Somehow it's just not fair

One pound equals 3500 calories.

To lose a pound a week, eat 500 calories fewer a day.

Since the average person needs around 2000 calories a day, it is impossible to eat 3500 calories fewer a day (or to exercise 3500 calories extra in a day).

It is, however, possible to eat 3500 calories extra in a given day.

=/ Kk.