To lose one pound of fat, you must burn approximately 3500 calories over and above what you already burn doing daily activities. That sounds like a lot of calories and you certainly wouldn't want to try to burn 3500 calories in one day. However, by taking it step-by-step, you can determine just what you need to do each day to burn or cut out those extra calories. Below is a step by step process for getting started.
1. Calculate your BMR (basal metabolic rate). Your BMR is what your body needs to maintain normal functions like breathing and digestion. This is the minimum number of calories you need to eat each day. Keep in mind that no calculator will be 100% accurate, so you may need to adjust these numbers as you go along.
2. Calculate your activity level. Use a calorie calculator to figure out how many calories you burn while sitting, standing, exercising, lifting weights, etc. throughout the day. It helps to keep a daily activity journal or you could even wear a heart rate monitor that calculates calories burned.
3. Keep track of how many calories you eat. You can use a site like Calorie Count or use a food journal to write down what you eat and drink each day. Be as accurate as possible, measuring when you need to or looking up nutritional information for restaurants, if you eat out.
4. Add it up. Take your BMR number, add your activity calories and then subtract your food calories from that total. If you're eating more than you're burning, (your BMR + activity is 2000 and you're eating 2400 calories) you'll gain weight. If you're burning more than you eat, you'll lose weight.