A calorie is a unit of energy used to measure the energy a food or beverage provides from the carbohydrate, fat, protein, and alcohol it contains.
You need energy to work, play, and even survive to breathe, move, pump blood, rest, sleep- and you acquire this energy from food. The number of calories in a food is a measure of how much potential energy that food possesses. In other words, calories are the fuel you need to function. Note that when choosing what to eat and drink, it’s important to get the right mix – enough nutrients, but not too many calories.
Recommended daily calorie intake varies from person to person, but there are guidelines for calorie requirements you can use as a starting point.
UK Department of Health Estimated Average Requirements are a daily calorie intake of 1940 calories per day for women and 2550 for men.