The Science Behind Counting Calories

Counting calories is one of the oldest enduring tips in dieting. The myth of ‘calories in’ versus ‘calories out’ just won’t go away. There’s no denying that calories are a part of the picture but the conventional weight loss idea puts way too much emphasis on the importance of energy (or calories).

So often I do assessments on people’s lifestyle and nutrition and find that they are vitamin and mineral deficient. Their body is in a state of crisis, they are loaded with toxins and have ground their metabolisms down. We should be shifting more of the focus on consuming a nutrient rich diet, instead of counting calories. This is because if your body is in a healthy and balanced state, you will naturally feel full and refrain from over consuming.

The math of counting calories

Let’s take fats for example – the calorie theory states that 454 grams of fat contain 3,500kcal of energy. Therefore, to lose 454 grams of fat you simply need to eat 3,500 fewer calories. Full stop. However, it’s actually not that simple. 

First, calories are not an exact number. These are general values expressed across entire food groups. Second, and more importantly, human basal metabolic rates (calorie expenditure) are all predictions. The only way to measure exact basal metabolic rates (BMR) is with a gas analysis machine. To use a weight and height formula to accurately estimate the energy output of a human cell is never going to be exact. Two people could be the same height and weight but are made up of a totally different composition and possesses extremely different metabolisms.

Let’s face it, the whole premise of counting calories is to reduce consumption by a few hundred calories to lose weight. What if the formula produces a number that is a couple hundred calories less than what you were expecting to lose?

The biology

Let’s forget about the glaring issues regarding energy values for a minute and observe how the body responds to a reduced calorie intake. Your body can’t really tell when you’re attempting a new diet. In the event of a dramatic reduction of calorie intake, it is compelled to believe that you are stranded on a desert island without any food. As a result, it tries to look after you – to survive.

Your body is now in survival mode when you work on a calorie deficit, so it needs to “discard’ the part of you that uses the most energy. This is referred to as the lean muscle. Your body hangs on to the fats as long as possible because, a) it uses up less energy, and b) because it is going to be a valuable reserve if you are ‘stranded’ for a long time.

Our bodies are programmed for survival. Weight can reduce quite rapidly to begin with, but then our bodies adjust to the food deprivation and reduced calorie intake. We then lose lean muscle, store fat, and slow down metabolism dramatically. Our body’s ability to survive, especially in the short term, will always prevail.

Francis Benedict, in 1917, was the first person credited for conducting calorie deficit experiments. Research has shown that Francis Benedict’s study, and every subsequent study about calorie deficit has revealed that “some weight loss is accompanied by intense hunger and tiredness with an overwhelming desire to want to eat more and do less”. These studies show that “weight loss has never matched the 3,500 formula – over even a short period of time. It has never even come close and weight regain had been observed every time,” comments Zoe Harcombe, one of the UK’s leading dieticians.

Harcombe’s research points to the The Minnesota Starvation Experiment in 1945 as being the definitive study. “36 men were put on a 1,500-1,600 calorie a day diet with a moderate walk scheduled each day. They lost a fraction of the weight that the 3,500 formula would have predicted. The men turned into hungry, miserable, food-obsessed shadows of their former selves. Within six months, researchers found it increasingly difficult to induce further weight loss, even dropping calorie intake to around 1,000 calories a day. Some men started regaining at a calorie level that should have seen them continuing to lose weight. Within weeks of the conclusion of the experiment, the men had regained all weight loss, plus about 10%” states Harcombe. Does this resonate with anyone?

Unsubstantiated theory

The numbers make sense but our body is simply not a number cruncher! Ms. Harcombe asked the British government and health authorities to explain the theory and the responses are amazing:

The British Dietetic Association commented that they do not hold information on the topic. Likewise, the National Obesity Forum didn’t know anything either, yet they quote the 3,500 formula on their website. The Department of Health responded that they are “unaware of the rationale behind the weight formula”.  The National Institute for Clinical Excellence also could not explain the rationale of this conventionally accepted myth. The key advocates of the calorie formula, The Dietitians in Obesity Management states, “The key to all of this is that weight loss doesn’t appear to be linear, any more than weight gain is.”

Now if this doesn’t prove that the calorie formula is an unsubstantiated myth, I don’t know what will. No leading agency has any idea where this founding piece of diet advice comes from or what supports its validity, yet it’s in all their literature!

The fact is that there is almost a century’s worth of crushing evidence that the counting calories theory doesn’t work. But our society holds on to it for dear life. The mantra of “do more, eat less” for weight loss seems to be only making society fatter. It’s time for a recount, more crucially to start counting more important dietary elements.