HUMAN NUTRITION

Detailed explanation-1: -One calorie is defined as the amount of energy needed to raise the temperature of one gram of water by one degree Celsius at a pressure of one atmosphere.

Detailed explanation-2: -The calorie was originally defined as the amount of heat required at a pressure of 1 standard atmosphere to raise the temperature of 1 gram of water 1° Celsius. Since 1925 this calorie has been defined in terms of the joule, the definition since 1948 being that one calorie is equal to approximately 4.2 joules.

Detailed explanation-3: -A calorie is the amount of heat it takes to raise the temperature of 1 gram (0.001 liters) of pure water 1 degree C at sea level. It takes 100 calories to heat 1 g.

Detailed explanation-4: -Answer and Explanation: A calorie is the amount of energy required to raise the temperature of 1 gram of water by 1 degree Celsius.