How might muscular endurance activity be different for and individual who is thin compared to an individual that is obese? (30 words or more)

Used primarily for thickening sauces and soups, a (paste/roux/stock) is made from a (1: 2/2: 1/1: 1) fat and flour.

If a person has a bad pain in their back, specifically lower back a bit above the hip, what should they do besides going to the doctor? what remedies could they use?

How could you find out if that advice is based in scientific evidence?