Hyperthyroidism may cause a decrease in weight, but hypothyroidism--slow thyroid function--can increase weight despite efforts to lose a portion of it. The slow thyroid function can decrease TSH levels and slow down metabolism. This can also set a higher weight set point, which the body tries to reach to maintain a standard weight.
So what's the best weight loss product for thyroid problem sufferers? There is none. The best course of action is to first have your thyroid tested, then consult with your doctor on how you can deal with losing weight despite hypothyroidism.
There have been many supposedly "thyroid cures" for overweight men and women. One such touted cure is Dr Siegel's Cookie Diet. However, experts say having less than 800 calories per day may not be safe for your health.
Another possible solution is the use of CLA, or conjugated linoleic acid, which doctors have proven to have some effect in suppressing appetite among thyroid problem sufferers and still be safe for their health.