Can't say I'm an expert, but I don't think hobbies or other such activities can replace eating too much and/or shitty food. I mean, the typical stereotypes show the opposite: playing console with friends, going out to the movies or to a party, even programming (solitary or "hackathons"), often involve the consumption of loads of sugary soda and other crap. BBQs and similar social meals are often the same.

Hobbies involving exercise may be an exception, but when you're already overweight, these often aren't so much "hobbies" as ordeals, and unlikely to function as any kind of reward.

As someone in the market, it'd help quite a bit if there were healthier and tasty alternatives. Unfortunately, the current offers seem to be expensive and hard to get (if you have to order a whole box over the 'net, forget it).