# How do I calculate the number of calories I should eat to lose weight?

Calorie restriction is one of the first steps towards weight loss. But how many calories per day should we not exceed to lose weight?

To function, the human body needs the energy provided by the food we eat. But if we eat more than our body needs, we gain weight. Conversely, if we eat less, we lose weight. However, the number of calories needed for each varies. For example, a sedentary person spends fewer calories than a great athlete. Before knowing how many calories to eat to lose weight, you have to know how many calories our body needs to function on a daily basis and ensure its vital functions such as digestion and maintaining body temperature. This is called basal metabolism.

## Calculate your basal metabolic rate to lose weight

To calculate this metabolism, the formula of J. Arthur Harris and Francis G. Benedict can be used. For men, the formula is: 13.751 6∗weight (kg) + 500.33∗height (m) −6.755 0∗age (year) + 66.473; for women, the formula is: 9.563 4∗ weight (kg) + 184.96∗ height (m) − 4.675 6∗ age (year) + 655.095 5.

However, only people between 151 and 201 cm tall, with a weight between 25 and 124.9 kg and an age between 21 and 70 years old can use this formula. Elderly and overweight people can use the following formulas, from Black et al. : MB (male) = 259∗weight (kg)^0.48∗height (m)^0.50∗age (year)^−0.13; MB (female) = 230∗weight (kg)^0.48∗height (m)^0.50∗age (year)^−0.13.

## Combine caloric restriction and sport to lose weight

In addition to knowing your basal metabolic rate, you should take into account the physical activity you do every day to calculate the number of calories to respect to lose weight. The known basic metabolic rate will then be multiplied by a coefficient which varies according to the level of physical activity practiced. For sedentary people, this coefficient is 1.3. It then increases to 1.375; 1.55; 1.725; up to 1.9 if the person concerned does a lot of sport. With these two calculations, we can then compare the calories we absorb and the calories we need. To lose weight, it will be enough to reduce the number of calories absorbed by 10 to 15% below the calories necessary to maintain the basic metabolism, which will force the body to draw on its reserves. But it will also be necessary to ensure that you consume good calories from healthy foods.