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HIGH-PROTEIN DIETS MAY AFFECT YOUR MOOD (3/5)
BY JACQUELINE STENSON
c.1996 Medical Tribune News Service
WASHINGTON - Low-carbohydrate, high-protein diets may be
self-defeating - and bad for your psychological health as well, new
The reason: people who eat low-carbohydrate, high-protein diets
to lose weight often become tense or depressed, and end up turning
to carbohydrate-rich fatty snacks, a Boston researcher reported
Low-carbohydrate foods trigger a change in behavior through a
chain of chemical events in the brain: the reduced absorption of
the amino acid tryptophan into brain cells decreases the levels of
serotonin, a chemical that affects mood, reported Judith J.
Wurtman, head of the Nutrition and Behavior Studies Group at the
Massachusetts Institute of Technology Clinical Research Center in
Low serotonin levels, in turn, cause people to feel irritable,
anxious and depressed, which causes them to crave high-carbohydrate
foods, Wurtman reported here Monday at a conference on obesity.
On the other hand, diets that are high in carbohydrates and low
in protein help increase brain serotonin levels, thus helping to
improve mood and appetite, she said.
Low-carbohydrate, high protein formulations are the basis of
many commercial liquid diets, she noted.
In an ongoing study of 40 obese women who had a long history of
diet failure due to stress-related overeating, Wurtman found that
those who consumed a 1,400-calorie, high-carbohydrate, low-protein
diet reported significantly fewer cravings and better overall moods
after seven weeks than those who followed a high-protein,
low-carbohydrate diet totaling 1,400 calories.
The women on the high-carbohydrate diet also lost significantly
more weight by the end of the study than the high-protein diet
group, she said. The high-carbohydrate group lost two to nine
pounds, whereas the other group either lost fewer than two pounds
or actually gained weight because they indulged in
``Since tryptophan uptake in the brain is associated with the
synthesis and release of brain serotonin, and since serotonin
regulates both carbohydrate appetite and mood, this dietary
intervention may be useful in controlling stress-generated
overeating,'' she said.
A better understanding of what causes overeating is necessary to
solve the obesity problem in the United States, where 30 percent of
the population is overweight, Wurtman said.
About 99 percent of people who complete a weight-loss plan in
this country gain their weight back within five years, she said,
adding that low levels of carbohydrates in many weight-loss
regimens may explain this widespread failure.
Women who experience premenstrual syndrome and people with
seasonal affective disorder - conditions that share mood states
with stress-related overeating - also often crave carbohydrates,
according to Wurtman. ``The consumption of carbohydrate-rich food
is an attempt by such people to make themselves feel better,'' she
But when people crave carbohydrate-rich foods, they probably
also crave high-fat foods, said Patrick M. O'Neil, director of the
Weight Management Center and professor of psychiatry and behavioral
sciences at the Medical University of South Carolina in Charleston.
Otherwise, they would crave fruits and bland carbohydrate-rich
foods, rather than chocolates and sweets, he said.
So the role carbohydrates play in weight control may be
``overstated,'' O'Neil said. A pleasant tasting food also can make
people feel better, he said.
In addition, most people who are dieting do not report
dieting-induced depression or other mood swings, he said.