Ok, Ill take a stab at it. I recently had to make drastic diet changes bc of an auto immune disorder that got out of control about 4 years ago. Here is what I did:
1. Change to a partial-vegetarian diet. Eating meat is fine but you have to limit your consumption and focus on the right types (organic, free range, etc.). Which is great bc most meat produced in the US is EXTREMELY toxic for you to eat. I eat 2 meals a week with chicken and that's it. No Red meat. No seafood of any kind. Both are toxic.
2. Try and get away from white flour, white sugar, and most of all HIGH FRUCTOSE CORN SYRUP. Read the labels you will be shocked at what has HFCS.
3. No fast food of any type, the food they use is not really food and causes major problems.
4. Eat "food" only, not processed food. The rule of thumb is if you cannot understand the ingredients, don't eat it.
5. Do some form of Yoga. I prefer power yoga, but any is fine.
You have to change your entire way to thinking about food and exercise. Food is fuel and exercise is to keep your body at peek performance.
I lost 77 lbs in a half of a year doing this. I am now 6'4" 230(roughly, I don't weigh myself any longer bc its not the point of changing.)
If you follow these rules, you will lose weight and keep it off easily. Focus on being healthy and eating the right things and you will lose weight.