Until she was in her mid-30s, Xanthia Walker rarely went to the doctor, even when she needed care. She didn’t want to step on the scale.

When she did go in — to treat sciatic nerve pain or get antibiotics — somehow the conversation always turned to her weight.

“Even when I went in about migraines, the response was, ‘Well, if you lost weight that would probably go away,’" she recalled.

That changed when Ms. Walker, 40, who lives in Phoenix, found a new physician. Dr. Natasha Bhuyan rejects what she calls the “weight-centric” model of medicine.

Instead, she favors a “weight-inclusive” approach recognizing that people come in different shapes and sizes, and that the number on the scale does not necessarily predict health status.

“When a person comes in, the first thing we do is not check their weight,” said Dr. Bhuyan, who is the vice president of in-office care and national medical director at One Medical, a primary care practice owned by Amazon.