How do we know how many calories are burnt?

Question

For example one burns about 200 calories while taking a walk.
Who figured that out and how?

In: 8

Answer 1

We measure the heat evolved. A calorie is the energy needed to raise the temp of a kg of water by one degree. It is a misnomer, when applied to nutrition. Your body does indeed produce heat as a bi-product, but it does not correlate to the food you have eaten, or the fat you have stored. The true answer is that thinking of nutrition and metabolism in these terms is inconclusive at best, fraudulent at worst. The entire concept of calorie counting or calculation as it pertains to nutrition is deeply flawed for several reasons. It’s scam science.