Around 80% of the stomach is removed, leaving a tube of roughly 100–150 ml. Here is what that means at the table, month by month.
A gastric sleeve removes roughly 80% of the stomach and leaves a narrow tube holding about 100 to 150 millilitres, against 1,000 to 1,500 millilitres before surgery. That is the whole mechanism: the food that fits at one sitting drops to a few tablespoons, and the region of the stomach that produces most of the hunger hormone ghrelin leaves with the resected portion. Nothing is rerouted, and no device is left inside you.
For the first two weeks you drink — water, thin soup, diluted yoghurt, sipped slowly across the day rather than swallowed in one go. Weeks three and four bring pureed food at roughly 60 to 90 millilitres per meal, six small meals a day. Most patients find this phase easier than they feared, because appetite is genuinely absent rather than suppressed by willpower. The difficulty in month one is remembering to drink enough, not resisting food.
By three months a meal is around 150 millilitres, a small bowl. By a year most patients sit at 200 to 250 millilitres and can manage a normal plate of protein and vegetables if they take their time over it. The sleeve widens slightly and permanently as it heals, which is expected rather than a failure. What must not happen is grazing between meals, which refills the tube repeatedly and quietly cancels the restriction.
Protein first, then vegetables, then anything else, and no drinking for thirty minutes either side of a meal, because liquid washes food straight through the tube and lets you eat far more than you should. We build this into a twelve-month dietitian programme that runs from your pre-operative assessment through your first year, by video call once you are home. Patients who keep those calls hold their result; those who disappear at month four usually do not.
No. The removed portion is gone permanently and cannot regrow. The remaining tube widens modestly over the first two years, which is why portions rise from a few tablespoons to a small plate, but it cannot return to a 1,500 ml volume.
Most patients tolerate small amounts after the first six months, though dense bread and dry rice are the two foods that most often sit uncomfortably. We reintroduce them one at a time with your dietitian rather than banning them outright, because permanent bans tend to end in binges.