" ~~Elizabeth Somer, M.A., R.D. REACHING YOUR FAT-LOSS GOALS may be easier than you think. To lose a pound of fat a month, all you need to do is cut 100 calories a day from your diet, assuming the intake and expenditure of all other calories remains the same. That's because a pound of body fat is equivalent to about 3,500 calories. The FATFREE Recipe Collection.