Is eating 500 calories a day without exercising bad?

Move. Exercise.: Eating 500 calories a day is too little. That's just one big slice of pizza a day. A 4-month old baby eats 500 calories a day. Anybody on 500 calories a day is on a starvation diet and will lose weight. It doesn't sound safe. Extremely low calorie diets don't work because the weight comes back when one starts eating again. Long-term lifestyle changes are needed.