> I have family members with no excess body weight - bmi in the single digits
You must be from a family of bots, highly intelligent snakes, or something like that. If you’re 2 meters tall, a BMI of 10 means a weight of 40kg. If you’re 1 meter tall, it means a weight of 10kg.
I’m not even sure humans with a BMI of under 10 can survive.
For most Americans the main cause of high blood pressure is excess uric acid, itself a product of excess sugar intake. Advanced imitation food substitute producers pack sugar into practically everything nowadays. It is hard to avoid it when buying anything processed.
There are like 50 variables. Weight is a big one, but not the only one.