Recent NEJM article* – If current rates of obesity are left unchecked, the current generation of American children will be the first in two centuries to have a shorter life expectancy than their parents .
The life-shortening impact of obesity (currently estimated at 1/3 to ¾ year) could rise to 2 to 5 years , or more, as obese children spend more years at risk for comorbid conditions.
Olshansky SJ, et al. A Potential Decline in Life Expectancy in the United States in the 21 st Century . NEJM, 352(11):1138-1145, 2005
Further investigation is needed, but thought that one reason certain types (i.e., RYGB) of bariatric surgery are successful at reducing food intake and causing weight loss may be related to enhanced secretion of satiety signals (ghrelin or others).