If there is any motto for the aspiring physical fitness fan, it should be "Burn The Fat Feed The Muscle". The key is always to get diet right. You simply have to eat enough calories to maintain and grow your muscle mass. You also have to be sure not to consume so many calories that you increase your fat mass.

Most people fail the burn fat, build muscle test. The average exerciser who works out an hour a day for four months, one American study found, gains one pound. The average person who stays on Weight Watchers for a year also gains one pound. Hundreds of hours in the gyms or hundreds of skimpy meals won't do the trick unless you know the basic equation that enables you to burn fat build muscle. And here it is in two straight-forward, although not necessarily easy, steps:

1. Calculate your calories.

To do this you need to know your target weight and how many hours your exercise each week. If you don't exercise at all, multiply your target weight by 10, and that's the number of calories you should consume each day. If you exercise, then add 1 to the multiplier for each hour your work out each week.

For instance, if you work one hour a week, and you want to weigh 175 pounds, multiply 175 by 11 and you get 1,925 calories a day to reach your goal weight. If you work out two hours a week and you want to weigh 175 pounds, multiply 175 by 12 and get 2,100 calories a day to reach your goal weight.

2. Distribute your calories.

Now you'll figure out the right ratio of protein, fat, and carbohydrate in your diet. You need protein to maintain and build muscle. You need healthy fat to make hormones, including the hormones that your fat cells send to your brain to tell it that you don't need to eat more. And you need carbohydrates for energy, both resting energy (breathing, digesting food, and so on) and the energy you use in exercise.

You need 1 gram of protein for every pound of ideal body weight. In the example above, that is 175 grams of protein a day.

You need 1/2 gram of fat for every pound of ideal body weight. In the example above, that is 87.5 grams of fat a day.