Shikamaru would see it as another one of Naruto's troublesome behaviors. He'd sigh and say something like 'What a drag, Naruto. Can't you eat like a normal person?' But deep down, he'd also be a bit intrigued and might end up getting used to it over time.
Sakura would probably be both disgusted and amused at the same time. She might scold Naruto for being so unhygienic at first, but then laugh at his silly antics.
Sakura would be very worried. She would immediately try to find a medical solution, using her knowledge as a medical ninja. She might be disgusted by the worms at first, but her concern for Naruto would override that.
His friends from Team 7, like Kakashi, would feel responsible for Naruto's situation. Kakashi would likely use his resources to find a proper shelter for Naruto. Shikamaru and the others might come together to form a sort of support group for Naruto. They would pool their resources, like money and food, and also try to cheer him up by sharing stories and jokes.
A plot could involve Naruto being cursed by an enemy. As a result, he can only consume food by using his whole body. At first, he's embarrassed and tries to hide it from his friends. But then he realizes that this new way of eating gives him an unexpected advantage in battle. For example, he can quickly consume a large amount of food to boost his energy during a fight.
His friends would be in shock. Kakashi would take charge of the situation. He would gather all the information about what Naruto was doing before he disappeared. Naruto's friends like Choji and Ino would use their respective skills to help in the search. Ino could try to use her mind - reading jutsu on people who were around Naruto before he disappeared. They would all be determined to find Naruto because he is an important part of their team and the village.
Sakura might be initially suspicious. She is a smart girl and would wonder about the butler's intentions. She might keep a close eye on him to make sure he doesn't harm Naruto in any way.
Sasuke might be initially suspicious and keep his distance. He's always been cautious, and this strange new development would make him even more so.
Sasuke, who has his own complex relationship with Naruto, would probably be in denial at first. He's seen Naruto as this strong - willed person, and the idea of him having schizophrenia would be hard to accept. But as time goes on, he would become more protective. He might train Naruto in ways to control his mind during the episodes, using his own experiences of mental discipline. As for Kakashi, he would be empathetic. He has his own traumas, and he would do his best to support Naruto, maybe sharing his own stories of dealing with difficult mental states.
Sasuke might be initially suspicious. Given their complex relationship, Sasuke would likely want to know the real reason behind Naruto's identity change. But once he understands the motives, he might respect Naruto's decision if it's for a good cause.
Sakura might be a bit confused at first. She's focused on her medical ninja training and Naruto's sudden interest in Lunney seems out of left field. But she would probably be supportive in the end, especially if Naruto could show her how Lunney's ideas could be relevant to their lives. Sasuke, on the other hand, would likely be dismissive. He has his own goals and Naruto's newfangled interest might seem like a distraction to him. However, if Naruto could prove that Lunney's concepts could help in their fight against common enemies, Sasuke might change his tune.
Shikamaru would likely be the voice of reason. He would tell Naruto to think things through clearly and help him come up with strategies for dealing with the new situation. Choji might bring over some food to help Naruto out, as he knows how difficult it can be to take care of a child. Ino would be more interested in the child's appearance and would offer to help Naruto with things like shopping for the child's clothes.