Is there really a connection between birth control and weight gain? In one recent survey, 50% of all women felt that birth control pills would cause unwanted weight gain. Of these women, 20% said this belief was the primary reason they would not use oral contraceptives. There are also evidences that women switch methods or birth control or stop using the pill because they think it contributes to weight gain. However, the good news is that the review found no evidence to support a casual association between combination contraceptives or birth control and weight gain.
Researchers have found it difficult to prove a connection between birth control and weight gain. While many women do gain weight after starting the use of oral contraceptives, it’s hard to tell if this weight gain is actually caused by the use of the pill or other lifestyle factors. In most cases, women taking oral contraceptives report a weight gain of five pounds or less. Only a small percentage of women experience a weight gain of more than 10 pounds after beginning a birth control pill prescription. Supposedly, any weight gain or weight loss related to the use of birth control pills is a side effect that will happen within three months of beginning of the prescription. Some studies have shown that while the pill may add a couple of pounds at first from water retention, the added weight disappears as the body adjusts to the hormones.

Another study found no difference between women who took hormonal contraceptives and those who took a placebo. The other studies looked at women taking different types and doses of hormonal contraception, and came to the same overall conclusion.
The claim may have had some truth many years ago, when the pill contained high levels of estrogen, hormones that cause water retention and increased appetite. Nowadays, most versions of the pill have only half the amount found in early versions.
There is also another factor that has nothing to do with the pill. It is a fact that most women in the Western world start birth control as teenagers and continue it through their 20s, a period when women naturally tend to gain weight. In addition, it is possible that women who expect to gain weight after starting on a birth control pill prescription are unconsciously changing their diet and exercise habits. However, if a woman has tried several different types of birth control methods and had no success in controlling unwanted weight gain with diet and exercise, she may want to ask her healthcare provider if insulin resistance is contributing to her problems. A simple blood test will be able to determine the presence of this condition. If a woman is suffering from insulin resistance, a low carbohydrate diet may be necessary to stabilize her weight.
Any weight gain after starting pills of more than 5% of body weight may be a signal of a woman's tendency toward insulin resistance or abnormal glucose metabolism. With this amount of weight gain associated with an oral contraceptive, a woman should be evaluated for possible insulin resistance. If this condition is present, she will have to adopt a low carbohydrate diet. Simple sugars in any amount and high carbohydrate only snacks or meals will negate all other dieting efforts on a daily basis and frustrate any long term ability at weight control.
In most cases, unwanted weight gain associated with birth control can be prevented by paying extra attention to diet and exercise or simply switching to a different type of birth control. The link between birth control and weight gain can sometimes be exaggerated, and it's about time to break those myths.