How much muscle did you lose while on that last diet? Too much, probably, according to research showing that dropping pounds could mean losing valuable lean muscle. Dietary protein requirements are usually expressed as 15 to 20 percent of total calorie intake. When someone reduces calories, the amount of protein they eat may drop as a result of decreased overall intake. A few scientists have even suggested regular dieting could be harmful since muscle is a crucial tissue for so many facets of long-term health.
Dietary protein has long been thought to be the key to protect against dieting-induced muscle loss. Now, a new long-term study from various universities, headed by researchers at the University of Georgia, is confirming that eating higher amounts of quality protein while reducing calories can help maintain muscle mass at the same time as losing weight.
The Persuasive Results
In a 12-month randomized clinical trial, published in Nutrition and Metabolism, 130 middle-aged subjects went through a four-month period of weight loss followed by eight months of weight maintenance. Some were placed on a calorie-reduced diet that were either high-protein (30 percent of intake from protein) or low-protein (15 percent of intake from protein). The two diets were formulated to be equal in total calories, total fat, as well as fiber content. Physical activity was accounted for and found to be similar between the groups.
While both groups lost weight, researchers found that more fat relative to lean body mass was lost in the high-protein group compared to the low-protein group. In the low-protein group there was about a 40 percent loss in lean tissue, while only 21 percent and 25 percent was lost in the high-protein group for men and women, respectively.
This study’s results add to evidence that a diet higher in quality protein during calorie restriction helps to retain muscle mass. Because proteins are metabolized in muscle, they have anabolic effects. This means more muscle tissue will be grown and muscles will be repaired faster. The protein content of a meal, especially one high in branched-chain amino acids (BCAA), boosts this reaction. BCAA is the name given to three of the eight essential amino acids needed to make protein: leucine, isoleucine and valine. The combination of these three essential amino acids makes up approximately one-third of skeletal muscle in the human body.
Where Can I find BCAA’s in food sources?
Typical protein contains 15-20% BCAA and whey protein can have up to 25% BCAA. Out of all of the protein choices, Whey protein has the best BCAA content. Other good sources of BCAA:
- Leucine – fish; chicken; eggs; lentils; chickpeas; seeds; almonds and cashews
- Isoleucine – ike beans, brown rice and milk
- Valine – fish; grains; mushrooms; peanuts; vegetables and cottage cheese.
And yet Protein does even more!
Besides building cells and repairing tissue, they form antibodies, they are part of the enzyme and hormonal system; they build RNA and DNA and they carry oxygen throughout the body. In a study, a group of healthy people received a single intravenous infusion of these amino acids, the amount of tissue breakdown that normally occurs overnight decreased by 50 percent. In another study, the muscles of a group of marathoners and cross-country runners were spared completely with a daily dose of them.
Today’s lesson was brought to you by the letter P. Protein packs a powerful punch of health! For a lifetime of muscular strength and overall wellbeing, seek a protein rich diet with BCAA’s.