HI, thanks for using healthcare magic You may want to make sure that your thyroid levels are normal on the replacement hormone. If they are low , it would contribute to your weight gain. It can be difficult to lose weight. It is good that you are active. Exercise and activity help in general fitness, heart health and to maintain weight loss but it is actually easier to lose weight by changing diet. Medical studies have shown persons lose weight easier with diet changes. The exercise helps the diet but activity on its own would not be very effective. There are two main types of diet low fat/low calorie diet and low carbohydrate diet. Both cause weight loss, the low carb causes fasting initial loss. They would both involve using alot of water, eliminating sodas and fruit drinks as well as high calorie deserts and pastries. There are differences after this point. Low fat involves eliminating fat by using low fat cheeses/milk/dressings, avoiding frying, lean meats, increasing fruits and vegetables. Low carb would involve reducing carbohydrates because carbohydrates cause the body to release insulin and insulin stops fat from breaking down. It involves eliminating rice/pasta/some breakfast cereals/biscuits/bread/potatoes/flour products, eating any amount of protein. You can determine which is best for you I hope this helps