@Dulcet
I have a feeling the description was mistranslated. The original was probably something along the lines of '2% of the people in the world' rather than '2 people in the world.' You're also correct in that the MC's symptoms don't seem to be consistent with bulimia. Bulimia is characterized by binging and purging. As such, patients with bulimia typically present as malnourished and at no more than regular weight. The MC's symptoms are more consistent with a primary diagnosis of binge eating with possible secondary bulimia if he purges occasionally.
As to your issues with my earlier post: When you introduce someone to a new therapy, you let them know the risks and expected outcomes (essentially, informed consent). Even with art therapy, you'd tell the patient the point of the therapy before handing them a coloring book, and you'd check their progress to ensure that the regimine is working.
In contrast to a properly supervised course of therapy, the MC is allowed to use the VR pod as much as he wants in any way he wants without supervision, guidance, or followup. At no point did his therapist broach the subject of his behavior in the game in regards to his unhealthy relationship to food. There was a single, superficial conversation and nothing more. This is a manga, not a therapy training manual, so I don't expect a perfect recreation of a proper therapy session, but this doesn't even come close.
Even if the therapy were realistic, we're putting the cart before the horse. The issue with the realism of his therapy is secondary to the story and characters. The story and MC would still suck even if the therapy were more realistic.