If you are trying to lose weight, all the exercise you can fit into your day is not going to help if you aren't also watching what you eat. Your food intake works with your metabolism and activity level to help you lose weight. Think of your metabolism as a low-burning fire that you have to constantly stoke and feed. If you add too much fuel you risk smothering it, and if you don't add enough, it might just die out. Your food is your fuel, and eating several small meals and snacks throughout the day helps with weight loss and fires up your metabolism. The food you eat goes to short-term storage in your muscles as glycogen, which provides the energy you need for daily activities. There's only so much glycogen that your muscles can store at one time, and excess calories end up in long-term storage, which contributes to weight gain. If you eat just enough calories, your body is able to consume it throughout the day, without storing any extra. Healthy snacking throughout the day also helps to keep blood sugar levels steady, without the sudden spikes and dips that lead to cyclical fatigue, cravings, and hunger pangs. Depending on your weight loss goals, try to eat 100 to 200 calorie snacks three times a day, and keep your meal portions to between 300 to 500 calories. A deficit of 3500 calories should equal a pound lost, but sometimes eating too few calories can stall out weight loss. The general guideline is to never dip below 1200 calories, but you should also adjust your calorie intake upward based on your weight and how much you work out.