TUESDAY, Jan. 3 (HealthDay News) -- It's too many calories, not
too much protein, that leads to unhealthy weight gain associated
with overeating, new research suggests.
In a "do-not-try-this-at-home" study, 25 healthy participants
followed diets containing different levels of protein -- plus
nearly 1,000 extra calories -- for eight weeks. The study took
place in an inpatient setting, where participants had just
completed weight-stabilizing diets for 13 to 25 days.
Those who ate low-protein diets gained less weight than the
other groups, but the quality of the weight gained was worse, as it
came from an increase in body fat. In contrast, the high-protein
diets led to changes in lean body mass and helped participants burn
"Most people are overeating and for those people who are, they need to pay attention to what they are putting into their mouths," said study co-author Leanne Redman, an assistant professor of endocrinology at Pennington Biomedical Research Center in Baton Rouge, La. "If you overeat a high-fat, low-protein diet, you may gain weight at a lower rate, but you are gaining more fat and losing more muscle."
The findings appear in the Jan. 4 issue of the
Journal of the American Medical Association.
The researchers looked at how the level of protein in the diets
affected body composition, weight gain and energy expenditure under
tightly controlled conditions using sophisticated measurement
techniques. Participants were young adults aged 18 to 35.
The diets varied in the amount of calories derived from protein.
The low-protein diet had 5 percent of calories from protein, the
normal-protein diet had 15 percent of calories from protein and the
high-protein diet had 25 percent of its calories as protein. All
three diets included the same amount of carbohydrates, and fat made
up the difference in the calories. All participants were overfed by
about 954 calories a day.
Everyone gained weight during the overeating period. However,
people in the low-protein diet lost 2.2 pounds in muscle mass,
while those in the normal- or high-protein groups gained muscle
mass during the overeating period. Muscle weighs more than fat,
which is why they gained more weight. The excess calories turned to
fat among participants who ate a low-protein diet.
The make-up of the weight -- lean muscle or fat -- may be even
more important than the number on the scale or body mass index,
said Dr. David Heber, director of the Center for Human Nutrition at
the University of California, Los Angeles, and co-author of an
editorial accompanying the new study. "Calories count," he said. He
encourages a high-protein, low-fat diet that is rich in colorful
fruits and vegetables. "We are talking about lean protein such as
white-meat chicken, ocean fish, turkey, egg whites and certain
protein powders. Protein is more satiating, and helps reduce
appetite," he explained.
Connie Diekman, director of university nutrition at Washington
University in St Louis, said: "This study provides support to the
calories-count message as it relates to percent of body fat. I find
the conclusion of this study especially helpful in encouraging
people to be aware of the calories they consume and to avoid
focusing on just where those calories come from."
Learn more about
protein at the American Diabetes Association.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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