Researchers from the Oregon National Primate Research Centre at Oregon Health & Science University who have published a study in the medical journal Human Reproduction have claimed that oral contraceptive pills do not influence in weight gain.

The lead author, Dr. Alison Edelman, M. D. said, "Issues surrounding weight are hard to study in humans, and the research thus far has been insufficient to demonstrate whether or not oral contraceptives cause weight gain or loss."

However, he feels that this is a very significant question as concern about weight gain is one of the main reasons. Due to this fear, women may avoid birth control pills which in turn place them at greater risk for an unplanned pregnancy.

The study took the researchers almost 1 year to come to this conclusion as they studied some rhesus macaque monkeys at their Oregon National Primate Research Centre (OHSU). A rhesus monkey's reproductive system is almost similar to that of a human being.

The study found the following:

The monkeys with normal weight remained the same.

The obese ones lost about 8.5% of their body weight.

The obese ones lost about 12% of their body fat due to higher metabolic rate.

There were no changes in lean muscle mass and physical activity.

So the study is a revelation and an encouragement to those who are keen to have birth control.