I am not saying that calories in vs. calories out does not influence changes in body weight. What I am saying is that the process of purely reducing the number of calories you are allowed to eat each day is an inefficient way to get healthy and look better. It also has an extremely poor long-term success rate. In fact, a review of 31 studies looking at calorie restriction and weight loss in The American Psychologist found that as many as two thirds of dieters weighed more following their diet than they did at baseline! With a failure rate this high, why do people persist with this method?!
There are many reasons for this poor success rate. In this article I hope to explain a few of them. In my opinion, the primary reason these diets fail is because lowering calories lowers our metabolic rate. Eating less calories causes levels of certain hormones to drop (including testosterone, grehlin and thyroid hormones) and results in less calories burnt through the thermic effect of feeding. This all adds up to make us feel hungry and lethargic and predisposes us to gain fat as soon as we start eating a normal amount of food again! This is essentially what is going on with “yo-yo” dieters.
Purely cutting calories does not take into account the influence of the different macronutrients (protein, fat and carbohydrate). These different macronutrients have very different effects on our hormones and influence our metabolic rate (the amount of energy we burn at rest). For example, when we eat a diet high in carbohydrates, our bodies release higher levels of the hormone insulin. The presence of insulin puts us in a state of energy storage rather than energy mobilisation, so our bodies are receiving no signals to breakdown fat for energy. Looking now at metabolic rate, a diet high in protein has been shown to significantly increase the energy we burn at rest due to the thermic effect of feeding.
Another key critique of the calorie restriction diet is the effect it can have on eating patterns. When a person has a set allowance for calories for a given day, they have a tendency to save up their allowance in order to binge on things like chocolate and alcohol without failing their diet. It does not take a genius to realise that this is not conducive to healthy fat loss. Additionally, eating in this manner does not lend itself to maintaining stable blood sugar and appetite levels. It is much more difficult to make healthy choices when the hormones that regulate your appetite are all over the place.
If you are looking for a nutritional strategy that will enable you to lose body fat in a healthy manner and maintain that loss, purely cutting calories is probably not your best bet. Keep reading our blog for future posts detailing more effective strategies that can help you produce sustainable results.