Because your body is accustomed to a certain lifestyle and diet, it will return to craving those things, slowing its metabolism, and building up yeast as soon as your program is finished. Even while you do your best to exercise, eat right, and cut out sugar, your body will continue to crave the heavily processed foods you must avoid. This means you may always want that late-night dessert, morning donut, and lunchtime order of french fries. When you slip, your body will hold on to those carbs and sugars, building up visceral fat, and preventing your metabolism from functioning at full force.