How can i prevent weight gain while on birth control pills?

Good nutrition: Although the oral contraceptive pills do slightly affect thyroid levels by increasing thyroid binding globulin the minimal dosage of the pill no longer causes "estrogen bloating and water retention, a leading cause in weight gain. Eat a proper balanced diet, exercise, and get plenty of sleep and you will not "look like the stay puff marshmellow man".

Exercise: 1 hour of exercise a day and eating 5 serving of fruits and veg's a day with appropriate proportion size of main servings.