Why Do High-Protein Diets Work?
Lose more weight when you eat lean, red meat
May 9, 2003 Carnivores, rejoice! Red meat might be key to your
high-protein diet. That's the finding from a new study, presented at an annual
meeting of the American Heart Association.
"This is notthe Atkins diet," says lead investigator Manny
Noakes, PhD, a research dietitian with the Commonwealth Scientific Industrial
Research Organization in Adelaide, Australia. "This is a high-protein diet,
but it includes more fruits and vegetables than Atkins," she tells
The Atkins diet, which has drawn criticism from dietitians, is a
high-protein diet but allows few carbohydrates (at least in the first few
weeks). Later, dieters are allowed to gradually add in limited amounts of
fruits and vegetables. Atkins allows too much saturated fat and is too skimpy
on fruits and vegetables, many dietitians say, but research has shown that
people on the Atkins diet do lose weight without upping their cholesterol.
In their study, Noakes and colleagues set out to analyze red meat's effects
-- very lean red meat, that is -- on risk factors for heart disease and
diabetes, she explains. However, the results turned up a surprising
But first the data: 100 women were enrolled in the study -- all overweight,
with an average body mass index (BMI) of 33. For 12 weeks, half the women ate a
high-protein diet of 34% protein, 46% carbohydrate, and 20% fat. The other half
ate a high-carbohydrate diet that was 17% protein, 63% carbohydrate, and 20%
fat. Each diet consisted of about 1,340 calories, and protein in both diets was
from lean red meat.
Who Lost More Weight?
After 12 weeks, both groups lost weight -- but some of the high-protein-diet
women lost substantially more weight. Those women who had triglyceride levels
higher than 133 mg/dL -- a fat in the blood -- at the study's beginning lost
25% more weight, reports Noakes. At the study's end, the high-meat eaters also
had 22% lower levels of triglycerides, she says. High triglyceride levels are
often seen in people at risk for diabetes.
Other measures of health -- "good" HDL and "bad" LDL
cholesterol, blood sugar, and fasting insulin levels -- fell in both
"You can lose weight in lots of different ways," Noakes says.
"But certain people might do better on a certain dietary pattern with less
carbohydrates, more protein. They will feel less hungry, be able to tolerate
eating less for longer periods of time. We find that's generally true of
Whether or not you have high triglyceride levels in your blood, this type of
red meat, high-protein diet might work for you, she adds. "It's whether or
not a particular pattern suits you. A high-carbohydrate diet -- rice, pasta,
fruit, vegetables -- hasn't always worked for people. There are lots of
strategies to lose weight, and this is one of them."