A Little Look Into Fats.

Fatty acids are the major forms of dietary fat and mainly exist in foods in the triglyceride form; however, they are usually categorized by their saturation status (e.g., monounsaturated, polyunsaturated). All fats contain both saturated fatty acids and unsaturated fatty acids but are classified into a category based on how much of each they contain. It is important to note the individual health effects of each fatty acid on health:

When it comes to fatty acids, there are four main kinds:

1. Saturated fatty acids (SFA)

2. Monounsaturated fatty acids (MUFA)

3. Polyunsaturated fatty acids (PUFA)

4. Trans fatty acids (TFA)

   
   

There are numerous unique fatty acid molecules within each of these main subtypes of fat, and sometimes these molecules have divergent effects due to their unique properties as well as the foods they exist in.

Now, when it comes to dietary recommendations, ‘total fats’ are often the focus, suggesting roughly 20-35% of energy coming from them. Total fats encompass all these fatty acids in one category. This recommendation is from the Institute of Medicine and the Food and Agriculture Organization of the United Nations and is supported by many other organizations. However, the American Heart Association suggests that 25-35% of daily calories should come from fats. From an energy intake standpoint, it makes sense that fats are the lowest percentage macronutrient in your diet, as fats are very calorie-dense, containing 9 kcal/g compared to carbohydrates and protein, which both contain 4 kcal/g. It is important to note that most individuals eat more than their energy requirements, and perhaps rather than focusing on total fat recommendations (to avoid increased consumption of SFA and TFA), we should look closer into the type of fatty acid consumed and recommended. Typically, it is suggested that we have around 70g of fat per day as part of a balanced diet with most coming from USFA; we need fats for the normal function of our bodies.

Each fatty acid’s structure is different, so it is reasonable to suggest they have different effects on our bodies. Currently, it is generally recommended to replace saturated fat with unsaturated fat and to avoid trans fats as much as possible. Numerous studies have assessed the effects of dietary fatty acids on blood lipid levels, but these fatty acids also influence other areas, such as insulin resistance, endothelial function, electrophysiologic phenomena, carcinogenesis, and systemic inflammation. In addition to cardiovascular disease, it has been associated that some fatty acids have been linked to the incidence of other chronic diseases: type 2 diabetes, cancers, multiple sclerosis, and respiratory diseases.

Below is a little break-down into each fatty acid:

Saturated fats are typically solid at room temperature and are primarily found in animal products like red meats, butter, cheese, and whole milk. They are also found in items such as coconut oil and palm oil. This type of fat is typically known as the ‘bad fats’ because excessive intake of saturated fats can raise LDL (the bad cholesterol that can cause unwanted health conditions). Current guidelines recommend limiting saturated fats in the diet.

Next, we have unsaturated fats, which are liquid at room temperature and are considered to be better for your health. This is then split into monounsaturated fats and polyunsaturated fats. MUFA is said to improve blood cholesterol levels and reduce inflammation. This is found in olive oil, avocados, nuts, and canola oil. PUFA is found in fish, specifically fatty fish, flaxseeds, walnuts, and soybean oil. This type of fat includes essential fatty acids like omega-3 and omega-6, which your body cannot make and needs to get from the diet. These types of fats can improve heart health and reduce LDL.

Finally, we have trans fats, which are the most artificial fats created through hydrogenating vegetable oils to make them semi-solid. TFA is found in hard cooking and pastry fats, cakes, and biscuits, as well as being formed when reheating frying oil. This type of fat tends to be found in processed foods, baked goods, and some margarines. These trans fats are also said to increase LDL cholesterol, decrease HDL cholesterol (the good cholesterol), and increase your risk of conditions like heart disease, so their consumption should be minimized.