I do restrict myself for health reasons: I eat nothing with gluten and/or lactose in it (although I have been slacking on the lactose department latey). This is quite restrictive (some would say very), especially because I chose not to substitute with gluten free everything (that for me wouldn't work, I would just long for the real deal more).
So I eat no: pasta, bread, pizza, cereal, buns, pastries, cookies, crackers, most potatoe chips (they are often coated in wheat or contain barley) nor milk, yoghurt, cheese, cream, milk chocolate.
It sounds worse than it is, because I love fruit and veg and I do not feel the need to eat those things most of the time (I do get occasional cravings, but I haven't given in, for a whole 6 weeks!).
However it is "easier" for me to stop consuming those goods because I get physically ill when I do, so when I did "glutenize" a few weeks back (by accident) I got severely ill afterwards (3 nights of diarrhoea and vomiting), so I do nto want to eat them.
Oh I also do not drink soft drinks if they contain gas (I do do the occasional ice-tea), because I get painful bloating from it.
So technically yes I restrict my diet, but I do not feel that I am in as much danger of falling back to the routine and gaining weight because it is for health purposes (also non controled celiac disease leads to intestinal cancer in a huge percentage, and after having seen my mom battle cancer I do not want to have to go through that!),
Camy