ok, here what i did...
a little bit ago, i needed to lose around 10 lbs to get down to race weight for swimming. Instead of going on some elaborate diet I did 4 things:
1. no more junk food
2. drink a big cup of water before every meal
3. bought smaller plates and bowls (this limited portion size)
4. stopped eating after 9pm.

i kept everything else in my life pretty much constant, and lost the weight in about 1.5 months (slow, but it came)

i'm not saying that this will work for everyone, and it sure hasnt helped now that i stopped exercising (back up where i was before), but it seems to me that a healthy diet and exercise will keep much of the population where they need to be.