Several folks have reported being able to lose weight after a series of liver/gallbladder flushes. Unexplained weight gain can have a number of causes, though. As far as I know, the most common is low thyroid (hypothyroid).
It may be worth checking this out with a physician who is willing to aggressively supplement thyroid hormones, typically T4 and T3. Minimal tests would normally be at least TSH, free T4, and total T3.
Some doctors will not supplement thyroid hormones if your test results don't fall below the bottom of the reference range (don't exceed the upper range). Check with the head nurse before going in so that you don't waste your time, money and emotional reserves on a doctor who isn't experienced with modern methods of testing and treating thyroid conditions. Many are not. Ask friends for a referral, or use the yellow pages until you find one that you're comfortable with.
Reference books you may wish to investigate for background information:
Richard L. Shames, M.D., Thyroid Power
An excellent primer on understanding the symptoms of thyroid disjunction, what tests to get, interpreting test results, and treating various thyroid conditions. If you're only going to look at one book, this is probably it.
Stephen Langer, MD, Chronic Fatigue, Fibromyalgia and Environmental Illness, pp. 166-172
Excellent background information. For treatment he concentrates on natural thyroid hormone supplements. These are derived from hog thyroid glands, which are a turn-off for me because of my cultural background and my concern over potential viral or other contamination. It's possible to mimic his treatment protocol by supplementing with synthetic T4 and T3 if you're not comfortable with natural thyroid hormone supplements.
Jacob Teitelbaum, MD, From Fatigued to Fantastic, pp. 44-47
He's one of the leading experts on chronic fatigue/fibromyalgia. While not perfect, on the whole this may be the best book on these subjects.
Good luck in your journey! Let us know where it takes you...
hg