The Low Down on Fats
Fats are a very misunderstood food group, which may be in part to the amount of mixed data published around the effects of fat on our health. Many years ago, scientists linked fat intakes around the world to rates of cardiovascular deaths, and this is where much of the scaremongering about fats is rooted from. What we are seeing today are the effects of this fat scaremongering, and consequently higher intakes of processed carbohydrates and sugars instead.
It’s really important before we go any further to highlight that a lot of the foods know as ‘fatty foods’ such as cakes, biscuits, ice cream, pastries, deep fried foods, pizzas and chips, are also high in processed and refined carbohydrates and sugars. Therefore, we must look at the foods we eat in their entirety, and in context with the rest of the diet.
Fats represent a whole food group, with different types of fat within in, but often fats are labelled as all good or all bad, leading to many of the beneficial fats being left out from the diet.
The bottom line is, we need fats within the diet for so many reasons. There are different types of fat, and ones which are more beneficial for our health, which will be outlined in this article.
Why do we to eat fats?
- They make up about 60% of our brain, so they are vital for optimal brain health and functioning
- Fats are the building blocks for our hormone production, such as oestrogen, progesterone and testosterone
- They are a major source of energy, containing 9 calories per gram
- Fats form the structure of the cell walls within our body
- They help us absorb our fat-soluble vitamins (Vitamins A, D, E & K)
- Fats help with muscle movement and fluidity of our joints
- Certain types of fat perform anti-inflammatory actions within the body
- Fat helps protect our internal organs and keep us insulted
- Fats help slow down to rate at which our sugars are digested and released into the blood stream and help keep us full after a meal
So why does fat get so confused?
Fat is one of the three macro-nutrients; the three food groups we need to the largest quantities. As mentioned above, fat does contain 9 calories per gram, compared to protein and carbohydrates which contain 4 calories per gram. So, for this reason, for many people with weight loss goals in mind, it seems to make most sense to leave behind the foods which contain more calories, because eating less calories leads to weight loss, right?
Well, being in a calorie deficit (consuming less calories than you use up in any given day) is an aspect to consider for weight management, but there are so many other pieces to the puzzle, such as stress, sleep and the balance of the different food groups within the overall diet. For many female clients that I see, they start to suffer with all kinds of hormonal imbalances as a result of following a fat restricted diet for a prolonged period of time.
Are all fats the same?
No, we have different types of dietary fat which can have different effects within the body.
Saturated and unsaturated and the two main different types of fat, but each has further sub-groups.
Saturated fats are those which tend to come from animal sources and are solid at room temperature, such as butter, lard, ghee, cheese and milk, coconut oil and fat found on meats and poultry. The word saturated is referring to the chemical structure, where all carbon atoms are hold as many hydrogen atoms as they can. Generally, saturated fats shouldn’t make up more than about 10% of our daily caloric intake, as in high amounts they can contribute to higher levels of our LDL cholesterol (know as a ‘bad’ cholesterol). The notion of high intakes of saturated fats leading to increased risk of death from cardiovascular disease is one that has been investigated further, and the data shows that there is not enough good quality evidence to suggest this direct link, but it is recommended to replace some of our saturated fats with unsaturated fats to reduce the risk of cardiovascular disease. Interesting studies have also recently showed that replacing saturated fats with processed carbohydrates does not reduce risks of developing heart disease.
Trans fats are produced as a by-product of dehydrogenation, a process that is used to turn oils into solids, such as producing sunflower margarine, to prevent them becoming rancid. There is no known safe level for the consumption of trans fats, and these could be harmful to our health, and are banned in the US. Trans fats within the diet may cause inflammation, increases in LDL cholesterol and increased risk of heart disease.
Unsaturated fats have fewer hydrogen atoms attached to their carbon chains and therefore, oils are usually liquid at room temperature. The main two sub-groups of unsaturated fats are monounsaturated fats and polyunsaturated fats, although certain foods contain a mixture of mono, poly and saturated fats.
Monounsaturated fats include olive oil, peanut oil, canola oil, avocado and most nuts.
Polyunsaturated fats are known as essential fats, meaning our body doesn’t produce them, so they must come from out diet. Our polyunsaturated fats (known as PUFAs) are required for blood clotting, muscle movement and involved in inflammatory pathways. The two main types of PUFA are omega-3 and omega-6 fatty acids.
Omega 3 fats are mainly found in two forms, EPA and DHA. These are known to have anti-inflammatory properties, beneficial to brain health and development and protective to the heart. Sources of omega-3 include fatty fish (salmon, mackerel, trout, herring, sardines, herring, anchovies), walnuts, flaxseed and chia seeds. The later 3 are from plant-based sources, so they contain the precursor to EPA and DHA, known as ALA. The conversion of ALA to EPA and DHA is fairly low, around 5%, so you would need to consume a lot more of these plant-based sources to obtain the same amount that you can get from fish.
Omega-6 fats are still essential in the diet, and it’s important to try and get a good balance of omega 3 and omega 6 fats, as it’s easy for this balance to become more omega-6 dominant when consuming lots of processed foods. Sources of omega-6 fats include vegetables oils such as corn oil, soybean oil, poultry, eggs and some nuts. When the omega-3 and omega-6 balance is out of whack, this can lead to states of inflammation. The best way to ensure a good balance is to minimise your intake of processed foods and focus on whole foods.
In summary, fats are vital for many body functions, and should be included in the diet daily. We should not be fearful of fats, but rather be educated on healthy sources and know what foods to find them in. Rather than looking at food groups in isolation, we need to look at the whole diet and focus more on getting the right balance between our carbohydrates, proteins and fats.
As a general guideline, we should we looking to add a source of healthy unsaturated fats to all main meals. A thumb-sized portion is a handy tip to remember. This may be a drizzle of oil, a sprinkle of seeds or some avocado added to a meal.
*** This blog post is not intended or implied to be a substitute for seeking professional medical advice, medications, diagnosis or treatment. Information provided here is general and is not intended to treat, diagnose, prevent or cure any diseases or conditions. Please contact your GP or private health consultant if you have any personal health concerns or consult a registered nutritional therapist for personalised dietary and lifestyle advice and guidance.