What is a calorie?

Some labels show energy in kilojoules (kJ) instead, so check which unit is used.

Why calories matter

Your body uses energy all day, to breathe, think, digest food and move.

NHS explains that when the calories you eat match the calories you use, your weight stays roughly the same.

• Eat more than you use and the extra is stored as fat.
• Eat less and your body draws on its fat stores.

As a rough guide, NHS says an average woman needs about 2,000 kcal a day and an average man about 2,500.

Your own needs depend on your age, size and how active you are.

Why calories aren't the whole story

Calories aren't the whole story: a samosa and a bowl of sprouts with the same calories affect your hunger and health very differently.

Still, it helps to know where they hide. These add up quickly:

• ghee and oil
• sweets and namkeen
• sugary chai and juices

Read labels and serving sizes, and fill up on vegetables, dal and whole grains, which give you more food and nutrients for fewer calories.