If one gram of fat contains 9 calories, and there are about 454 grams in a pound, how come 1 pound of fat is commonly equated to be about 3,500 calories instead of about 4,000 calories?

Question

If one gram of fat contains 9 calories, and there are about 454 grams in a pound, how come 1 pound of fat is commonly equated to be about 3,500 calories instead of about 4,000 calories?

In: 10

Answer 1

In fact that 9 cal / g is a big rounding, if you google 100g, you get 841 cal, which is 8,41 cal/g. With that number you get 3800 cal/pound (much closer to 3500).

It is known that these numbers are often rounded to an approximation for easier to remember or because anyways there can be some variance between fat and fat.