Nutrition: The Role of Fat

There is no question that fat is the most maligned of the macronutrients. Most of us try to avoid fat, and we have been led to believe that it is responsible for all of our health and weight woes.

The truth is, fat is a necessary component of a healthy diet. As an important part of our cells, it plays a role in protecting our bodies, and can also improve heart health and keep our cholesterol levels in check. However, these tasks all require that we ingest the right kinds of fat, and in the right amounts.

What are the Types of Fat?

There are several types of fat, and some are good for the body while others can be severely detrimental.

The healthy, or unsaturated, fats are divided into monounsaturated and polyunsaturated. These fats are good for your heart, reduce inflammation and also help to regulate cholesterol levels. They are found in foods such as nuts, especially almonds, hazelnuts and pecans, fish, oils such as olive, peanut, and canola, and avocadoes.

The fats that fall into the unhealthy category are known as saturated fats. These appear in red meat, whole-milk dairy products, and vegetable oil. Because our bodies already produce all the saturated fat they need, it really isn’t a necessary component of our diet. Saturated fats can do damage to the cardiovascular system, and intake should be limited.

Recently, there has been a great deal of concern raised regarding trans fats, or trans fatty acids. Found in hydrogenated oils such as margarine and many of the frying oils used in fast food restaurants, trans fats are extremely bad for the heart. They raise the bad cholesterol levels in the bloodstream and increase the risk of heart disease. Trans fats should be eliminated from the diet altogether if possible.

How Much Fat is Needed?

Depending on age, fat should make up anywhere from 20-35% of your diet. Almost all of this should be of the healthy, unsaturated type. The exception to this is children under two, who have different nutritional needs from adults. Fat is important in brain and eye development for babies and infants, and a low-fat diet can be detrimental to this. Unless there is a history of heart disease in the family, children under two should have full-fat versions of foods such as dairy products.

Although low-fat diets have been popular for many years, new research indicates that there is little evidence to support their effectiveness. Since low-fat and fat-free version of products appeared on the shelves of American grocery stores, there has been almost no change in the level of obesity or cardiovascular disease in the American people. Studies have shown that the type of fat, and not the amount, determines the risk for heart disease. While two people may both consume the proper percentage of fat, the one who eats more saturated fat will be at a higher risk of heart disease.

The key to ensuring you are getting the right kind of fat and avoiding the wrong one is to read nutrition labels. These labels will tell you how many grams of fat the food contains per serving, as well as whether the fat is saturated or unsaturated. This is your best tool for controlling your fat intake.

By ensuring your diet contains the right amount of unsaturated fats, you can help to maintain heart health as well as keep your weight under control.

Fats

Fats are important components of a healthy diet. They provide our body energy. It is estimated that about 33-35% of our daily calories intake is in the form of fats (Fats provide more than twice as much energy as either carbohydrate or protein). Besides, fats also help to transport fat-soluble vitamins such as vitamins A, D and E, produce hormones and form part of the structure of cell membranes.

Fats are made up of mainly fatty acids and these fatty acids can be divided into three main categories:

  • Saturated fatty acids
  • Polyunsaturated fatty acids (for example: omega 3 and omega 6 fatty acids)
  • Monounsaturated fatty acids

All three types of fatty acids exist in fat-containing food. However, the proportion of each fatty acids can be different.

Ideal Amounts of Different Fats in the Diet

Nutrients Children, 1-3 year old Children, 4-18 year old Adults
Fat 30-40% of the total energy intake 25-35% of the total energy intake 25-35% of the total energy intake
Carbohydrates 45-65% 45-65% 45-65%
Protein 5-20% 10-30% 10-35%

Saturated Fats

Foods that are high in saturated fatty acid:

Food / 100g Saturated Fatty Acid (g) Total Fat (g)
Creamed coconut block 58.5 68
Suet, animal 56 100
Butter 53.5 80
Suet, vegetable 45 88
Lard 41 100
Hard margarine 35 80
Cream cheese 30 48
Double cream 30 48
Cheddar cheese, full-fat 21.5 34
Chocolate 18.5 31
Fried bacon, lean and fat 16 41
Shortcrust pastry 10 28
Pork pie 10 27
Potato crisps 9 37
Minced beef 7 16

How Much Fat Should You Eat?

Decrease your intake of saturated and trans fats is good for your health. You can eat more plant-based foods and less animal-based and commercial product foods. Polyunsaturated fats such as omega 3 and omega 6 fatty acids are essential to our health because our body cannot make them on its own. Breast milk contains DHA naturally, an omega 3 fatty acid which helps the brain development.

Dietary reference intake (DRIs): recommended intakes for infants, children, pregnant women and breastfeeding moms.