Lean body mass tends to have an underappreciated role in health and disease. The human body's muscle mass plays a key role in metabolism.
It's a reservoir for amino acids used to synthesize proteins in vital tissues and organs, such as the brain, heart, liver, and skin.
It's also a reservoir for amino acids used in a process that occurs in the liver known as gluconeogenesis. That is a fancy name for the conversion of amino acids to glucose. This helps maintain normal blood glucose levels.
Muscle mass also plays a central role in various conditions, such as in obesity, diabetes and insulin resistance, and osteoporosis. Yes, as lean mass is lost, there is a greater risk of losing insulin sensitivity and of experiencing metabolic disturbances.
What would be easier to do - restore lost muscle mass or prevent it in the first place? Ideally, we would want to focus our efforts on preventing muscle loss in the first place. Restoring muscle mass becomes harder as we age, especially for elderly individuals.
PRESERVE LEAN BODY MASS
What are the best things you can do to preserve lean body mass?
For one thing, studies suggest that protein intake is important for maintaining lean mass. In fact, protein intake was so important to preventing loss of lean mass that expert recommendations of protein intake for older adults at only 0.8 grams/kg of body weight were ultimately considered to be insufficient. The recommendation has increased to at least 1.0-1.2 g protein/kg body weight.
Exercise is another well-established method to increase muscle mass. Not only does exercise help build muscle mass but it is significantly effective at preventing loss of muscle mass.
A study published in the February 2017 issue of the Journal of the Academy of Nutrition and Dietetics found a strong relationship between protein intake and lean mass percentages. The study also found that exercise can amplify this relationship. This study was done on postmenopausal women.
- Women with the highest intakes of protein had the highest lean mass percentages.
- Women with the highest intakes of protein and who reported the highest levels of physical activity had higher lean mass percentages and lower fat mass percentages.
The studies suggests a combined benefit of high dietary protein intake and physical activity for women across all BMI groups, even overweight or obese BMIs.
Fad diets. Strict, calorie-counting diets. Impractical diets. People have tried everything to lose weight and gain lean muscle mass.
These results may be particularly encouraging for those who have trouble simply cutting calories. This study suggests that your protein intake can directly affect your muscle mass. Also, the best way to maximize the benefits of the protein in your diet is to combine it with physical activity.
It is not surprising, then, that many studies in the past have shown how efficient high protein diets are for enhancing weight loss and weight maintenance. 4,5 A 2012 study published in the journal Physiology and Behavior found that weight loss depended on a high-protein diet, not necessarily on a low-carb diet. 4 A similiar study found that high-protein diets not only help with weight loss but they help prevent weight regain after losing weight.
While current recommendations suggest the average healthy adult needs about 0.8 g protein/kg of body weight, this study found that protein intake of up to 2.02 g/kg body weight was positively associated with lean mass. It's studies like these that may move experts to revisit recommendations for optimal protein intake.
In the meantime, it is important to choose healthy sources of high quality protein. High quality protein sources include whey protein, eggs, milk, yogurt, cheese, fish and seafood, lean poultry, grass fed beef, beans and pulses, nuts, soy and tofu.
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2. J Acad Nutr Diet. 2016 Nov 30
3. Med Sci Sports Exerc 2004; 2073–81.
4. Physiol Behav. 2012 Oct 10;107(3):374-80.
5. Int J Obes Relat Metab Disord. 2004 Oct;28(10):1283-90.
6. Int J Obes Relat Metab Disord. 2004 Jan;28(1):57-64.