I've been diagnosed with hypothyroidism. i follow a good diet and exercise and my metabolism has been checked and its fast. hard to lose weight still?

Exercise: If thyroid functions are normal and calories are not to excess, perhaps the frequency of exercise needs to be increased.

Check bmr: With hypothyroidism and difficulty losing weight, have your T3 (liothyronine) checked since that can be a problem. Alsoyour resting metabolism rate can be measured in weight loss clinics that will explain what your true metabolism rate is and from that decrease your calories by 500cal/day to lose one pound per week. Drink water since that helps with weight loss.