The truth is we all need some fat in our diet. It is an essential component of our diet and it has numerous functions in the body. However, it is also true that too much of a particular kind of fat can have negative effects on our health by raising cholesterol, which increases the risk of heart disease, obesity etc. Fat is mostly seen as the “enemy” of a fit and healthy body but this is not true. What counts as fat? Are some fats better than others? In this week’s article learn the facts about this nutrient and why you shouldn’t be afraid of including it in your meals.
Lipids are one the essential nutrients in our diet along with carbohydrates, proteins, vitamins and minerals. Although the term lipid is often used as a synonym for fat, the truth is fats are a subgroup of lipids called triglycerides. Lipids also include many other subgroups like fatty acids and cholesterol. Lipids are insoluble in water, either solid or liquid at room temperature, depending on their structure and composition. When consumed, they are metabolized and oxidized to release large amounts of energy and therefore they are very useful to living organisms. Depending on their chemical structure fatty acids are categorised into saturated fats and unsaturated fats, which are the main points of focus of this article. Unsaturated fats can be further divided into cis fats, which are the most common in nature, and trans fats, which are rare in nature but present in highly processed foods.
Lipids can be synthesized in the body using complex biosynthetic pathways. There are, however, some essential lipids that need to be obtained from the diet. These include essential fatty acids (EFAs), linoleic acid (LA), and a-linolenic acid (LNA). These help in formation of polyunsaturated fatty acids (PUFAs) which are used in cellular structures and as precursors for the biosynthesis of important molecules.
So, the question is which fats should we be eating more of? But first of all, we need to know all the reasons why we need fat in our food!
Role of lipids in the body
It is now known that lipids play a much more important role in the body than previously believed; in fact, they have a diverse and widespread biological role in the body.
- They provide energy for living organisms – providing more than twice the energy content compared with carbohydrates and proteins.
- They function as molecular messengers and signalling molecules in the body.
- They serve as the structural building material of all membranes of cells and organelles.
- A minimum amount of dietary fat is important because it helps in absorption of fat-soluble vitamins (A, D, E and K) and carotenoids.
- The layers of fat under the skin (subcutaneous fat) help in insulation and protection from cold and maintaining a steady temperature.
- Lipids are also biomarkers of disease and are involved in several pathological conditions. Lipids are also known to play a role in genetic modification and increase the risk of chronic disease. PUFA in diet has been proven to reduce risk of cardiovascular disease and cancers. In addition, n-3 fatty acids can minimize the symptoms of chronic inﬂammatory diseases like rheumatoid arthritis and inﬂammatory bowel disease (IBD).
- PUFAs can also influence gene expression, which extremely important in new born babies.
Fats to cut down: Saturated & Trans fats
- Saturated fat
According to the British Dietetic Association (BDA), most people in the UK consume about 20% more saturated fat than the recommended maximum which is 30g for men and 20g for women per day. Eating a diet high in saturated fat can cause an increase in the level of blood cholesterol which builds up in the arteries and increases the risk of heart disease. In order to reduce your saturated fat intake, avoid foods such as fatty meats (sausages, meat pies), hard cheeses and full fat cream, butter/lard, cakes, biscuits and pastries. Yes, it might seem quite difficult but cutting down does not mean eliminate!
- Trans fats
Trans fats are found naturally at low levels in foods like meat and dairy products. They are mostly found in processed foods containing hydrogenated vegetable oil. Like saturated fats, trans fats can raise cholesterol levels in the blood, lead to weight gain etc. This is why the recommendation for trans fats is that they should make up no more than 2% of the energy (calories) we get from our diet. For adults, this translates as no more than 5g a day. On average, people in the UK eat about half the recommended maximum as most of the supermarkets in the UK have removed hydrogenated vegetable oil from all their own-brand products and public health campaigns have stresses the importance of reducing consumption of such products.
Fats we can eat more of: Unsaturated fats
The good news is you don’t need to cut down on every type of fat. Unsaturated fats are not only good for us, but most people should be eating more of them as they help lower blood cholesterol. Sources of unsaturated fats, such as omega-3 essential fatty acids are oily fish (salmon, sardines and mackerel), olive oils, nuts, seeds and avocados.
Tips on eating less fat
Checking the nutrition labels on food packaging can help you to reduce the amount of fat you eat. You should opt for the low fat foods, which means the product contains less than 3g of total fat per 100g. Go for the skim or semi-skim dairy products and reduce butter and spreads when cooking. In addition, buy lean cuts of meat that you could grill, bake, or steam food rather than frying or roasting, so that you won’t need to add any extra fat. On the other hand, increase consumption of oily fish, add seeds to your salads and try nuts as snacks once or twice a week. Keep in mind that a balanced nutrition should include all food groups in moderation.
By Kleio Bathrellou
Associate Nutritionist & Certified Sports Nutritionist