Andrew Almon Fletcher (8 March 1889, Kingston, Ontario – 30 November 1964, Toronto) was a Canadian physician and pioneering diabetologist, known as one of the five co-authors of the famous 1922 paper Pancreatic Extracts in the Treatment of Diabetes Mellitus.
At Toronto General Hospital, in the diabetes ward under the direction of Duncan Archibald Graham, the physicians A. Almon Fletcher and Walter R. Campbell[3] were responsible for the treatment of Leonard Thompson, a teenaged charity case with a severe case of type 1 diabetes, who had been transferred on 2 December 1921 from Toronto's Hospital for Sick Children.
[4] Dr. Campbell persuaded Leonard Thompson's father to consent to the experimental test on his son of the pancreatic extract supplied by Banting, Best, and Macleod.
Especially memorable were Petren from Oslo, Woodyatt from Chicago and Wilder from Mayo's—these men were largely instrumental in the development of the high-fat diets then in vogue—and Elliott Joslin and F. M. Allen, who were advocates of starvation and undernutrition.
During this time further physiological papers appeared, describing the associated effects of insulin in addition to its influence on carbohydrate and fat metabolism.