Why just counting calories doesn't work

Obesity has historically been viewed as a disorder resulting from an energy imbalance – simply put – if you consume more calories than you expend then you gain weight and if you eat fewer calories then you lose weight. 

Most people who are trying to lose weight believe that if they exercise more and eat less then their efforts will ultimately be successful. Unfortunately, this is rarely the case for sustained weight loss with most people regaining any weight lost (and often more) over time.

New research has been published that suggests the belief that “moving more and eating less” is actually wrong and the oversimplification of the “calories in-calories-out” model ignores the fact that the quality of the nutrition contained in the calories eaten is the key.

The paper, published in the AJCN argues that successful weight loss and weight maintenance is much more about WHAT you eat rather than HOW MUCH you eat.

The weight loss is directly related to our hormonal response to the food eaten and these hormonal changes are the primary driver for excess fat storage. 

When high glycaemic load (GL) foods are eaten (usually refined carbohydrates that cause a rapid increase in blood sugar), the body responds via 2 hormones. Firstly, by increasing its production of insulin. This causes the body to take this raised blood sugar into its cells and convert it into fat; secondly by suppressing production of glucagon. This hormone helps to restore blood sugar levels when these drop. These 2 hormonal changes effectively prime the body for fat storage. There is a rapid rise and fall in blood sugar as a direct consequence – which then, when detected by the brain, sends a signal to the body to eat more. At the same time, the body, in its efforts to conserve the available blood sugar, will slow the metabolism.

So, instead of focusing on the energy balance model, the authors advocate a shift in focus to a carbohydrate-insulin model. If hunger can be reduced and the production of insulin controlled, then sustainable weight loss is possible. Carbohydrate has been shown to be the main macronutrient that impacts on insulin production. Lower carbohydrate diets have been shown to reduce appetite, as well as limiting the hormonal responses of insulin and glucagon. This all occurs in the absence of calorie counting or trying to eat less.

By changing our approach to diets and focusing on the quality of calories rather than the quantity, we can exert some control over the hormonal changes that drive us to eat to excess. Some recommendations include:

  1. Eating more fibre rich foods. This delays the stomach emptying and also increases satiety. Typical foods include unrefined carbohydrates such as vegetables, beans, legumes, pulses, whole grains, nuts and seeds. Whole foods are preferable to fibre supplements.
  2. Focus on lean protein and healthy fats. Protein and fat have little impact on blood sugar so this will remove the blood sugar spikes that drive insulin release.
  3. Reduce consumption of Ultra-processed foods. These foods are considered to be highly palatable – usually lacking nutrients and often found in snack foods. These foods have been created in the laboratory to limit our ability to feel hunger and increase our desire to eat more. Crisps/ biscuits/ cakes and fast foods are typical examples.
  4. Reduce sugar consumption. Excess sugar consumption has one of the biggest impacts on insulin and this quickly leads to hunger and cravings for more. If instead, you can satisfy your sweet tooth with some fruit, preferably the whole fruit rather than juice, then the presence of the fibre contained will slow down the blood sugar response. Look out for added sugar sources such as fizzy sugary drinks, sweetened cereals, cakes and pastries.
  5. Practice more mindful eating. Paying attention to those hunger cues and asking if you really are hungry or maybe just bored or stressed. Also avoid eating whilst doing something else such as watching TV or playing on devices – all things that can distract you from focusing on what you are actually eating, and therefore may not recognise immediately that you are full.
  6. Pay attention to your sleep. If you get less than 7-9 hours restful sleep on a regular basis this can play havoc with your hunger hormones making you more hungry for snack type food and less satisfied when eating it – thus being sleep deprived can make you consume a lot more unhealthy calories.

When you consider the serious health implications of insulin resistance, fatty liver disease and T2D and appreciate that a lower carbohydrate diet as outlined above can provide positive health outcomes, it makes sense to consider an alternative model to tackling obesity.

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