A year and a half ago I underwent Gastric Bypass Surgery and lost 176 lbs. At the same time, I gave my friend alot of the tips that the nutritionist gave me- and she lost 50 lbs (without surgery). I was told to always eat foods that have 5grams (or lower) of both sugar and fat. Also, no white bread or pasta. Eat lots of protein (keeps you full longer) and fruits and veggies. There are lots of sugar free/fat free foods out there (even oreo's!). You can even buy protein poweder and add fruits to them to make a smoothie. And also walk..walk..walk. Good Luck!
Check out the 17 day diet book. It works and is just good clean eating. As for exercise, I walk. I know everyone’s pain levels are different, but just do what you can do. At first I couldn’t walk very far and yes I felt it the next day. Now I have increased my stamina and am walking 1 mile sometimes 2 a day. So far I have lost 17lbs in 31 days.
This seems to be struggle for many. Pills are never fun, but if they help maybe worth a try. Good luck to you and take care.