What do you eat after weight loss surgery?

If you are considering the surgery, why are you asking if you can get the same results following the same diet? Surgery is the last option for those who are seriously overweight, and ALL other methods have failed. It sounds like you want to try and change your diet, which is good. If you have not tried diet and exercise, then you should. This surgery is dangerous, and full of risks.
Spend the time exercising and eating healthy food. It took a long time for you to put on the weight, so it is going to take a long time to take it off. Just be patient and you will be rewarded for your efforts.
They give you very strict instructions about what you can, and cannot eat after surgery. For instance, you cannot drink and eat at the same time. You cannot eat anything that contains huge amounts of sugar, or fat. At first you are limited to a liquid diet, then you are allowed things like jello, or other soft foods.
You must also consider the consequences of having this type of surgery done, not just short term, but think long term, in the future. The majority of people who have this surgery do have some sort of complications, and they do gain a lot of the weight back. If you have not addressed the emotional aspect of why you overeat, this is probably not the best option for you.
Weigh your options carefully, and make a VERY educated decision. Speak with many people who have had this done. Ask them all kinds of ?’s. I know many people who have had this done, and sure it gives you the results you want very quickly, but for what they have gone through, it isn’t close to being worth it. Good luck.