Low fat vs full fat foods

Low fat products have long been promoted as weight loss miracles. Full fat products, on the other hand, have been demonised by popular media over the years as being ‘unhealthy’, ‘too high in calories’ and ‘fattening.’ But is this really true?

Low fat products

Reducing the overall fat content in foods is done by manufacturers in an attempt to make products ‘healthier’. However, to mimic the pleasant taste and texture of full fat foods, manufacturers often have to increase the amount of sugar and other ingredients in low fat products. This is especially worrying for those following a low carb lifestyle. This also means that some of the calories from fat that are taken out of the product are put back in, in the form of sugar.

Trans-fats

It is also worth mentioning trans-fats. Small amounts of trans-fats are found naturally in some foods such as meat and dairy – these are not the problem due to the small quantity present. But high amounts of trans-fats found in some processed foods are known to be harmful because they raise unhealthy LDL cholesterol and reduce healthy HDL cholesterol levels.

Full fat products

Fat is extremely important in the diet for a number of reasons. Fat provides more calories per gram than protein and carbohydrate, making it a large source of energy for the body. This is especially true on a low carb lifestyle as the body will be using fat, and not carbohydrates, for fuel.

Some people worry about fat being high in calories, but full fat products are rich and highly satiating, making it difficult to eat too much of them. Fats are also excellent at keeping hunger at bay for longer than carbohydrates and low fat products.

Fat is also important for nutrient absorption – Vitamins A, D, E and K are fat soluble; this means that they can only be absorbed from foods when fat is present. So not eating enough fat may lead to malnutrition.

Dietary fat is also the source of essential fatty acids, which are important for health. The two essential fatty acids are omega-3 and omega-6. These fatty acids are polyunsaturated fats and have been shown to be beneficial to heart health, immunity and brain function. Monounsaturated fats have also been shown to improve heart health.

Interestingly, there have been a number of studies which show that replacing some saturated fats in the diet with refined carbohydrate and sugar leads to no improvement or a greater risk of cardiovascular disease (CVD). These studies also found that replacing some saturated fats with polyunsaturated and monounsaturated fats resulted in a lesser risk of CVD [1,2,3]. Saturated fats themselves have had their harmful effects questioned in recent years. Several meta-analyses (reviews of lots of other studies) found that there was no significant association between saturated fat intake and heart disease [4,5,6].

The take home message

• Low fat products can be higher in sugar and may contain trans-fats, both of which are known to be unhealthy.
• Low fat products are less satiating than full fat products so it can be easy to eat a lot more of them.
• Fat is an important nutrient and has many functions in the body, including vitamin absorption, heart health and brain function.
• It is best to get dietary fat from a range of naturally high fat foods such as eggs, oily fish, dairy, nuts and seeds to avoid trans-fats.

Discover more reasons to swap low fat for full fat when you join the Low Carb Program.

References

[1] Siri-Tarino, P. et al. (2015). Saturated Fats Versus Polyunsaturated Fats Versus Carbohydrates for Cardiovascular Disease Prevention and Treatment. Annual Reviews of Nutrition, 35. DOI:  10.1146/annurev-nutr-071714-034449

[2] Givens, D (2017). Saturated fats, dairy foods and health: A curious paradox? Nutrition Bulletin, 42. DOI: 10.1111/nbu.12283

[3] Yanping, L. et al. (2015). Saturated Fats Compared With Unsaturated Fats and Sources of Carbohydrates in Relation to Risk of Coronary Heart Disease. Journal of the American College of Cardiology, 66(14). DOI: 10.1016/j.jacc.2015.07.055

[4] Siri-Tarino, P. et al. (2010). Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. American Journal of Clinical Nutrition, 91(3). DOI: 10.3945/ajcn.2009.27725

[5] Astrup, A. et al. (2011). The role of reducing intakes of saturated fat in the prevention of cardiovascular disease: where does the evidence stand in 2010? American Journal of Clinical Nutrition, 93(4). DOI: 10.3945/ajcn.110.004622

[6] Chowdhury, R. et al. (2014). Association of Dietary, Circulating and Supplement Fatty Acids With Coronary Risk: A Systematic Review and Meta-analysis. Annals of Internal Medicine, 160(6). DOI: 10.7326/M13-1788

[7] British Nutrition Foundation. (2018). Fat. [online] Available at: https://www.nutrition.org.uk/nutritionscience/nutrients-food-and-ingredients/fat.html?limitstart=0

[8] Freer, A. (2015). Cook. Nourish. Glow. Penguin Random House: UK.

[9] Torrens, K. (2016). The truth about low-fat foods. [online] Available at: https://www.bbcgoodfood.com/howto/guide/truth-about-low-fat-foods