I don't think this is true. Doctors do tell patients if they are overweight, and they do encourage them to make lifestyle changes including losing weight.
"Fewer than one of five overweight patients and slightly over half of obese patients reported being told they were overweight by their provider."
So "rare" is the wrong word.
https://www.commonwealthfund.org/publications/journal-articl...
I don't think this is true. Doctors do tell patients if they are overweight, and they do encourage them to make lifestyle changes including losing weight.