Calories

Definition of "calorie": Calorie is a unit of energy, usually used to measure the energy contained in food or the energy consumed by the human body during activities. 1 calorie is equal to the energy required to raise the temperature of 1 gram of water by 1 degree Celsius.
Calories are very important in nutrition because they help us understand the energy value of food and our energy needs. When we consume more calories than our body needs, the excess energy is stored as fat, which may lead to weight gain; conversely, if we consume insufficient calories, it may result in weight loss or energy deficiency.
For example:

A slice of pizza contains approximately 285 calories.
A glass of water contains almost zero calories, but if sugar or other ingredients are added, the calorie count increases.

The origin of calories can be traced back to the 19th century, first proposed by French chemist Nicolas Clément, and gradually became widely accepted and used in subsequent scientific research.

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