Hi. Ideally with the four medicines - namely Rifampicin, Ethambutol, Isoniazide and Pyrizinamide you are taking should have increased your weight. If the weight is not improved in spite of improved appetite there are chances of the following not allowing you to gain weight: -Blind loop syndrome, wherein a part of the intestine stops acting as a absorbent of the nutrition. -Low hemoglobine and low serum proteins- -Resistance tuberculosis. I would suggest you the following ...:: take supplements under your Doctor s guidance -Take anabolic steroids under Doctor s supervision -Get yourself reviewed by a Gastroenterologist. -investigations : Blood , urine and stool Enteroclysis to get a proper diagnosis and The answer may be surgery to correct the problem.