Why do I feel faint and dizzy on a diet if i dont eat between meals? Ive been on a diet for a few weeks, Ive been trying to eat low cal, nutrition dense foods while cutting out suger and things like white bread and pasta. Ive also cut out all snacks between meals. I was ok for about 2 days, but now ive noticed that i get really dizzy and shakey and disoriented between meals. My heart jumps all over the place and a few times ive nearly passed out. I also feel really dizzy if i sit down for too long. The only thing that seems to fix it is something sugery like a full fat yogurt or coke or sports drink which I try not to have because suger is so fattening. Ive tried healthier snacks but i still end up feeling weak. Im over weight for my height ( 164 and 55kg) and im trying to loose around 8kg but the things ive been experiencing are stopping my diet. What is wrong with me ?