In general, a woman who is trying to lose weight will take in 1,200 calories per day, while a man can take in up to 1,800 calories a day. So try to split your meals and snack in such a way as not to go over these values – three meals of 300 calories and snacks amounting to 300 calories, if you are a woman, and three 450-calorie meals and snacks amounting to the same value, if you are a man. Weight yourself periodically, because, as you lose weight, you need fewer calories, and this will subsequently lead to eating less.