Updated: Sep 23, 2021
Dietary fat is arguably the most contentious nutrient in the nutrition world. Fat is an umbrella term donated to a wide array of nutrients that differ in their structure and function. Grouping fats together can be misleading as different fats have different roles and therefore differ in their benefit and risk.
Here I will help dispel any myths around the fats we consume. I will provide scientific led nutrition advice on why fats are needed for our health.
Why we need fat
Fats are a major source of energy for the body, and they are also an important structural component of our cells. They help in the absorption of specific vitamins while providing essential fatty acids in the form of omega-3 and omega-6. So, it seems strange to categorise a nutrient that is essential as inherently 'bad', this is where distinctions are needed.
Everything in moderation
Overconsumption of fat will increase the likelihood of weight gain, and overconsumption of certain fats will increase the risk of developing undesirable conditions such as cardiovascular disease (CVD). It is important to keep in mind that fat is found in foods, and foods contain a variety of nutrients and these nutrients all interact.
If a nutrient has undesirable outcomes in an isolated form then this does not mean foods containing this nutrient will have undesirable outcomes themselves, as there can be other nutrients within the food that stop the negative action of others... more on this later on!
Fat and cholesterol
Fat intake does strongly influence our blood lipids, such as the total volume of ‘bad’ low-density lipoprotein cholesterol (LDL-C) and ‘good’ high-density lipoprotein cholesterol (HDL-C). Dietary fat recommendations are designed to best achieve a healthy blood lipid profile which reduces the risk of developing heart disease, while still providing a sufficient amount for essential different bodily functions.
Good examples of healthy fats
It is widely recommended to preferentially consume mono and poly-unsaturated fats. These are found in a variety of food groups including:
Monounsaturated fats can be synthesised in our bodies and obtained from the diet, and constitute an important part of our total fat intake. They help maintain a healthy blood lipid profile, and research has shown a reduced risk of CVD when replacing monounsaturated fats with saturated fat.
Polyunsaturated fats are essential to consume from the diet, as they contain two forms of fatty acids in omega-3 and omega-6 which our bodies cannot produce. Omega-3 and omega-6 have numerous roles in our body, for instance, they help regulate inflammation and blood lipids while also being a key structural component of cells.
Current dietary guidelines recommend limiting saturated fat intake. The reason for this is because, across numerous population-wide studies, a higher saturated fat intake has consistently shown to increase CVD risk compared to a lower saturated fat intake. Why? Well, saturated fat increases circulating LDL-C concentrations, which in turn increases the risk of CVD.
Remember, saturated fat is found in foods, and not all foods high in saturated fat will increase your risk of CVD. If we were to avoid foods that contain an undesirable nutrient, then there really wouldn't be much food left to choose from! Regular consumption of high saturated fat foods including fatty cuts of meat, butter, coconut milk and processed foods will produce these unwanted effects. Yet, other foods high in saturated fat such as cocoa and some dairy products like Greek yoghurt do not - this is likely down to other beneficial nutrients which stop or inhibit the action of saturated fat.
Finally, trans fats, arguably the least contentious type of fat. It is widely accepted that trans fats should be avoided as much as possible. These are found in highly processed foods as they provide a desirable texture and taste, yet produce undesirable health effects such as reducing 'good' HDL-C, and increasing 'bad' LDL cholesterol. Trans fats have also been associated with numerous other health outcomes, and therefore should be restricted as much as possible.
I hope this has explained in a little more detail the different types of fat found in food, and why not all fat is good or bad. Fat is an essential nutrient, but there are types of fat which we should aim to preferentially consume, and types of foods that contain different fats we should preferentially consume too!
Joseph specialises in appetite regulation, weight loss and personalised nutrition. He is our associate nutritionist with the AfN & also works as a health coach looking at lifestyle factors that influence eating behaviours. Contact us to request Joe's expertise.