Pertaining to weight (from the same root as in barometer -- measuring the "weight" of air), the aim of bariatric surgery is to reduce weight, including "morbid" or "clinically severe" obesity, in patients.

a branch of medicine dealing with the causes, prevention, and treatment of obesity, both pharmacological and surgical

A branch of medicine that deals with control and treatment of obesity and allied diseases.

Bariatrics is the branch of medicine that deals with the causes, prevention, and treatment of obesity.The American Heritage Dictionary of the English Language, 4th edition, Houghton (2000): http://www.bartleby.com/61/84/B0078400.html "Bariatrics" Retrieved 14 Feb. 2006 The term bariatrics was created around 1965 , from the Greek root baro ("weight," as in barometer) and suffix -iatrics ("a branch of medicine," as in pediatrics). Besides the pharmacotherapy of obesity, it is concerned with obesity surgery.