Christian Finn writes

Not concerned about muscle?
Think again!

I take seriously a recent article by Christian Finn, "Are you losing muscle as well as fat?"

It's no secret that dieting on its own will cause not only fat loss but muscle and bone loss. So how much muscle and bone are you willing to lose?

Muscle loss with age (sarcopenia) is a serious health threat. What's more, you can expect that bone loss will match muscle loss. I want to lose fat and gain back some of the muscle and bone I have already lost due to aging. So the title of Christian's article caught my eye.

I consider carefully whatever Christian Finn writes because his articles are based on sound scientific research. This article is based on research carried out by a team at the University of Illinois led by Donald Layman.

For four months, the researchers studied the effect of nutrition and exercise on 48 women with BMI = 33 and average age about 42. Two groups of women walked about 100 minutes extra per week, 15 minutes per day. Another two groups walked 20 minute per day and did resistance training for 30 minutes twice per week. Women in all groups lost about 18 pounds on average. [About 10% of body weight.]

Now here come the key bits:

• Women who only walked lost 5 pounds of muscle, 28% of total weight lost. Women who also did weight training lost about 1.5 pounds of muscle, only 8% of weight lost.
  
  
• Each group of women was sub-divided into two sub-groups. The high-protein sub-group ate twice as much protein as the low-protein sub-group. The women who ate more protein lost more weight than the women who ate less protein, 20.5 pounds compared with 16 pounds. However, the women who ate less protein lost twice as much muscle, 25% compared with 12%.
  
  
• Women who ate more protein and who worked out with weights lost 21 pounds of fat and one pound of muscle, while women who ate less protein and only walked lost 11 pounds of fat and 6 pounds of muscle.
  
  Think about it: The object is to lose fat, not bone and muscle. By eating more protein and working out with weights, the women lost more weight and only 5% of the loss was muscle. By eating less protein and only walking, the women lost less weight and 35% was muscle! [The researchers did not measure the amount of bone loss. The estimate for muscle loss probably includes bone loss.]
  
  
• For this study, the high-protein diet included 1.6 grams per kg of body weight of protein per day, 0.7 grams per pound of body weight. For a person weighing 150 pounds (68 kg), this would be 110 g of protein per day. The amount of protein in foods varies depending on the type of food and water content. For example, sirloin steak (23%), canned salmon (16%). Beans and grains complement each other to provide a complete protein, averaging around 10%. The Harvard School of Public Health is a useful resource for facts about protein. Harvard sounds a note of caution about high protein consumption over many years, but also suggests that the real culprit may be lack of calcium needed to neutralize the protein.