Anyone who talks about the fact that a number of kilos have fallen on their hips again and blames the thyroid gland usually gets a weary smile. A lame excuse? no way. An underactive thyroid can actually contribute to rapid weight gain even though eating habits have remained unchanged. It is mostly women over the age of 40 who struggle with an underactive thyroid . However, this can also occur in men and young women. This small gland sits just below the larynx and looks like a small butterfly. The thyroid controls the metabolism, heat and energy balance by releasing hormones T3 and T4. The thyroid needs iodine and protein to function properly. The body cannot produce iodine itself, so it must be ingested through food so that the metabolism transports the iodine into the blood. The metabolism is more active, the more hormones are in the blood. If the thyroid gland is underactive , too few thyroid hormones are sent to body cells and metabolic activity decreases. With an underactive thyroid, no one is inevitably doomed to be overweight. Many of those affected are of the opinion that the fight against obesity remains hopeless. The mechanism for losing weight is literally blocked and the conviction of losing kilos after a diet and gaining them again is retained.