Calories

See also: Basal Metabolic Rate and Total Daily Energy Expenditure

A calorie is a unit of measurement that measures energy. Calories are used to measure the energy content of foods and beverages. The calories in food and drinks refer to the amount of energy supplied from the carbohydrates, fat, protein, and alcohol in a serving.

A calorie is also known as a kilogram calorie (Cal). A calorie (kcal) is the amount of energy needed to raise the temperature of 1 kilogram of water 1 degree Celsius.

To lose weight, you need to eat fewer calories than your body burns each day. Conversely, to gain weight, you need to consume more calories than you expend.

The average adult woman expends roughly 1,600 to 2,400 calories per day, while the average adult man expends 2,000 to 3,000.

Some unhealthy high-calorie foods include:

Processed foods, such as bacon, salami, and other processed meats
Fast foods, such as burgers, fries, and pizza
Fried foods, such as onion and french fries
Packed foods, such as chips, biscuits, chocolates, cakes, soft drinks, or ice cream