The thing I'm going to do (starting right after Christmas) is a low-carbohydrate diet...it doesn't allow refined sugars and grains, but it does allow (depending on the kind of low-carb diet you're doing) most, if not all, dairy product, ALL nuts (Yum, I looove nuts.) most fruits, most veggies, (not potatoes, though.), and then any kind of non-breaded, non-glazed, etc. meats. Pretty much a wide-range diet. So you don't have to buy any special foods besides natural foods, no pills, not too many restrictions (the sugar/grain/starch restriction might seem strict...but since you can eat plenty of fruits and definitely most veggies, you're good to go. I'd recommend berries if you don't want to eat a fruit higher in sugar than most fruits.). I don't really think going low-carb is much of a diet, though...just a better, more natural way of eating.
Btw...if you tell me that grains are important to a balanced diet, not mine...I have a wheat sensitivity. So I don't trust all that in my diet. And I'm a really bad sugar-junkie. So it'd be best for me to stay away from most of it...so I basically gotta be on a low-carb "diet."