It looks like the study had a multi-pronged approach, but in terms of the mechanism of action, the study was focused more on the brain than the rest of the body, and the authors posit that the areas where the semaglutides are acting are resulting in decreased appetite.

The semaglutides are analogues of GLP-1 (glucagon-like peptide 1) which is released from cells in the intestine, with receptors in the body including in the pancreas, stomach, kidney, lung, heart, skin, immune cells, and the hypothalamus. It is one of the hormones involved in regulating blood sugar and digestion, partially through its regulation of other hormones.

So to sum it up, I don't think they just make you eat less, it seems like there's a hormonal/nervous system/gastrointestinal overlap in mechanism of action.

From that paper “The mechanism of action of semaglutide in patients with obesity is similar to that of liraglutide — primarily energy intake reduction — but semaglutide has also been shown to improve control of eating and food cravings and reduce preference for fatty, energy-dense foods (6), suggesting that semaglutide may affect food intake via hedonic as well as homeostatic pathways.”

So it does not just make you eat less. You know when you eat so much fatty food at one point you’re like i cant anymore or crave something light. That signalling is mimicked my semaglutide.

Also your body reacts to hunger by shutting down, so you start burning less and you plateau. This does not happen if instead of hunger you feel full. Semaglutide slows the food passing through you so you feel full.

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