We need calories or (1)…………………..to do the things every day. For example, when we walk to school or (2) ………………..a bike to school we spend a certain amount of (3)………….and even when we sleep, we also use them. But how many calorie should we (4) ………………a day to stay in shape? It’s difficult (5)…………………..us to calculate. If people want to keep (6) …………….., they should remember that everyone should have between 1600 and 2500 calories a day.