And 3,500 calories of fruit, whole grains, and vegetables is no easy task. I come close to that on some days, as I bicycle 3+ hours at a time multiple times per week, and eat extremely lean (95%+ whole plants), and getting that many calories with that much fiber can make me feel extremely uncomfortable, like my stomach is going to explode. Even on a rest day when I'm eating < 2,000 calories with no processed foods or animal products, I feel full all day long.  But let's not kid ourselves. This fat is eating garbage, and probably eats so little fiber she shits once a week at most.