Friday, December 01, 2006

Metabolism Myths


For the longest time I believed that if you dieted to strictly your metabolism would slow to a crawl. This was Bodybuilding dieting gospel.

Skip breakfast? Now you've slowed your metabolism down for the entire day. No way you’re burning any fat now!

Turns out, your metabolism is not that complicated. The idea that you have to keep your metabolic furnace stoked with food is a complete myth. Just another example of "experts" trying to make nutrition more complicated then it needs to be.

The portion of your metabolism that is affected by what you eat is very small. The largest part of your metabolic rate is set by your body weight. If you weigh more your metabolism is higher (especially if it's muscle), if you lose weight, your metabolism will go down.

The foods you eat effect your metabolism by something called "the thermic effect of food", which is the energy it takes your body to process the food you eat for storage or use, but again this is very small compared to the amount of energy it takes just to "run" your body.

It makes no difference metabolically whether you eat many small meals or one large meal. What does make a difference is the make up of these meals. Protein, carbs, fats and different ratios of each all have very small effects on the "thermic effect of food" which then has a very small effect on your metabolism.

Bottom line- It's still very important to eat "lean and green" and there are definite benefits to eating smaller meals throughout the day. But if you are looking to your diet as a way to control your metabolism, you're missing the boat.

The best way to increase your metabolism is with exercise. Other than drastic changes in bodyweight, this is the one way you can control your metabolism. Effective weight loss programs like Craig Ballantyne's Turbulence Training program or the ShapeShift program over at grrlAthlete.com are examples of good workout programs that can increase your metabolism.

Remember, if you miss a meal or cut your calories a little too low it doesn't mean you've shut down your metabolism. Your diet is still incredibly important in the fat loss process - (In my opinion it's even more important than your workouts), It’s just not the main regulator of your metabolic rate.

BP

Fasting for Weight Loss , Circuit Training for Women

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1 comment:

Brad Pilon said...

Hi Robert,

It is a very radical change from the current trend, but not a large change from what we know about metabolism.

We know that our bodyweight is the best predictor of our energy expenditure. It makes sense that it would take more energy to move around a larger mass.

Since most literature puts our basal metabolic rate at anywhere from 70 to 80 percent of our total daily energy expenditure, this leaves a very small amount to be affected by our food and exercise.

And since exercise involves moving large masses, again it makes sense that this would take more energy then digesting and utilizing stored energy in the form of food.

That leaves us with a very small percentage of our daily metabolism that can be affected by the foods we eat.

In terms of studies examining the effects of meal frequency and caloric content on metabolism…my three favorites are:

Br J Nutr. 1993; 70(1):103-15. Effect of the pattern of food intake on human energy metabolism. Verboeket-van de Venne WP, Westerkerp, KR, Kester AD.

Eur J Clin Nutr. 1991; 45(3):161-9. Influence of the feeding frequency on nutrient utilization in man: consequences for energy metabolism. Verboeket-van de Venne WP and Weseterterp KR.

J Am Coll Nutr; 1999; 18(2): 115-121. Effects of resistance vs aerobic training combined with an 800 Kcal liquid diet on lean body mass and resting metabolic rate.

Hope these help,

BP