats also called monounsaturated fatty acids (MUFAs) can also help reduce bad cholesterol levels in your blood, which can lower your risk of heart disease and stroke ²⁹, ³⁰. Monounsaturated fats also provide nutrients to help develop and maintain your body’s cells. Oils rich in monounsaturated fats also provide vitamin E, an important antioxidant vitamin. Olive oil is a type of oil that contains monounsaturated fats. For good health, consume foods that contain monounsaturated fats in place of those that contain saturated fats and/or trans fats. Oils that contain monounsaturated fats are typically liquid at room temperature but start to turn solid when chilled.

Nontropical vegetable oils high in monounsaturated fats include:

• Olive oil
• Canola oil
• Peanut oil
• Safflower oil
• Sesame oil

Foods high in monounsaturated fats include:

• Avocados.
• Peanut butter.
• Some nuts and seeds, including almonds, hazelnuts, pecans, pumpkin seeds and sesame seeds.

Figure 8. Monounsaturated fat foods

What are Healthy fats?

Healthy fats include:

• Monounsaturated fats
• Polyunsaturated fats (omega-3 and omega-6).

The healthier fats are unsaturated fats. They can be found in sunflower oil, safflower oil, peanut and olive oils, poly- and mono-unsaturated margarine spreads, nuts, seeds and avocado. These are much better for you than the saturated fat found in butter, cream, fatty meats, sausages, biscuits, cakes and fried foods.

Foods that contain healthy monounsaturated fats include:

• Avocados and their oils/spreads
• Unsalted nuts such as almonds, cashews and peanuts and their butters/spreads
• Olives and their oils/spreads
• Cooking oils made from plants or seeds, including: olive, canola, peanut, sunflower, soybean, sesame and safflower.

Foods that contain healthy polyunsaturated fats (omega-3 and omega-6) include:

• Oily fish like salmon, mackerel and sardines
• Tahini (sesame seed spread)
• Linseed (flaxseed) and chia seeds
• Soybean, sunflower, safflower, canola oil and margarine spreads made from these oils
• Pine nuts, walnuts and brazil nuts.

It is important to choose foods with the healthiest type of fat such as avocados, olives, nuts and seeds, and use healthy oils for cooking, for example, olive, canola, sunflower, peanut and soybean oil.

Reduce the amount of highly processed food you eat such as baked goods including cakes, biscuits and pastries, along with processed meat, and fried and takeaway foods. These foods are high in saturated and trans fats, added sugar and salt, and are not part of a heart-healthy eating pattern. Try to have these foods only sometimes and in small amounts.

Many Americans eat more fat than they need, which can lead to weight gain and heart disease.

What are Unhealthy fats?

Unhealthy fats include:

• Saturated fat. Saturated fat and trans fat are ‘unhealthy’ fats. They can raise your ‘bad’ (non-HDL) cholesterol in your blood. Too much cholesterol can increase your risk of having:
  • a stroke
  • a heart attack
  • vascular dementia.
• Trans fat. Trans fatty acids are unhealthy fats that form when vegetable oil goes through a process called hydrogenation. This leads the fat to harden and become solid at room temperature. Hydrogenated fats, partially hydrogenated oils (PHOs) or “trans fats,” are often used to keep some foods fresh for a long time. Trans fats are unsaturated fats that are artificially turned into saturated fats and increase heart disease and stroke risk by raising bad LDL cholesterol and decreasing good HDL cholesterol levels. High LDL (bad) cholesterol along with low HDL (good) cholesterol levels can cause cholesterol to build up in your arteries (blood vessels). This increases your risk for heart disease and stroke. Trans fats have also been known to increase the risk of developing type 2 diabetes. Trans fats are most commonly found in fried foods, frozen baked products such as pizza, non-dairy coffee creamers, vegetable shortenings, some margarines, crackers, cookies, snack foods, and other foods made with or fried in partially hydrogenated oils (PHOs). Because of the health risks from trans fats, the United States Food and Drug Administration (FDA) has banned food manufacturers from adding partially hydrogenated oils (PHOs) to foods. Although the food industry has greatly reduced the use of trans fat in recent years, trans fat may still be found in many fried, packaged, or processed foods. There are very small amounts of naturally occurring trans fat in meats and dairy from grazing animals, such as cows, sheep and goats. You should avoid foods made with hydrogenated and partially hydrogenated oils (such as hard butter and margarine). They may contain high levels of trans fatty acids. It is important to read nutrition labels on foods. This will help you know what kinds of fats, and how much, your food contains.

Foods rich in unhealthy fats include:

• Animal fats including butter, ghee and lard along with the visible fat/skin on meat
• Hydrogenated plant oils like copha, vegetable shortening and some margarines
• Coconut oil
• Processed foods such as baked goods (cakes, biscuits and pastries), processed meat ( bacon, sausages, salami) and fried and takeaway foods.

Replace foods rich in saturated and trans fats with foods rich in healthy unsaturated fats as part of a healthy diet.

It is important to choose foods with the healthiest type of fat such as avocados, olives, nuts and seeds, and use healthy oils for cooking, for example, olive, canola, sunflower, peanut and soybean oil.

Reduce the amount of highly processed food you eat such as baked goods including cakes, biscuits and pastries, along with processed meat, and fried and takeaway foods. These foods are high in saturated and trans fats, added sugar and salt, and are not part of a heart-healthy eating pattern. Try to have these foods only sometimes and in small amounts.

Many Americans eat more fat than they need, which can lead to weight gain and heart disease.

How much fat do I need?

To prevent any fatty acid deficiencies it is recommended that you consume at minimum 1g of fat per kg of body weight per day. According to the Dietary Guidelines for Americans ⁴, fats should make up 20 to 35 percent of your total daily calorie intake (for adults) with most fats coming from sources of polyunsaturated fats and monounsaturated fats, such as fish, nuts, and vegetable oils. The Dietary Guidelines for Americans also recommend getting less than 10 percent of your calories from saturated fats and keeping trans fat consumption as low as possible for general health and the prevention of chronic disease, including cancer and heart disease ⁴. The American Heart Association recommends aiming for a dietary pattern that achieves less than 6% of total calories from saturated fat ³¹, ³². For example, if you need about 2,000 calories a day, no more than 120 calories should come from saturated fat. That’s about 13 grams or less of saturated fat per day ³¹. Many Americans eat more fat than they need, which can lead to weight gain and heart disease. The nutrition labels on your food’s packaging will show you the amount of total fat and saturated fat you are eating. Looking at the amount of saturated fat in your food will help you keep to the recommended daily intake.

Fat needs will vary by individual and will depend largely on your body composition goals and body types. For example, dietary fat recommendations are slightly higher in competitive athletes than non-athletes to promote health, maintain healthy hormone function, and maintain energy balance. Typical recommendations for athletes are 30 to 50% of total energy intake. You need to eat some fat even when you are trying to lose weight. For those attempting to lose body fat, 0.5 to 1 fat per kg of body weight per day should be consumed per day to avoid essential fatty acid deficiency. For healthy children ages 1 to 3, ages 4 to 18, and adults, approximately 30 to 40%, 25 to 15%, and 20 to 35% of daily energy intake should come from fat, respectively ³³. The human body needs small amounts (3 to 6 grams) of essential fatty acids (Omega-6 fatty acids and Omega-3 fatty acids). Fat is important for many body processes. Fat helps your body absorb nutrients and move nutrients around your body. Some fat is necessary as a carrier for the fat-soluble vitamins A, D, E, and K. Fat is the main source of energy storage in your body, fat contributes to cellular structure and function, fat keeps you warm, and protects your organs ³⁴, ³⁵, ³⁶. Fat also helps with hormone production. Therefore your diet should not be devoid of fat. However, because fat is calorically dense (1 gram of fat has 9 calories of energy), it is often decreased on weight-loss diets to reduce energy intake.

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are omega-3 fatty acids found in varying amounts in seafood such as cold-water fish like salmon, tuna, herring, and mackerel, as well as in fish oil supplements and seaweed. Eating 8 ounces per week of seafood may help reduce the risk for heart disease.

Approximately 5 to 10% of your daily fat energy intake should consist of Omega−6 fatty acids (linoleic acid) and 0.6 to 1.2% of Omega−3 fatty acids (alpha-linolenic acid, eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) ³⁷. Both omega−6 fatty acids (linoleic acid) and omega−3 fatty acids (alpha-linolenic acid, eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) are considered essential fatty acids, meaning that they must be obtained from your diet ¹⁶. Apha-linolenic acid (ALA) can be converted into eicosapentaenoic acid (EPA) and then to docosahexaenoic acid (DHA), but the conversion which occurs primarily in your liver is very limited, with reported rates of less than 15% ¹⁷, ³⁸. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are essential fatty acids, meaning the body can’t produce them and they must come from your diet ¹⁵. Therefore, consuming eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) directly from foods and/or dietary supplements is the only practical way to increase levels of these fatty acids in your body.

Some researchers propose that the relative intakes of omega-6s and omega-3s, the omega-6/omega-3 ratio, may have important implications for the cause of many chronic diseases, such as heart and blood vessels disease (cardiovascular disease) and cancer ²³, but the optimal ratio, if any, has not been defined ³⁹. Others have concluded that the omega-6/omega-3 ratios are too nonspecific and are insensitive to individual fatty acid levels ²⁶, ²⁷, ²⁸.. Most agree that raising EPA and DHA blood levels is far more important than lowering linoleic acid or arachidonic acid levels ³⁸.

For someone who weighs 150lbs (68kg), this would equate to 34-68g fat per day. Using both of these references you can calculate your daily fat needs:

To calculate your daily fat needs:

• Convert body weight in pounds to kilograms (round to the nearest 10th).
 Multiply weight in kilograms by 1.

Let’s look at an example:

• Convert pounds into kilograms 150lbs / 2.2 = 68.2kg

The recommended fat intake is 1 gram per kilogram of body weight per day

• 68.2kg (1g grams of fat per kilogram) = 68.2g of fat per day

Weight loss diets that are moderate to low in fat (20 to 30% of calories) are called “balanced deficit” diets because they maintain a reasonable balance among macronutrients similar to that recommended in MyPlate, DASH, and the Dietary Guidelines for Americans ⁴, ⁴⁰. They tend to achieve most of the caloric deficit by reducing fat from the typical level in North American Diets of about 34% or more of calories to 20 to 30% fat, 15% protein, and 55 to 65% of calories from carbohydrates. Some examples of low fat diets are the Weight Watchers Diet (25% fat, 20% protein, and 55% carbohydrate, with 26 grams of dietary fiber), Jenny Craig, the National Cholesterol Education Program Step 1 diet (25% fat), diets based on the MyPlate, the DASH diet, the Shape up and Drop 10 diet of Shape Up! America and the Nutrisystem diet ⁴¹. Popular diet books using this approach include The Biggest Loser Diet, The Mayo Clinic Diet and The Engine 2 Die ⁴¹. These dietary patterns have been extensively reviewed and appear to be effective for weight reduction on low calorie diets for most individuals ⁴¹.

Very low-fat diets such as the Pritikin Diet ⁴², the Ornish Diet ⁴³ and The Spark Solution Diet ⁴⁴ have been advocated not only for weight reduction, but also for improving cardiovascular risk profiles. The Ornish Diet ⁴³, which is very low in fat (13% of calories) and saturated fat, very high in carbohydrate (81% of calories) and very high in fiber (38 grams), is part of a program that includes nonsmoking, exercise and behavior modification. The Ornish Diet ⁴³ was shown to reduce some cardiovascular risk factors in a limited long term study. For those who can adhere to the Ornish regime it may be helpful. However, it may not be appropriate for all populations, such as diabetics.

Are ‘low fat’ and ‘lighter’ foods better for me?

A lower fat option might not be better for you. For a food or drink to be labelled as:

• ‘lite’, ‘light’ or ‘lighter’, it must have at least 30 percent less fat than the original product
• ‘low fat’ or ‘reduced fat’, it must have less than 3g of fat per 100g and in some countries, the pack’s label will have the fat content colored green.

Sometimes, the fat will be replaced with more sugar or salt to make it taste like the original product. This might not make the lower fat option healthier.

Even if your food’s packaging says it’s lower fat, you might want to check its nutrition label. You can check the amount of ‘total fat’ and the amount of ‘saturated fat’ per serving on the label.

How Much Good Fats Do You Really Need ?

In 1999, the International Society for the Study of Fatty Acids and Lipids agreed upon a recommendation table on daily intake of fatty acids as a foundation for further discussions ². Polyunsaturated fatty acids (PUFAs) with 18 carbon (C18) atoms such as linoleic (18:2 ω-6), and α-linolenic (18:3 ω-3) are known as essential fatty acids in human nutrition ⁴⁵. These fatty acids, although regarded as an indispensable component for cell structure and development and function, cannot be synthesized by the human body. Nutritionists recommend a balanced lipid intake corresponding to a total amount of fats equal to 25 to 30% of total calories with a ratio in fatty acids as follows: 1-Saturates (6–8%), 2-Monounsaturates (12–14%), 3- Polyunsaturates as a ω-6 (6–7%), and 4-Polyunsaturates as a ω-3 (0.5–1.5%) ⁴⁶. The American Heart Association recommends aiming for a dietary pattern that achieves 5% to 6% of calories from saturated fat ⁴⁷. Saturated fatty acids increase plasma cholesterol level and acts as “promoters” of certain cancer development (e.g., colon, breast, and perhaps uterus and prostate).

Adequate intake levels for adults were specified with respect to α-linolenic acid (ALA or Omega-3 fatty acid 18:3ω-3), eicosapentaenoic acid (EPA or Long Chain Omega-3 fatty acid 20:5ω-3), docosahexaenoic acid (DHA or Long Chain Omega-3 fatty acid 22:6ω-3), as well as upper limits for linoleic acid (LA or Omega-6 fatty acids), trans-fatty acids, and saturated, given as % of total energy content, respectively. Given a total fat range from 15% to 40% of total energy content, there is no precise value (i.e., % of total energy content in the form of MUFA) was given by the panel ⁴⁸. According to the Joint FAO/WHO Expert Consultation Committee, MUFA intakes should be determined by calculating the difference: MUFA (% of total energy content) = total fat (% of total energy content) − SFA (% of total energy content) − PUFA (% of total energy content) − TFA (% of total energy content). Accordingly, MUFA intakes (% of total energy content) will range with respect to the total fat and fatty acid composition of the diet ⁴⁹.

The debate continues on the optimal dietary fatty acid composition, but the evidence supporting Monounsaturated Fatty Acid (MUFA) as the healthy dietary fatty acid is weak. Even when considering the food source of MUFA (plant vs animal), there is little evidence to support recommendations to increase dietary MUFA for coronary heart disease prevention. However, since no detrimental effects of MUFA-rich diets were reported in the literature to date, there is no evidence speaking against the consideration of MUFAs in dietary guidelines. Further studies dealing with long-term effects of MUFA on biomarkers of obesity, diabetes, and cardiovascular diseases as well as clinical endpoints are needed to clarify the potential benefits of MUFA-rich diets in primary and secondary prevention.

On the other hand, increasing dietary Polyunsaturated Fatty Acid (PUFA) consistently appears to provide benefit. A considerably larger number of meta-analyses explored the effects of Polyunsaturated Fatty Acids (PUFAs) on maintenance or reduction of body weight as well as biomarkers of impaired glucose metabolism or cardiovascular disease or coronary heart disease than there are systematic reviews and meta-analyses dealing with the corresponding impact of Monounsaturated Fatty Acids (MUFAs). Consequently, the international recommendations for Polyunsaturated Fatty Acid (PUFA) are more consistent than those for MUFA, averaging a value of 10% of total energy content for healthy persons for the most part. If MUFA recommendations are given at all, they vary between 12% and 25% of total energy content, equaling a remarkable range of ~30–70 g/day for a 2.500 kcal-diet. Prestigious authorities and organizations such as the National Institute of Medicine, the EFSA, the USDA and the ADA do not provide specific recommendation for MUFAs either for healthy people or for patients in need of diabetic or cardiovascular management.

Most of us get too much fat, and too much unhealthy fat. Most experts recommend that we get 30% of our calories from good fat, although we can survive fine on as little as 20%, even 10%. If you’re like most of us, you’re getting plenty of fat – most Americans consume about 40% of their calories from fats in meat, butter, cheese, baked goods, etc.

To make the switch to heart-healthy fats, start by avoiding the truly unhealthy fats – trans fatty acids. These trans fats come from vegetable oils that were chemically modified so they are solid like butter. Because these oils don’t spoil as quickly as butter, they are used in most packaged cookies, chips, crackers and other baked goods sold in the supermarket, as well as in margarines.

Focus on replacing foods high in saturated fat with foods that include monounsaturated fats and polyunsaturated fats.

But a word of caution — don’t go overboard even on healthy fats. All fats, including the healthy ones, are high in calories. So consume monounsaturated and polyunsaturated fats instead of other types of fat, not in addition to them.

Here are some tips to help you make over the fat in your diet:

• To avoid trans fat, check food labels and look for the amount of trans fat listed. By law a serving of food containing less than 0.5 grams of trans fat can be labeled as 0 grams. Therefore, it’s important to also check ingredient lists for the term “partially hydrogenated.”
• Use oil instead of solid fats. For example, saute with olive oil instead of butter, and use canola oil when baking.
• Prepare fish, such as salmon and mackerel, instead of meat at least twice a week to get healthy omega-3 fatty acids. Limit sizes to 4 to 6 ounces of cooked seafood a serving, and bake or broil seafood instead of frying.
• Choose lean meat and skinless poultry. Trim visible fat from meat and poultry, and remove skin from poultry.
• Snack smart. Many popular processed snack foods are high in fat, especially solid fats. Be sure to check food labels for saturated fat. Better yet, snack on whole fruits and vegetables.

Summary

• Decreased saturated fatty acid intake decreases blood total cholesterol and LDL cholesterol concentrations.
• Replacement of saturated fatty acids with polyunsaturated and/or monounsaturated fatty acids decreases blood total cholesterol and LDL cholesterol concentrations.
• Most of us eat too much fat, and too much unhealthy fat. Most experts recommend that we get 30% of our calories from good fat, although we can survive fine on as little as 20%, even 10%. If you’re like most of us, you’re getting plenty of fat – most Americans consume about 40% of their calories from fats in meat, butter, cheese, baked goods, etc.

Are unsaturated fats bad?

No. Unsaturated fats are in fish, such as salmon, trout and herring, and plant-based foods such as avocados, olives and walnuts. Liquid vegetable oils, such as soybean oil, corn oil, safflower oil, canola oil, olive oil, peanut oil, canola oil and sunflower oil, also contain unsaturated fats. Eaten in moderation unsaturated fats may help improve your blood cholesterol when used in place of saturated and trans fats. You want to include as many unsaturated fats in your diet because they can decrease bad LDL cholesterol, contain high amounts of antioxidants such as Vitamin E, and contain essential omega-3 fatty acids and omega-6 fatty acids.

Foods high in unsaturated fat

There are two types of “good” unsaturated fats:

1. Monounsaturated fats are found in high concentrations in:
   • Olive, peanut, and canola oils
   • Avocados and their oils/spreads
   • Nuts such as almonds, hazelnuts, peanuts, pecans and their butters/spreads
   • Seeds such as pumpkin and sesame seeds.
2. Polyunsaturated fats (omega-3 and omega-6) are found in high concentrations in:
   • Soybean, sunflower, safflower, canola oil, corn, flaxseed and margarine spreads made from these oils
   • Pine nuts, walnuts and brazil nuts.
   • Flax seeds
   • Tahini (sesame seed spread)
   • Linseed (flaxseed) and chia seeds
   • Oily fish like salmon, mackerel and sardines
   • Canola oil – though higher in monounsaturated fat, it’s also a good source of polyunsaturated fat.

It is important to choose foods with the healthiest type of fat such as avocados, olives, nuts and seeds, and use healthy oils for cooking, for example, olive, canola, sunflower, peanut and soybean oil.

Reduce the amount of highly processed food you eat such as baked goods including cakes, biscuits and pastries, along with processed meat, and fried and takeaway foods. These foods are high in saturated and trans fats, added sugar and salt, and are not part of a heart-healthy eating pattern. Try to have these foods only sometimes and in small amounts.

Many Americans eat more fat than they need, which can lead to weight gain and heart disease.

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