Uncategorized

April 13, 2010

Protein Intake When Dieting

There remains great debate as to whether a high carb/low fat or low carb/high fat diet is best for weight loss. The majority of research seems to suggest that there is no definitive answer on the topic; results ultimately depend on individual genetics. Studies show that people respond differently to different dietary protocols; some do better with higher carbs, some with lower carbs. I’ve addressed this issue in a previous post on Diets for Your Genotype.

One thing that is not in doubt, however, is that a higher protein intake is universally essential when restricting calories–much more important than the percentage of carbs versus fat. A large body of evidence shows that when dieters consume a low protein intake, the body cannibalizes muscle tissue for fuel. As much as 1/3 of the body’s muscle is lost on a calorie-restricted diet when protein is kept at the RDA (approximately 0.8 grams per kilogram of body weight). Given that muscle plays a role in helping to maintain metabolism, its loss is a primary factor in weight loss plateau and subsequent weight regain.

Fortunately, muscle loss is significantly attenuated when greater levels of protein are consumed. A recent study by Gordon and colleagues showed that increasing protein from 15% of total calories to 30% of total calories reduced the amount of muscle loss by more than half in subjects consuming a low-calorie diet! These findings are supported by multiple other studies on the subject.

So how much protein should you consume when dieting? Studies suggest that about one gram of protein per pound of ideal bodyweight is needed to confer optimal benefits. Thus, if your target weight is 130 pounds, then you should consume about 130 grams of protein a day. Of course, adding resistance training to the mix can not only completely reverse muscle loss, but actually promote muscle development while losing body fat. So if you’re looking to get lean and defined, cut calories while maintaining a higher protein consumption and remember to lift those weights!

A word of caution: If you have existing kidney disease, higher protein intakes are generally contraindicated as they can overstress damaged kidneys. Make sure you coordinate any dietary changes with your physician.

Stay Fit!

Brad

Gordon MM, Bopp MJ, Easter L, Miller GD, Lyles MF, Houston DK, Nicklas BJ, Kritchevsky SB. (2008). Effects of dietary protein on the composition of weight loss in post-menopausal women. J Nutr Health Aging, 12(8):505-9.