A “health sinner” is a person who does not conform to the current norms for proper health, such as someone who eats the wrong foods or who doesn’t get enough exercise. “Health sinner” has been cited in print since at least 1922, but became popular in the 2000s. A January 2013 Associated Press story about public healthcare was titled “Why Not Just Let These Health Sinners Die?”
 
The opposite of a “health sinner” is a “health saint,” but that term has been less frequently used.
   
 
Google Books
January 1922, The American Dentist, pg. 21, col. 1:
Hell fire seems necessary, to stir the latent interest of the average health sinner to early action in health insurance, especially in oral prophylaxis.
 
Google Books
July 1922, Oral Hygiene, pg. 1003:
This plan of dentistry’s disguises the virtuous mendicant (prophylaxis- applied biology) so that it does not ape religion, but which makes it quite palatable for the indifferent health sinner.
 
Google News Archive
11 May 1993, Lewiston (ID) Morning Tribune, “Why tax a cigarette and not a sausage as well?,” pg. 10A, col. 4:
Shouldn’t all health sinners be included, not merely because the tax load should be broadly shared, but as a favor to the fat and sugar consumers themselves?
 
Google Books
Scientific Authority and Twentieth-Century America
By Ronald G. Walters
Baltimore, MD: Johns Hopkins University Press
1997
Pg. 79:
By the 1930s, “health sinners” had become “health criminals,” and one could act as accomplice to the criminal germ against one’s own body.
 
Google Books
The Bragg Healthy Lifestyle:
Vital Living to 120
By Paul Chappuis Bragg and Patricia C Bragg
Santa Barbara, CA: Health Science
2004
Pg. 32:
Most men today are health sinners! Left to their own resources they will try to live on a bacon, sausage and eggs, strong coffee, white flour pizza, beer, biscuits, and gravy diet.
   
Google Books
Drop Dead Healthy:
One Man’s Humble Quest for Bodily Perfection
By A. J. Jacobs
New York, NY: Simon & Schuster
2012
Pg. 32:
Health saints and health sinners might have equal life spans.
 
Fox Nation
January 28, 2013,
AP: ‘Why Not Just Let These Health Sinners Die?’
NEW YORK (AP)—Faced with the high cost of caring for smokers and overeaters, experts say society must grapple with a blunt question: Instead of trying to penalize them and change their ways, why not just let these health sinners die prematurely from their unhealthy habits?
 
Annual health care costs are roughly $96 billion for smokers and $147 billion for the obese, the government says. These costs accompany sometimes heroic attempts to prolong lives, including surgery, chemotherapy and other measures.