I'd try eliminating one thing you eat for a week at a time and see if it make a difference. Good things to try are dairy products, fatty items, and gluten containing foods. (Gluten is everywhere, so you'll have to do some research.)
I feel better when I eat a low fat, high fiber diet with a large quantity of vegetables. I definitely eat more than 5 servings a day of veggies. Even just replacing your normal lunch with a chef salad could make a big difference (as long as you don't load it up with cheese, bacon and ranch like my brother likes to do.) :-)
Good luck and congratulations on 70 pounds lost!