Mealworms tend to have a higher amount of exoskelton (chitin) in relation to the rest of the insect than other insects. (Now this applies more to regular mealworms (Tenebrio molitor) than King Mealworms (Zoophobas) as they (T. molito) are smaller so they have a greater chitin content). If they are fed in excess there are records of impactions due to the amount of chitin but if they are fed in moderation there shouldn't be any more risk than feeding them most other insects with respect to the impaction..

Ed