Bariatric physician: A physician practicing bariatrics, the field of medicine concerned with weight loss. Also called a bariatrician. The terms are used interchangeably. The American Society of Bariatric Physicians states that: "These guidelines provide suggestions for the work-up and follow-up of the bariatric patient. They are not intended to replace, and indeed cannot replace, the bariatrician's judgment regarding a particular patient's treatment.": licensed Doctor of Medicine (MD) or Doctor of Osteopathy (DO) who specializes in medical weight management. Bariatric physicians may treat overweight and obese patients with diet, nutrition, exercise, behavioral therapy, appropriate medications, or any combination of these treatments.