Are You Blaming Birth Control For Weight Gain?

MIAMI (CBS4) - Women have long blamed their use of birth control pills contributed to undesirable weight gain; now that theory may have been debunked, according to the South Florida Sun-Sentinel.

In an article set to be published in the February edition of the journal, Human Reproduction, researchers say there is no indication that the contraceptives cause women to tip the scales at their less-than-ideal weight.

To come to that conclusion, scientists and physicians studied a group of rhesus macaque monkeys at the Oregon Health & Science University's National Primate Research Center for nearly a year.

Rhesus monkeys were used because their reproductive system is nearly identical to humans and their food intake was easier to control and monitor than that of a human.

At the beginning of the study, scientists monitored two groups: one group of monkeys that were obese, and the other group that was of normal weight.

During the eight month period, the monkeys received daily doses of oral contraceptives relative to their size and weight, mimicking a similar dosage in a human being.

Researchers carefully tracked the monkeys' weight, food intake, activity levels, lean muscle mass and body fat.

When the study was completed, the normal weight group remained stable, whereas the obese group lost a significant amount of weight (8.5%) and percent of body fat (12%) due to an increase in basal metabolic rate.

"This study suggests that worries about weight gain with pill use appear to be based more on fiction than on fact," said Judy Cameron, Ph.D., senior author of the paper and a researcher at the primate center. "We realize that research in nonhuman primates cannot entirely dismiss the connection between contraceptives and weight gain in humans, but it strongly suggests that women should not be as worried as they previously were,"

The study was funded by the Society for Family Planning.

Source: The South Florida Sun-Sentinel