Yes, if eaten in large quantities they can cause a blockage in the intestines. Mealworms have a tough 'chitinous' exo-skeleton which is difficult for the cham to digest in large quantities. That is why it is recommended that mealworms are fed sparingly and as treats rather than be used as a staple food item. Amy loves them too, but she only gets a couple every few weeks as a treat and then I only give her the newly moulted white ones.
Super worms are a better alternative than mealwomrs as they have more meat to them, but make sure that your cham is big enough to eat them!