Energy demand

It is important to know what you should eat. Yet, far more important is to know how much you can eat. Permanently high level of calories (no matter whereof) will sooner or later result into weight gain and undesired love handles. The number of your daily calories, your energy demand, is based on the correlation between your basic metabolic rate (BMR) and physical activity level. Both depend on different factors such as age, physical activity and lifestyle.
Your energy demand can be calculated in the following way:

Energy demand: BMR x physical activity level
BMR women: 7 x weight in kg + 700 kcal
BMR men: 7 x weight in kg + 900 kcal
Physical activity level: 1 x sport per week = 1.4
2 x to 3 x sport per week = 1.7
at least 4 x sport per week = 2.0

daily energy demand of a woman, 60 kg, 3 x trainings per week:
BMR: 7 x 60 kg + 700 kcal = 1120 kcal x 1.7 = 1904 kcal

But don’t worry. This doesn’t mean that you should strictly count every consumed calorie. More important is that you have the right weekly balance.
Try to reduce your daily calorie intake during the diet no more than by 300 - 400 kcal; otherwise the result will be exactly the opposite. Your metabolism decreases and this inevitably leads to the yo-yo effect.

Expert tip:
Write down what you have eaten for an entire week and calculate the calories. This will help you to understand whether your food consumption corresponds to the energy demand!