It is completely normal to go through periods where weight loss slows down after gastric sleeve surgery. These “plateaus” can feel frustrating, but they usually have clear explanations. Often, the issue is that eating habits have not fully adjusted to the smaller stomach. Good dietary support before and after surgery helps set realistic expectations and prepares you for these phases. If your weight loss is not progressing as expected, one or more of the following reasons may be involved.
1. You are not eating enough
It may sound surprising, but eating too little can stall weight loss. After surgery, levels of the hunger hormone ghrelin drop sharply, so you often do not feel hungry. Combined with a much smaller stomach, reduced to around the size of a banana, many patients unintentionally eat far too little.
When the body receives too few nutrients, it starts breaking down muscle along with fat. The less muscle you have, the slower your metabolism becomes, which makes further weight loss harder. This is what leads to the well-known plateaus.
How much you should eat depends on how long it has been since your surgery, and your dietitian will give you a calorie target for each stage. In the early weeks, calories are not the priority. As you move on to more normal foods, your target gradually increases. Eating consistently below your target slows weight loss in the long term.
2. Your diet is unbalanced
Once you are at least four weeks past surgery, it is important to include solid protein sources and healthy fats at each meal. In line with BOMSS guidance, UK bariatric teams usually recommend 60 to 80g of protein a day, though your dietitian may adjust this for you.
Protein matters because it protects your muscle, keeps you fuller for longer and supports steady weight loss. If your meals are low in protein and high in simple carbohydrates, progress tends to slow.
3. You are eating too many soft foods
Some people struggle to return to solid foods after surgery. They may feel that chicken or other protein-rich foods do not go down well. Over time, this can lead to avoiding solid proteins and relying on foods that slide down easily, such as yoghurt, mashed potato, creamy soups or even ice cream.
The problem is that these foods lack structure, contain fewer nutrients and often bring hunger back quickly. They also tend to be high in simple carbohydrates, which slows progress. Looking closely at your eating habits often reveals whether soft foods are taking up too much of your diet.
4. You are exercising too much, too soon
It is natural to feel motivated after surgery and want to speed up weight loss with intense exercise. But doing too much too early, especially while eating very little, can slow weight loss instead of speeding it up.
Walking is excellent and recommended from the start. Anything more strenuous should wait until your surgical wounds have healed, usually 6 to 8 weeks after surgery. You should also be comfortably meeting your dietitian’s calorie target before you begin structured workouts.
5. You are not exercising at all
Nutrition plays the biggest role in your results, but exercise still matters. Building lean muscle increases your metabolism, helping your body burn calories more efficiently.
Once you are past the 6 to 8 week mark and your diet is balanced, adding regular activity can noticeably support fat loss. A good guideline is the NHS recommendation of at least 150 minutes of moderate activity a week. If you are unsure where to begin, ask your bariatric team or a trainer for guidance, and remember that many workouts can be done at home.
Be patient, your body needs time
Weight gain did not happen overnight, and weight loss will not disappear instantly either. Temporary stalls are a normal part of the process, and they do not mean the surgery has failed or that you have done something wrong. Weighing yourself too often can make progress seem slower than it really is, so give your body time, usually a few weeks, to adjust and continue burning fat.
Everyone is different. General advice can guide you, but your own needs determine how fast you lose weight, so try not to compare yourself with others. If you are consistently following the guidance but still not losing weight, speak to your dietitian, who can help you find what needs to change.
