Why would a person be underweight with less villi than normal?

A person with fewer villi in the intestines may be underweight due to impaired nutrient absorption. Villi are tiny finger-like projections that increase the surface area for absorption of nutrients from food; when they are damaged or reduced, the body cannot effectively absorb essential vitamins, minerals, and calories. This malabsorption can lead to nutritional deficiencies and weight loss, as the body does not receive the necessary energy to maintain a healthy weight. Common conditions that reduce villi include celiac disease and certain infections.