A pound of body fat contains roughly between 3,436 and 3,752 calories, with the commonly cited figure being about 3,500 calories. This estimate originates from research in the 1950s by Max Wishnofsky, who calculated that since body fat tissue is approximately 87% fat and pure fat contains about 9 calories per gram, one pound (454 grams) of body fat equates to about 3,500 calories
. However, it is important to note that body fat is not pure fat; it also contains water and protein, which lowers the actual calorie content compared to pure fat, which has about 4,100 calories per pound. Different types of fat and individual variations can cause some fluctuation in this value
. While the 3,500-calorie rule is a useful general guideline for weight loss, it oversimplifies the process. It does not account for metabolic adaptations and changes in energy expenditure that occur with weight loss, which can affect how many calories must be burned to lose a pound of fat
. In summary:
- One pound of body fat ≈ 3,500 calories (range: 3,436–3,752 calories)
- Body fat is about 87% fat; the rest is water and protein
- Pure fat contains about 9 calories per gram (~4,100 calories per pound)
- The 3,500-calorie rule is a simplified estimate and may not precisely predict weight loss due to metabolic changes
This makes the 3,500 calorie figure a practical but approximate benchmark rather than an exact number.
