I've lost weight over the past few months (Jan - present), but I don't diet. Before, I just ate whatever I wanted - two bags of Doritos (1000 cals each!), a pain au chocolat, a chocolate bar, a take-away pizza - yes, I could eat all of that in one day, and nothing else. Proper binging. I never became fat, but I noticed I had become 'podgy' around my face and was constantly bloated. Now, I eat sensibly, watch how many calories I consume (1500 - 2000 is ideal), but I don't deprive myself of the foods I love, I just eat them in lower amounts, and I have a junk day - Saturday, as this is the day I go shopping, and I get paid on Fridays, so it's the perfect chance to just 'let go'. Only one day, two at the most, and it's worked for me. I still manage to have a junk snack every day, such as a packet of crisps, or maybe some chocolate, but nothing excessive. I could never go on a proper diet, they make me feel depressed (more so than usual).
Oh, and I've started exercising again. I actually enjoy breaking a sweat, but I do it in the comfort of my own home as I'm too self-conscious to go to a gym.