Ignore fad diets that promise you can lose fat from specific areas -- when you lose weight, you lose it equally from all over your body. Losing fat requires a combination of changes in your diet and exercise routine. You'll need a 3,500 calorie deficit to lose just one pound of body weight. The fastest way is to eat less -- so you're consuming fewer calories -- and to increase your activity level -- so you are burning more calories.
Push yourself physically with interval training. According to ABC News/Health, the fastest way to burn body fat is to vary the intensity of your workout between 65 percent and 85 to 95 percent of your total capacity. Interval training makes your body work both aerobically and anaerobically, leading to the most calories and highest amount of fat burned.
Cut down on your carbs to help your body burn fat for energy. Your body's primary energy source is glucose; going low-carb stops the easy supply of energy and forces your body to burn convert stored fat to fuel. This is the theory behind diets such as the Atkins, South Beach and Zone diets -- limiting over-all carbs and choosing carbs that have little impact on blood sugar levels, such as vegetables and whole grains. To lose the most amount of weight in one week, follow the induction phase of the Atkins or South Beach diet, which restricts carbs to about 25 g daily.
Add fiber to your diet. A high fiber diet can help you feel full longer and consume fewer calories. Fiber slows the digestion of food, helping you eat less at each meal and go longer between meals. You can try a fiber supplement right before your meals to cut calories. Be sure to increase your water intake -- too much fiber can cause constipation -- but staying hydrated will keep everything running smoothly.