Since my health has been going so well, and I'm enjoying what that feels like, I'm trying out a vegetarian diet. As much as anything, it's to force myself to eat more vegetables, as my tuna and rice habit made me lazy in my food preparation, settling for tinned and processed goods.
So far, over 10 days with no meat, I'm still feeling really good. Coping fine with full work weeks, partying till 2am on Saturday in the cold, and my regular walks. Compared to my gluten-free diet, it's actually a breeze.
I've known for a long time what I need to do to be healthy, but have simply fooled myself into thinking I don't have time, or energy, or whatever, to do those things. Walking is one, getting rid of Coke is another (10 weeks and counting without a drop of cool, black gold). I've had almost no red meat for 2 years anyway, so cutting out chicken and tuna was the next step to try, and not much of a burden (so far).
So even if I don't stick with "cold turkey" (reverse no-pun not intended), I should at least have supplemented my diet with appropriate amounts of veges, and will eat less meat.