glennmatthew
This is a fixed forumula, where BMI = weight (kg) / heigh squared (m2). You'd need to use a calculator to convert imperial measurements to metric, which could be built into the tool.

Source: Hill, A, Marchese, R, 2011. The essential guide to fitness: for the fitness instructor. 2nd ed. page 103: Pearson Australia.

The actual problem here is grading people into a health risk, as the categories change from country to country. I would hate to see DDG just spitting out US-centric results, so you'd need 3 inputs:

1. Height
2. Weight
3. Nationality

My opinion- BMI is inherently flawed and should only be relied upon by general populations as a guide. Other measurements, such as waist to hip ratio (Van Itallie, 1988), would be a better measurement as the research is 16 years ahead and a better indicator of health risk.
posted by glennmatthew 3 years and 10 months ago Link

rixx
I agree that BMI is not the best metric for grading weight, that's why I wanted to include a link to the Wikipedia.

As for the grading, it's less dependent on the nationality and more on the age and gender of a person, which is why I'd consider leaving it out for now. Just return the value with a link to a place where you can see where you stand in regards to your age and gender?
posted by rixx 3 years and 10 months ago Link
glennmatthew
Wikipedia is probably the safest landing page, since the content can be readily updated as needed.

How would you intuitively capture the inputs? Just a simple "bmi 180cm 90kg" or "bmi 6'1" 200lbs"?
posted by glennmatthew 3 years and 10 months ago Link
rixx
Both of these (plus weight in stone) are what I'd be looking for.
posted by rixx 3 years and 10 months ago Link