Bodybuilders have long known that if you eat too little for too long, you can actually decrease your resting metabolic rate (the number of calories you burn at rest).

Now, scientists are catching up to our muscle-building friends. Researchers from the Pennington Biomedical Research Center in Louisiana studied long-term dieting in 48 normal-weight subjects.

For six months, one group of subjects reduced their calories by 25 percent. A second group reduced their calories by 12.5 percent and exercised to burn another 12.5 percent of their calorie intake each day. A third group consumed only 890 calories per day until they lost 15 percent of their body weight, and then went on a weight-maintenance diet.

The researchers found that resting metabolic rate decreased after only three months in the subjects who’d reduced their calories by 25 percent. The 890-calorie-per-day group and the diet + exercise group also had a decreased resting metabolic rate, but it took six months for them.

The conclusion: When you diet too hard and too long, your body starts to conserve energy by reducing your metabolism and by decreasing the number of calories burned in any exercise you do.

To keep your resting metabolism high, follow these three guidelines when trying to lose weight:

1. Don’t cut your calories too much. A 10 percent reduction – combined with regular exercise – is plenty.

2. Permit yourself a “reward meal” once a week. Eat your favorite foods, but don’t go over the number of calories you had been eating each day before you started the diet.

3. Every eight to 10 weeks, take a few days off of dieting, and go back to your pre-diet caloric intake.

[Ed. Note: Supplement Craig Ballantyne’s diet rules with a fat-burning exercise routine. Learn how to build muscle and blast fat with his Turbulence Training program.]

Craig Ballantyne

Craig Ballantyne is the author of The Perfect Day Formula: How to Own the Day and Control Your Life. Craig has been a contributor to Men's Health magazine for over 17 years. Today he teaches his gift to high-performing entrepreneurs how to squeeze more out of their days, increase their income, and make more quality time for their families in his Perfect Life Workshop and Work-Life Mastery programs. Craig used his own advice to overcome crippling anxiety attacks in 2006, and he'll teach you his 5 Pillars of Success so you can increase your income, decrease your work time, and live the life of your dreams. Learn more about Craig at

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