Statistically speaking, if you keep a detailed journal of nutrition and antrenament,constantly watching your weight and monitor other factors, you can reach conclusions about "average". Find out how much you eat, how much you burn, how much weight loss or gain. However, medium and long term weight loss balance is finer than that(talking about the equivalent of tens or hundreds of calories a day), errors and deviations from the estimates for most because of failure when trying to keep a strict and weigh food "per gram". If you want to see how many calories you need to burn use our calorie calculator.
