Iodine plays a major role in regulating thyroid function, in turn supporting a healthy metabolism and growth. Unfortunately, many adults don’t consume enough iodine-rich foods to begin with; but then move in “diets” in an attempt to lose weight and further restrict their intake of iodine rich foods.  An area of particular interest is the reduction in T3 during low carbohydrate and low calories diets in an attempt to prepare for a bodybuilding/physique contest or when cutting calories to lean out. When dieting one of the overlooked elements is metabolic adaptation.  In a low caloric state that is also low in carbohydrates we tend to see a large reduction in the production of T3. Generally carbohydrate rich foods and sodium rich foods get removed from a person’s diet as they move further along.  However, removing sodium too soon and/or not supplying the body with enough iodine can be detrimental to your progress and your metabolism.   That being said this study support no effect from iodine supplementation during the diet.  Leaving us to wonder if stimulation from carbohydrate intake is more important.


Reinhardt W. et al (1993) Effect of small doses of iodine on thyroid function during caloric restriction in normal subjects. Retrieved from: