Our body turns excess calories into fat, i.e. overweight.

Our organism needs an average of 2 000 -- 3 000 calories daily -- women and children less, and men need more. But, these values depend on many factors.

The number of calories for every individual can be precisely determined with the Harris-Benedict equation which gives different results depending on the gender, age, height and activity, by calculating the Basal Metabolic Rate (BMR).

Calculate the optimal number of calories you should enter daily using the following equation:

Men:
BMR = 66 + 13,7 x weight in kg + 5 x height in cm -- 6.8 x age in years

Women:
BMR = 655 + 9.6 x weight in kg + 1.8 x height in cm -- 4.7 x age in years

Then, multiply the number you get with the lifestyle factor

• Minimal physical activity -- multiply BMR by 1.2
• Poorly active life (1-2 times a week workout) multiply BMR by 1,375
• Moderately active lifestyle (3-5 times a week workout) multiply BMR by 1.55
•  Particularly active life (6-7 times a week workout) multiply BMR by 1,725
• Extremely active life with regular and intense physical effort -- multiply BMR multiplied by 1.9

This shows that individuals who have extremely active life (have any kind of physical activity 2 times a day) can consume around 50% more calories than those who do not any kind of sport.

For example, a physically inactive man aged 50, who is 185cm tall and weighs 90kg, should enter just 2 220 calories daily to avoid gaining weight. If this man eats one and a half medium-sized pizza, which has approximately 3 000 calories, he should swim for an hour to get rid of the excess calories.

In addition to this, you should have in mind that latest researches also show that fruit and vegetables not only contain less calories, but these food products are immensely rich in numerous nutrients, which change intestinal flora and enhance the fat burning process.