Fat and lean mass make up the composition of your body. Lean mass is considered your bones, skin, water, connective tissue and muscles. Lean mass and fat mass are two separate forms inside your body. One cannot be turned into the other, so no foods can directly turn fat into muscle. The key to improving your body composition, i.e. the amount of fat vs. muscle you have, is to burn fat and build muscle. You can do this with dieting strategies and exercise.
Reducing Food Intake
By eating less food, you can reduce the amount of body fat you have. Eating fewer calories than your body uses in a day creates a caloric deficit. This forces your body to use the energy it has stored up, which is your fat. Creating a caloric deficit of just 500 calories a day can lead to a reduction of 1 lb. a week. There are 3500 calories in a pound of fat. A daily caloric deficit of 500 calories creates a deficit of 3500 calories in a week.
The amount of protein as well as the timing of your protein intake can work toward building muscle. Your protein needs depend on your physical activity level. Eating too much protein will not lead to guaranteed muscle. Like any other macronutrient, protein provides calories, and any extra calories beyond what you use will turn to fat. However, eating the right amount of protein as well as at the right time can help you work toward your muscle building efforts. Protein consumption after an intense exercise session is essential. After you work out, your body's muscle-specific building capabilities are elevated for up to 24 hours. To take advantage of this, you must consume protein for muscle building. Athletes should consume between 1.6 g and 1.8 g of protein per kg of body weight.
Your body will not build muscle without the right stimulus. Changing your diet to lose fat without exercise can result in a 25 percent loss of lean body mass for every pound you lose, according to the American Council on Exercise. Regular exercise works to burn calories, reduce fat and build muscle. Aerobic exercise is the calorie and fat burning activity that will best help you achieve your fat-loss goals. However, resistance exercise is the activity that will build muscle.
Safety and Guidelines
It is generally safe to lose about 1 percent of fat mass a month, according to the American Council on Exercise. This equates to a loss of about 1 to 2 lbs. a week. A woman looking for fitness goals should aim to reduce her body fat to between 21 percent and 24 percent. A woman athlete should be somewhere between 14 percent and 20 percent body fat. A man wishing to improve fitness and health should have a body fat percentage of 14 percent to 17 percent, while an athletic male should aim for a body fat percentage of 6 percent to 13 percent.
- Mayo Clinic: Counting Calories -- Weight Loss Basics
- "Optimum Sports Nutrition"; Dr. Michael Colgan; 1993
- ThinkMuscle; "Pre- and Post-Workout Nutrition To Maximize the Training Effect"; Bryan Haycock; 2010
- American Council on Exercise; "What Are the Guidelines for Percentage of Body Fat Loss?"; Natalie Digate Muth; December 2010