Ghrelin is a hormone largely produced by the fundus in the upper portion of the human stomach and when released, sends signals to our brain to consume food for satiety. In many obese people the secretion levels of the ghrelin hormone are off-balance and may be one reason why obese people feel like they need to consume more food that they actually need.
While research on ghrelin is still relatively new, we do know that reduction of grehlin in the gastro-intestinal tract may allow for more consistent long-term weight loss. While almost every bariatric procedure restricts the amount of food the patient can consume at any given sitting, the gastric sleeve procedure also reduces the amount of ghrelin that is secreted in the body. This is because the portion of the stomach that is cut away and removed also contains the fundus which produces the hormone.
Gastric sleeve patients, unlike for example gastric band patients, will not only eat less food but they will also feel more satisfied throughout the day. So, in summary because the gastric sleeve is just a long thin tube, patients can’t eat much and because of the decreased ghrelin, they don’t care. GREAT COMBO!!!
In addition to ghrelin, there are other hormones in play when a gastric sleeve is performed. These hormones aid in satiety (feeling of fullness), decease apetite and glucose control, just to mention a few effects. While we do not have sufficient evidence on how creation of a gastric sleeve affects overall weight loss, we do know that it is not only a restrictive operation, but also a metabolic one.