Energy provided by food is limited mostly by digestion. The main nutrients required by the human body come from 5 separate classes:
Approximately 1600 – 1800 kcal are needed daily by a man adult, while a woman needs 1200 – 1400 kcal. The need for energy is different from person to person, depending mainly on the life style, so the energy provided by food is used differently from person to person. For example, active men need approximately 3000 kcal daily, active women need 2500 kcal, while athletes usually need more than 5000 kcal per day.
Any surplus of calories is transformed and stocked as fat by the human body. 1 kg of fat is the equivalent of 7000 kcal of stocked energy.
Every time a person burns 7000 kcal more than he accumulates, he loses 1 kg of fat. For example, if you can burn with 1000 kcal per day more than the energy provided by food daily, you can get rid of 1 kg of fat in a week.
DO NOT FORGET that 1 kg of fat means actually 1.4 kg of adipose tissue because this contains, besides fat, water and other elements. Still, fat is an important element that must always be present in the human body. Women need four times more fat then men do (the minimum quantity of fat required by the human body is 13% for women and only 3% for men).
Usually, a 20 – 30 years old man has 15 – 18% fat in his body, while a woman of the same age has 25 – 28%. When dieting, sometimes less body weight means less fat and less muscles (mainly when the diet is unbalanced or is not suitable for that person). So, in this case the end of the diet means more fat, but less muscles.
Generally, breakfast and lunch must contain 600 kcal each and dinner must contain about 300 kcal. Breakfast should usually contain food rich in carbohydrates (like milk, cereals, etc.). Lunch should have 50% carbohydrates and 50% proteins (like eggs, fish, rise, chicken, pasta, etc.). Also, is recommended no to eat later than 8 o’clock PM. As mentioned before, exercises are the most effective and safe ways of burning calories, especially when dieting.
Here are some examples of activities that lead to burning of 100 kcal:
Swimming or cycling for 12 – 15 minutes
Playing football for 15 minutes
Walking for 25 minutes
Running for 10 minutes