| Why is this such a hard question? You would think a question as ubiquitous as "What should I eat?" would have more consensus. Some studies show extra mortality in normal to underweight people, including from common causes relevant to average people, but there's also a ton of work on calorie restriction? Is low BMI dangerous, or does it just commonly go along with a lifestyle that might lead to injuries and rhabdomyolysis and a case of diarrhoea in a place without hospitals? It would be interesting to see adventurousness treated as a separate category for controls. In the past there was no fridge, people stored their own energy, and there was no pepper spray and cops and forklifts, exercise programs had the extra constraint of physical activity being directly needed to survive. What amount and type of activity should a modern person who has reason to believe they'll probably never be in a serious fair fight with no weapons or need to walk 3 days to get help do? How much should someone eat when they do not ever plan to drink untreated water or go somewhere away from medical help if they catch some parasite that causes rapid weight loss? Is the ideal profile of nutrition changed for someone who will not be exposed to woodsmoke, bacterial illness, etc? And then furthermore, if higher BMI isn't helpful by itself, what should people who ARE in poverty or otherwise exposed to more stresses do? Is there a subgroup that needs a metabolic reserve? Should those people eat less to save money and be able to DoorDash if needed and have external reserves like people without poverty or adventurousness? Or is there a real independent benefit to some level of fat? |