I kind of think if it fixes a fundamental issue - too much weight.

Another problem it seems to help with is addictive/impulsive behavior. This might lead to wrong choices in diet or activity.

I suspect that many many functions of the body are degraded or disabled by too much weight or wrong choices, and fixing those problems might let the body cure and maintain itself properly.

Obesity may increase the risk of Alzheimer's but it's far from a requirement for the disease. I can't find a link between Alzheimer's and being overweight except in case of obesity.

https://www.alzheimers.org.uk/about-dementia/managing-the-ri...