There are some effects of GLP-1s which definitely cannot be explained by weight loss. For example, some patients report that they lost their compulsive habits -

There are some effects of GLP-1s which definitely cannot be explained by weight loss. For example, some patients report that they lost their compulsive habits - gambling, shopping etc. In some, the effect is so extreme that it flips into outright anhedonia, an inability to enjoy anything. GLP-1s are ultimately treatments that act on our neurohumoral regulation, and hormones tend to have a lot of functions all around the body. Claude would say that the expected "blast radius" of fiddling with hormones is much bigger than that of just losing weight.