What's the purpose of intestinal villi? It provides macro and micro-nutrient absorption, right? For reference: Macronutrients are the ones you see on food labels: proteins, carbohydrates, and fats. Micronutrients are vitamins and minerals (vitamins A, B, C, D, E, and K. Nutrients like iron, magnesium, calcium, and so on).
So if a person has fewer of them, that means that they absorb nutrients at a slower rate.
Macronutrients have energy values, expressed in Calories (side note: always capitalize the C, or note them as kcal, because a Calorie is 1,000 calories... don't ask me why that is because I don't know). If you're absorbing fewer Calories than you're expending, you won't gain weight.
Therefore, I'd expect these people to be underweight.
