Hi, I've been through this. I was really overweight and full of toxins, and three years ago began making changes. I reengineered my body, and in the process found that a healthy body had spiritual benefits as well. Other people have already posted all the good nutrition/diet info here. I'll just add a few ideas that worked for me:
1. Completely re-orient your thinking regarding food (others on this thread have said this, but I think it's worth repeating). Think of food in scientific terms. It's not for comfort, it's not for fun, or for a diversion. Food is simply fuel for the body. Would you knowingly put adulterated petrol in your car? Would you overfill the tank? Do they sell strawberry and caramel flavored petrol? If not, why do we subject our bodies to such things? This doesn't mean you can't enjoy good tasting food. But it has to be in moderation. Whenever I want to grab a chocolate eclair because I'm distressed, I take it as a warning that something is amiss and I need better meditation.
2. Alcohol is not conducive to weight loss (see: http://christianfinn.com/alcohol-weight-loss/
). I was unable to lose my final 2.5 kg of excess fat until I went totally dry. After two months of no alcohol, it was all burned away. Whether to chose moderation or total abstinence is each person's decision. I'm just saying that going dry will really drop the kgs.
3. The best fitness regimen on the planet has been historically intertwined with Theravada, and its techniques passed along via monasteries: Muay Thai. Regular Muay Thai workouts lead to optimum fitness. If it's possible, spend a month in Thailand in a Muay Thai camp. Buy the genuine equipment there and take it home, set up a kick bag in your garage, and make it a part of your life. If so, excess weight will soon be a thing of the past.
(If anyone requests, I can recommend the best Muay Thai gyms/camps in BKK, and a few in south Thailand also).
Again, I've been through this and I know the despair of being overweight and unfit. If there was hope for me there's hope for anyone. Even if Muay Thai isn't an option, there are regimens like Insanity, etc. that will do the job.
P.S. I've never seen a fat Buddha image in Thailand. They're all lean. My good friend in Krabi likes to run up the thousands of stone steps to a nearby Buddha shrine, and by the time he's reached the top he's had more than a day's workout. He refers to the austere Buddha statue at the top as "The Fitness Buddha." I'm still an outsider; I haven't even officially taken refuge yet. But I know that Theravada and fitness go together quite well.