
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: FRIDAY, April 13, 1990                   TAG: 9004130073
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A4   EDITION: METRO 
SOURCE: The New York Times
DATELINE:                                 LENGTH: Medium

WEIGHT REGAIN, ENZYME LINKED

A change in body enzymes may be one reason that many people who lose weight quickly regain it, according to a new study.

Researchers found that when obese people lost weight, they started overproducing an enzyme that makes it easier to get fat again. The enzyme helps plump up fat cells that were deflated by dieting, allowing fat to be stored once again in body tissues.

The effect of these high enzyme levels is to make weight gain far easier for the formerly obese than it is for people who were never fat to begin with, the researchers say.

And the fatter the person was to begin with, the more of the fat-regaining enzyme they produced once when they were thin.

The study, of nine extremely obese people by Dr. Philip Kern of Cedars Sinai Medical Center in Los Angeles and his colleagues, was published Thursday in The New England Journal of Medicine.

It could eventually be possible to "figure out how to block the brain from telling fat cells to increase their enzyme activity," said Dr. John D. Brunzell, a professor of medicine at the University of Washington in Seattle, who also has studied the fat-depositing enzyme.

In his study, Kern followed the nine people, who dieted, lost an average of about 90 pounds and kept the weight off for three months.

The researchers measured levels of the fat-depositing enzyme, lipoprotein lipase, before the people started their diets and after they had been at their new low weights for three months.

The researchers found that the enzyme levels were consistently higher when the people were thin than when they were fat. Also the fatter the people were to start with, the higher their lipoprotein lipase levels were after they had reduced.

One way of explaining this is to consider the idea of a set point, said Dr. Kelly Brownell, who is a director of the obesity research clinic at the University of Pennsylvania School of Medicine. A set point is the weight that a person, for unknown reasons, seems to gravitate toward.

"If you believe in set points, it's not hard to imagine that the body would defend itself against weight loss," he said.

by CNB