Maybe if he'd had a bit more soupy and a bit less biscuit..
Indeed. Do we know how he is obtaining his food.? Though, it can be easy to oversimplify that angle (controlling his food source) - it reminds me of documentaries where even in obesity clinics patients are getting hold of junk food. There are all sorts of possible issues involved, as with other addictions - manipulation of friends/family, misguided relatives, dependency, denial, the knowledge they will find some other way anyway - it probably sounds more straightforward than it is, like many situations viewed from the outside.