That is definitely not the case for me as I had my gallbladder removed as it was thought a likely possibility for causing pancreatitis which I had had twice (but now, it is thought it was actually my birth control pills causing the pancreatitis, not the gallbladder which looked perfect once they removed it). I have always eaten healthy and exercised heavily as a ballet dancer my whole life and after the surgery I have gained 20 lbs in a few months with the exact same diet and exercise. Before gallbladder surgery I COULD eat because I did not have mine removed for gallbladder disease, but as a possible cause for the severe pancreatitis, so the weight gain is NOT attributable to not being able to eat, but rather to now not having a gallbladder which is apparently a lot more essential to weight that the doctors told me.