Why Fad Diets are unsuccessful!

Fad diets

In my many years of working as a dietician and few years as a medical doctor, I have witnessed many frustrated patients experience the ineffectiveness and detrimental outcomes of fad diets. Below, is a summary of my experience with and insights into fad diets and the reasons for their poor success.

1. Fad diets use a “one approach fits all” based on the assumption that all individuals are identical i.e. identical genetics, digestion and metabolism. Fad diets lack personalisation in that they do not cater for individual likes, dislikes and unique physiologies.

2. Fad diets are not holistic – they often do not incorporate psychotherapy and physical activity.

3. Fad diets are often very restrictive and are not sustainable in the long run.

4. The psychology of fad diets sets us up for long term failure.

Fad diets promote short term goals and short term thinking. In a world of instant gratification where our lives have become consumed by such, our brain wiring changes and it becomes more difficult for us to establish long term meaningful pursuits and goals such as improving overall health, wellbeing and longevity.

This short term approach teaches us to follow a specific set of rules for a specific period of time. It teaches us that once the diet has finished and our short term goals have been achieved, the rules can be relaxed and that’s when we slip back into our old habits.

Fad diets operate on the premise “No pain, no gain”. Ponder on this viewpoint for a moment. Your brain is led to believe that dieting is associated with deprivation, sacrifice and suffering (i.e. some element of pain or discomfort).

Experiments have shown that people will do more to avoid pain than they will do to gain pleasure. The only reason people are compliant in following fad diets is because they use immense short term willpower to override their  feelings of deprivation +/- pain. But this willpower never lasts and we eventually fall prey to the same old persisting belief that dieting is associated with deprivation, sacrifice and an element of pain and suffering. Hence, we fall back into the comfort of old habits and end up with more weight than when we started the journey.

5. Serial Fad diets often result in a yo-yo effect.

Yo-yo dieting, also known as “weight cycling,” describes the repeated pattern of losing weight, regaining it and then dieting and losing weight again only to regain more weight than when we started dieting.

The problem extends beyond gaining weight with time. With weight cycling, fat is regained more easily and muscle mass is lost over time resulting in a higher body fat percentage, decreased physical strength and decreased exercise tolerance.

Weight gain and especially weight cycling has been associated with increased risk of heart disease and possibly type 2 diabetes. The greater the change in weight, the greater the risk. Weight gain, including rebound weight gain in yo-yo dieting, also increases blood pressure.


Before embarking on a “diet” use the below checklist to ensure that the “diet” is safe, effective and the real deal:

  • The diet should be realistic and sustainable.
  • The diet should be based on long term achievable goals.
  • Long term goals should be multi-faceted. Weight loss or optimisation should not be your only goal. Goals should  also include optimisation of overall health and wellbeing – physically, mentally and spiritually.
  • If weight loss is a goal, it should not exceed 1lb – 2 lb per week.
  • The diet needs to be individualised and cater for likes, dislikes and unique physiologies.
  • A safe and effective diet should never leave one feeling hungry.
  • Ideally, the diet needs to be accompanied by psychotherapy. For example, conditioning the mind into associating new dietary changes with pleasure and linking old behaviours with pain. This is where a health coach can be beneficial.
  • The diet needs to consider other lifestyle changes such as increased physical activity, quitting smoking and reducing or cutting out alcohol.

I trust this blog has motivated you to embark on a new journey of health and positive lifestyle changes.

Written by Corrinne Rae Giles (Dietician and Medical Doctor).

Leave a Reply

Select your currency
GBP Pound sterling
EUR Euro