Exercise and diet combo may help Hard-to-Gain weight women build muscle

This study tests whether a program of adapted physical activity combined with extra nutrition can help women with constitutional thinness gain lean body mass (muscle). Constitutional thinness is a condition where people are naturally very thin and find it hard to gain weight, even though they are not malnourished. The study will enroll 62 women aged 18-50 with a BMI of 18.5 or less and stable weight. Participants will follow an exercise and diet plan, and researchers will measure changes in muscle mass, BMI, and energy balance.