This paper provides a helpful breakdown of types of mortalities and how they're associated with BMI. It's interesting to see that the lowest All-cause mortality is at a BMI of 25. A BMI of 30 doesn't increase the hazard ratio that much, but a BMI of ~45 doubles it. The minimum for cancer mortality is notably lower (21) but perhaps surprisingly the minimum communicable disease mortality is at a BMI of 26.
https://www.thelancet.com/journals/landia/article/PIIS2213-8...
This kind of stat is misleading and is seen in many health metrics - blood pressure, cholesterol, etc. In fact, it's sometimes known as the "cholesterol paradox" because people with higher cholesterol have a lower risk of dying. However, it's misleading because blood pressure, weight, and cholesterol often come down as people suffer from chronic disease or malnutrition. The chronic diseases people get are often from their weight, blood pressure and cholesterol, and when this is corrected for, the all-cause mortality curves better reflect what a healthy person's numbers should be. So in reality the lowest point of the all-cause mortality curve for BMI is below 25. 25 is not optimal.
Dr. Carvalho recently made a video on this topic (he even mentions the BMI curve). You can watch it here: https://www.youtube.com/watch?v=n4h135SBebc
My cardiologist has been asking me to get on statins for a while but i've been not able to convince myself to get on board to take a pill for the rest of my life.
I've dug into this topic a lot sense there's a lot of heart disease in my family. I've found that eating a bowl of oatmeal once a day reduces my LDL under 130 (I've been taking quarterly cholesterol blood tests to keep an eye on things). It's probably the fiber content that's doing the work, but I haven't tried other high fiber foods yet. However, I'm not a doctor so make of this what you will.