1,A calorie is a unit of energy that helps US to do our daily activities

2,We can be fat

3,We need from 1600 to 2 500 calorie per day

4,,Sports activities like  riding a bike a running use a lot of calories

5,Because he is diet expert .

1. A calorie is energy, we need to do things every day 

2.If we eat too many  calories, we will become fatter

3.People should have between 1,600 and 2,500 calories per day

4.Activity uses a lot of calories is sports such as :riding a bike,running

5.Because he is a diet expert