Technically speaking, one calorie is the measure of heat needed to warm one kilogram of water by one degree Centigrade. Less technically, for us common folk, a calorie is a unit of heat energy.
When foods are broken down in the body, they give off different amounts of energy as heat. This energy is quantified as calories. Carbohydrates and proteins provide four calories per gram, fat has nine calories per gram, and alcohol serves up seven calories per gram.
You probably have heard that in order to lose weight you’ll need to create a calorie deficit. A 𝐜𝐚𝐥𝐨𝐫𝐢𝐞 𝐝𝐞𝐟𝐢𝐜𝐢𝐭 is achieved by burning more calories than you consume. It’s commonly understood that to burn one pound, you’ll need to create a deficit of 3,500 calories.