Monday, September 9, 2013

Extra Protein May Minimize Muscle Loss During Dieting

The Study  One of the big challenges of losing weight is preventing muscle loss. When you lose weight by cutting calories, you always lose some of that as fat and some of that as muscle. But you want to minimize that muscle loss because muscle burns more calories than fat and also helps to keep you strong.
In a recently published study, researchers showed that when study participants on a weight loss diet were put on twice the recommended level of protein, they lost more fat and less muscle than the participants at the recommended level of protein intake. Participants who ate three times the amount of recommended protein did not get any extra benefit.
Everyone lost weight in the study – about 7 pounds for the people on the lower protein diet and just under 6 pounds for the people on the double protein diet over 21 days. But the people on the lower amount of protein (the recommended level) lost 58% of their weight as muscle while the people in the 2x protein group only lost 30% of their weight as muscle. The other 70% of weight lost was as fat.

Some cautions on this research:
  • Small Study.  There were 12 to 14 people in each of the study groups – that’s small and those 12 to 14 people may not be like the rest of us! 
  • Short Study. The weight loss portion of the study only lasted 21 days – so we can’t say what would happen long term.  
  • Was it the protein? It is possible that because the people in the double protein group lost a little less weight, that the lower weight loss itself could have accounted for losing less weight as muscle.
So this finding is not conclusive by any means but it does raise this idea that we may be able to minimize muscle loss on a low calorie diet by boosting protein.

Protein Recommendations
  So what is the recommended level of protein now? It is 0.8 grams of protein per kilogram of body weight. To change your body weight from pounds to kilograms, you divide by 2.2. So the protein needs for someone who weighs 220 pounds looks like this:

220/2.2 = 100 kilograms body weight    
100 kilograms x 0.8 grams/kilogram of protein = 80 grams of protein

So, if this person wanted to lose weight, you would double that to 160 grams of protein a day. Now things get a little complicated at this point because the rest of the diet also has to be adjusted to accommodate this increase in protein. Just increasing your protein intake won’t help you lose weight. In fact, you would probably gain weight from the extra calories!

So, you have to lower your overall calorie intake to a reasonable level that will help you lose weight. Then, you have to calculate how much fat and carbohydrates fit into your diet. In this study, the researchers had the participants eat less than 30% of their calories as fat and then added the rest of the calories in as carbohydrate. The bottom line is that you may want to consult with a registered dietitian to help you devise a plan that is accurate and works for you! Getting all that extra protein may not be as easy as you think. Here’s a list of the top dietary sources:

Best Protein Sources:
4 ounces of lean meat: 28 grams
1 cup skim milk: 8 grams
1 egg: 6 grams
4 ounces Greek yogurt: 12-14 grams
1 ounce of cheese: 7 grams
½ cup tofu: 10 grams
1 cup soy milk: 6 grams
½ cup pinto beans: 7 grams

Beth Kitchin PhD, RD
Assistant Professor Nutrition Sciences
University of Alabama at Birmingham

Source: Pasiakos, S. M., Cao, J. J.,Margolis, L. M., Sauter, E. R., Whigham, L. D., Mc-
Clung, J. P., Rood, J. C., Carbone, J. W., Combs, G. F.,Jr., Young, A. J.
Effects of high-protein diets on fat-free mass and muscle protein synthesis following weight loss: a randomized controlled trial. FASEB J. 27,
3837–3847 (2013).

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