There are two phases to weight loss surgery. I had RNY gastric bypass surgery and I transitioned from the Weight Loss phase to the Maintenance phase at around 7 months. But it also depends on the type of surgery. Some individuals with the sleeve generally get there in up to 2 years. And it depends on who much weight you have to lose and your own body chemistry.
For those with gastric bypass, you body changes physically. After surgery, the part of your stomach that process fats and sugars has been cut away and these substances will quickly pass out of your stomach and into your intestines which does not know what to do with them. That is why your surgeon restricts your diet to eliminate or minimize these. But after several months, you intestines change and learn how to process these substances. Around this time hunger returns. It is not as strong as before surgery, but the honeymoon period is over.
Anyways if you had gastric bypass, you may be transitioning into the Maintenance phase. The strategies are different between these two phases, so you must adjust accordingly. Anyways this is my impression of the Maintenance phase. http://www.breadandbutterscience.com/Surgery2.pdf