Fluoride is thought to interfere with proper thyroid functioning. Use toothpaste that does not contain fluoride. These may be hard to find nowadays but there are some available in natural health food stores if you can not find them at the grocery store. Use a water filter if your tap water contains fluoride. Just removing the fluoride from drinking water will be extremely beneficial and helpful to your thyroid health. A properly functioning thyroid will help control weight gain and even lead to a natural and effortless weight loss. This in turn gives you more energy and the desire and drive to exercise more. This is a good catch 22 to be in. Not only is the circle continuing to give positive energy to your tired cells, but it promotes weight loss too.