7. Sugary Treats
Processed sugars are the most harmful substance that we usually overeat without even realizing it. Sugar is said to be the main factor behind weight gain, inflammation and it also increases the risk of issues like tooth decay, diabetes, and heart disease.
Your metabolism slows down considerably when you have an underactive thyroid which can lead to weight gain. If you keep eating more sugar during such a condition you will put on a lot of extra pounds.