Dec. 14, 2012 -- Adding essential amino acids and whey protein to a weight loss plan appears to increase fat loss, according to new research.
The study was done in older, obese adults, but the strategy may also work for younger adults, says researcher Robert Coker, PhD. He is an associate professor of geriatrics at the University of Arkansas for Medical Sciences, Little Rock.
In his new study, he compared two kinds of meal replacements. One was a protein replacement without essential amino acids. The other was a meal replacement with essential amino acids and whey protein.
The replacement with whey won.
"Essential amino acids, included as part of a meal replacement, along with whey protein, improved the synthesis of muscle and led to a greater loss of fat," he says.
Both groups lost about 7% of their total body weight. But the amino acids and whey group lost a greater percentage of fat to lean tissue.
Increasing fat loss during a weight loss program translates to a better and healthier body composition, experts say.
Coker studied 12 obese men and women, all 65 to 80 years old.
They were assigned to the meal replacement group or the meal replacement with amino acids and whey group. All were allotted 1,200 calories a day.
Coker evaluated the 11 who completed the eight-week program to see the effect of each plan on fat and muscle.
The meal replacement with whey and amino acids did not preserve lean muscle tissue much better than the other meal replacement.
It did boost fat loss. At the start of the study, the meal-replacement-alone group was about 39% fat; at the study end, they averaged 37.5% fat. The group getting meal replacement with amino acids and whey had 41.8% body fat at the start but 36.3% at the end.
Body weight losses were similar -- both groups started at about 200 pounds and finished at an average of 185.
The whey and amino acid supplement ''increased muscle metabolism, and this may have triggered a greater reduction in body fat," Coker says.
Could the same strategy help younger adults? "I think the answer potentially is yes," Coker says. His study looked only at those 65-plus, and they were obese. But other research has indicated the approach could help younger people, he says.
Losing excess body fat is an important goal, Coker says. Among other effects, it promotes inflammation and insulin resistance, making the body less apt to use insulin effectively.
The product studied by Coker is not available to the public.
The study was supported by an NIH Small Business Innovation Research grant and other grants. The small business grant was administered through HealthSpan, which makes a whey protein product. Coker and other co-authors were compensated by HealthSpan as consultants for the grant.