It is primarily the thyroid gland that sets your metabolism rate. An underactive one can result in weight gain and less energy. Lack of Iodine has been found to be a leading cause of underactive thyroid. There are other causes. But moderate levels of iodine in your diet is important as your body doesn’t produce iodine on its own. Unless you have a fairly high intake of iodized salt daily or you eat a lot of seaweed, you may be starving this important gland of a vital nutrient for its optimal performance. Without enough iodine your body cannot produce enough of this ever so important hormone and it can be affecting your metabolism.
Here’s a very good article on the subject with even more information:
Kelp is a natural source of iodine. Since chewing on kelp isn’t too tasty, you can get ground kelp in capsules quite inexpensively. I recommend taking 1 or 2 kelp capsules a day. You won’t get any instant jolt of energy from it, but over time a more nourished thyroid will perform better and might just help with improved energy and easier weight loss.