Why a Low Fat Diet May Not Be The Answer

Are commercially produced low fat, diet food products make us miserable and tricking us into over-eating?

Our consumption of processed food has rocketed in the last 30 years. Our grandparents ate very differently to the way that we eat now. As our lives have become busier, our free time has decreased and convenience foods have become readily available.

At the same time, our waistlines have been steadily expanding. The UK and the US have some of the highest obesity levels in the world. In 2013, approximately 25% of the UK population were obese; and 41% of men and 33% of women in the UK were overweight1. Projections suggest that if the current rate continues, by 2030, half of the UK population could be obese2.

obesity 1500

Processed, low fat diet foods are not what they seem

Since the weight-loss industry exploded onto the UK food scene, companies such as Weight Watchers (founded 1963) and SlimFast (founded 1977) have made millions by producing special low fat diet products that we have eaten in the belief that they will help to make us thinner, healthier and happier. In fact it is now apparent that the fat in ‘fat-free’ or ‘low-fat’ products has been replaced with sugar, preservatives and/or artificial sweeteners, which are used to make the food more palatable.

What happens when we go on a low fat diet?

Many people who follow calorie restriction, low fat diets or eat processed ‘diet foods’ lose weight, at first. Eating too few calories is an effective way of losing weight. If you eat too few calories however you are also likely to be hungry, as well as suffering from food cravings, headaches and lethargy.

Unfortunately, as soon as you stop your low fat diet and start eating the way you used to – which most people do – the weight comes piling back on. As a result you go back to the diet that worked for you first time around and start the whole process again. And the depressing cycle continues, for some people in a seemingly never-ending loop of diet highs and lows, binges and fasts, weight loss and weight gain.

The effect of processed, low fat diet food on the body

Processed low calorie, low fat diet foods often contain added sugar and/or artificial sweeteners. Research has shown that sugar effects the brain in a manner similar to drugs of abuse in that it causes an increase in dopamine release3. This suggests that sugar can in fact be addictive, the more sugar you eat, the more you crave it. Research into artificial sweeteners such as saccharin suggests that this substance could have a similar or more intense effect on the brain, causing this artificial substance to be more addictive than cocaine4.


What’s more, sugar does not appear to stimulate satiety signals in the brain, meaning that you do not receive feelings of being full.

Fat cells produce a hormone called leptin, which signals our brain to tell us when to stop eating i.e. it tells us that we are full. Evidence shows that when we eat too much sugar, the resulting insulin imbalance causes leptin resistance5. Most obese individuals have high leptin levels but are leptin resistant6.

In people who are leptin resistant, the brain does not receive that crucial leptin signal that tells us to stop eating.

The addictive nature of sugar and sweeteners in processed diet food products means that perversely, the more ‘diet’ foods we consume, the more we crave sweet foods. This combined with the lack of ‘fullness’, (the lack of satiety signals received by the brain), means that we are actually more likely to overeat when on a diet and eating processed low fat diet food products.

Our whole food beliefs

farmers market fruit and ve

Low-fat and fat-free food products are not the answer to weight loss or good health. The answer lies in simply eating whole, unprocessed food with no refined sugar, no white flour and no processed vegetable oils. Eating plenty of good food – containing a balance of fat, protein and carbohydrate – at regular intervals, helps to prevent you from suffering cravings and food binges.

Could you go for 28 days without eating any added refined sugars, alcohol or white flour? If you are ready to change your relationship with food, then The Green Apple Club can help you to learn the good habits that will prevent you from ever having to go on a low fat diet again!

Join The Green Apple Club



  1. http://www.hscic.gov.uk/catalogue/PUB16988/obes-phys-acti-diet-eng-2015.pdf
  2. http://www.nhs.uk/news/2011/08August/Pages/half-of-uk-predicted-to-be-obese-by-2030.aspx
  3. http://www.sciencedirect.com/science/article/pii/S0306452205004288
  4. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1931610/?tool=pubmed
  5. http://www.ncbi.nlm.nih.gov/pubmed/15314628
  6. http://onlinelibrary.wiley.com/doi/10.1038/oby.2009.228/pdf


About the author: 

Sonia Nicholas is a Biomedical Scientist and Freelance Clinical Science Writer & Editor. She has been working in the field of clinical science for fifteen years.

Sonia believes that everyone can improve their health by eating a clean diet – a claim that scientific research increasingly supports. Sonia also believes that healthy, clean eating is accessible to all and doesn’t have to be an expensive lifestyle choice.

All of the articles on The Green Apple Club website are evidence based and fully scientifically referenced.

Related reading:

ARTICLE: Portion Sizes: Building a Healthy Plate of Food
ARTICLE: Clean-Eating, Carbs and Weight Loss
BLOG: Its Time to Stop Dieting – Eat More to Lose Weight

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