|
High-Protein,
Low-Carbohydrate Diet
Plus Exercise Equals More Weight Loss
Women who follow a high-protein, low-carbohydrate
diet may lose more weight and body fat, particularly when they
engage in regular exercise, than those whose diets are low in
protein and high in carbohydrates, a team of Illinois researchers
reports.
"A protein-rich diet, restricting carbohydrates, is a very good
way to lose weight," study author Dr. Donald K. Layman stated.
And, he added, "It definitely enhances the benefits of doing exercise."
Yet, both a high-protein and a high-carbohydrate diet are effective
for women who desire to reduce their cholesterol level or otherwise
improve their blood lipid profile, the report indicates.
A growing body of research points to the benefits of low-calorie
diets that are low in carbohydrates and high in protein. Regular
exercise is also known to be both a necessary component of any
effective weight loss strategy and key to the maintenance of that
weight loss. Yet, few researchers have examined the combined role
of a high-protein, low-carbohydrate diet and exercise in weight
loss and body composition.
To investigate, Layman, a nutrition professor at the University
of Illinois, in Urbana, and his team studied 48 women, aged 40
- 56 years. The women were randomly assigned to one of four groups:
a high-protein diet group, a high-protein diet group that exercised,
a high-carbohydrate group and a high-carbohydrate group that exercised.
[
The diets were equal in total energy, and were both "nutritionally
sound," the researcher noted, allowing the women to consume recommended
amounts of fruits, vegetables and dairy products, while controlling
their servings of protein and carbohydrates, respectively.
Those who exercised were required to walk for at least 30 minutes
a day for five days a week and to participate in a resistance
training program twice a week, using weight machines.
At the end of the 16-week study period, women in all four groups
lost a significant amount of weight, lost body fat and reduced
their calorie intake, Layman and his team report in the Journal
of Nutrition.
However, those who consumed the high-protein diet lost more body
weight and total fat and less lean muscle mass than did those
on the high-carbohydrate diet, the report indicates. Further,
the addition of exercise, particularly to the high-protein diet,
allowed women to lose even more body fat and preserve lean mass.
For example, women that consumed a high protein diet and exercised
reduced their body fat by 21.4 percent, while those on the high-carbohydrate
diet that did not exercise experienced a 12.8 percent drop in
body fat, study findings show.
Both the high-protein and the high-carbohydrate diets improved
the women's levels of blood fats, but the effect varied according
to the specific diet, the researchers note.
The high-carbohydrate group experienced greater drops in their
total cholesterol level and their level of the "bad" LDL cholesterol,
while the high-protein group experienced greater drops in their
level of triacylglycerol and maintained higher levels of the "good"
HDL cholesterol.
Both diets "improved (the women's) profile but they were a little
different in how they improved it," Layman noted. Thus, in answering
the question of which diet works best, Layman emphasized that
it "depends on who you are."
Women with high levels of triglycerides and low levels of HDL
cholesterol, such as those with the pre-diabetes metabolic syndrome,
may gain the most benefit from a high-protein diet, for example,
while those with high cholesterol may gain more benefit from the
high-carbohydrate diet, the report indicates.
The research was funded by the Illinois Council on Food and Agricultural
Research, the National Cattlemen's Beef Association, the Beef
Board and Kraft Foods.
More articles on low
carb diets
SOURCE: Journal of Nutrition, August 2005.
Reference
Source 89
September
13, 2005
For
more information on how to prevent other diseases, use
PreventDisease.com's "Quick
Prevention Resources".
|
