The expenses for weight-loss programs may be deducted as a medical expense. In order for uncompensated amounts paid by individuals for participation in a weight-loss program to be deductible, the program must be for treatment for obesity diagnosed by a physician. But you cannot include the cost of a weight-loss program if the purpose of the weight control is to maintain your general health.
The costs of meal replacements, diet foods, and supplements are nondeductible personal expenses. The amount you can include in medical expenses is limited to the amount by which the cost of the special food exceeds the cost of a normal diet.
No portion of membership dues paid to a gym, health club or spa qualifies as a deductible medical expense in any case—even if the individual joined on the advice of a physician to lose weight to combat a disease.