Diets are everywhere, but could eating “negative calorie” foods, such as celery and grapefruit, help to boost weight loss?
A calorie is a unit of energy, usually expressed as kilocalories (kcal) for the energy content in food. The theory behind negative calorie foods is that some foods have lower calorie (energy) content than the amount of energy it takes to digest and absorb the food into the body. This sounds plausible, in theory. But in reality, even the lowest calorie foods, such as celery, contain more calories than it takes to break down and absorb them in the body.
Our energy needs are made up of three components:
• The energy needed to maintain a body at rest, which is the energy needed for our body to carry out its basic processes so we can live.
• The thermic effect of eating, which is the increase in metabolic rate after eating, while food is digested and absorbed.
• Additional energy needed for activity and exercise.