Understanding the calorie deficit to lose weight

For many women and men, losing weight is often a frustrating challenge. Especially since so many myths and magic solutions abound on the Internet, and we no longer know which saint to dedicate to! However, the keystone of any slimming diet is the caloric deficit. However, if calorie reduction is essential for weight loss, it is useless, even dangerous, to reduce intake too much, at the risk of causing diseases and deficiencies.

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All about calories

In dietetics and slimming nutrition, a term that often comes up is calorie, which is used to measure the energy provided to the body by food ingested at a given time. Quantifying the calories contained in the diet is essential because it tells us about the amount of energy received by the body to support physical exertion. However, no need to hunt them down to the point of obsession, because already, not all calories are equal.

Composed of carbohydrates, fats or proteins, calories have a different effect on the body, depending on whether they come from carbohydrates, fats or proteins. Therefore, the amount of calories you ingest is less important than the type of calories. For example, not all calories from carbohydrates are created equal: some are useful while others are particularly harmful. Indeed, carbohydrates themselves do not offer enough noticeable nutritional benefit for the body. They rarely contain fiber, which speeds up their treatment and thus causes a harmful increase in blood sugar. On the other hand, only a minority of carbohydrates contain fiber: processed more slowly by the body, these carbohydrates make it possible to stay full longer.

For their part, proteins and fats work on the same principle and are complementary. For example, the lean protein in white meat (chicken or fish) contains the same amount of protein and healthy fats, allowing the body to burn most of the calories to turn them into energy, rather than accumulating them.

What is the calorie deficit?

Calorie deficit is usually the technique that is first thought of as part of a slimming program. This reaction occurs when the calories burned out outnumber the calories absorbed by the body. For example, if you burn 2,000 calories during a fitness session but only consume 1,500, it creates a deficit of 500 calories.

But it is still necessary to know that the caloric deficit is not an exact science, the ideal method to reach the deficit depends on each individual. That's why you must first calculate your basal metabolic rate, which is the minimum amount of energy your body will need to survive, including during rest. There are several ways to calculate the basal metabolic rate, but the Mifflin – St Jeor formula is particularly suitable for calculating the calorie deficit:

Male = (10 x weight in kg) + (6.25 x height in cm) – (5 x age) + 5
Female = (10 x weight in kg) + (6.25 x height in cm) – (5 x age) – 161

For example, for a 28-year-old man, measuring 188 cm for a body weight of 105 kg, it can be said that his basal metabolic rate is calculated as follows:

TMB = (10 x 105) + (6.25 x 188) – (5 x 28) = 2,090 calories

For a 30-year-old woman, measuring 164 cm and weighing 85 kg, the calculation is as follows:

TMB = (10 x 85) + (6.5 x 164) – (5 x 30) – 161 = 1,570 calories

Calorie deficit: how does it work?

As you would have understood, in the field of weight loss, it's all about balance. That's why calculating your basal metabolic rate (the amount of calories required by the body) is essential to know your ideal calorie deficit. Indeed, when your calorie intake is equal to your TMB, your weight will remain stable. On the other hand, there is an imbalance when the energy intake is lower than the TMB (weight loss), as well as when the energy intake is higher than the energy need (weight gain).

For weight loss to be effective and sustainable, it is estimated that it is necessary to cause an energy deficit of the order of 10 to 15% of the TMB. But be careful, the calorie deficit should not be excessive because it could lead to nutritional deficiencies. Especially since below a certain amount of calories, the body reacts by saving energy and storing larger amounts of calories. This results in a yo-yo effect that would complicate the weight loss process.

Finally, some studies show that the calorie deficit is not enough to induce effective weight loss. On the contrary, this process, when not carried out correctly, could even prove harmful to the body. Indeed, our body does not only ingest calories but especially nutrients, while a caloric restriction could reduce the consumption of nutrients essential to the functioning of cells.

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