Obesity is stronger than smoking, at least when it comes to which factor plays a larger role in killing you sooner vs. later.

An 18 year old in 2005 who quits smoking would increase his life expectancy by 0.31 years. However, if that young adult had a BMI greater than 25 — even after quitting smoking — his life would be reduced by 0.71 years.

“Forecasting the Effects of Obesity and Smoking on U.S. Life Expectancy,” a study in the December 3 2009 issue of the New England Journal of Medicine, finds that for all the good efforts in smoking cessation among Americans, the growing waistline of the American citizen is outweighing the positive health impacts of quitting smoking.

Dr. Allison Rosen, one of the study’s authors, said, “some Americans may rather have cheesecake now than an extra few months of life years down the road.”

Health Populi’s Hot Points: To address obesity in the U.S. will involve a host of factors beyond the health system. A survey from HealthFocus conducted in late November found that consumers are very interested in moving toward healthier products for both themselves and the environment. Heart health, brain health, stress, fatigue, bone and muscle health are all areas American consumers are keen to bolster.

However, HealthFocus found that while shoppers are demanding changes to brands in terms of more healthful ingredients, companies and government policies have been slow to respond to consumer demands.

Thus, HealthFocus finds that since its first survey on these trends in 1996, there has been only marginal changes in Americans’ lifestyle choices. In ’96, 45% of Americans were careful about dietary intake; the percentage is the same 13 years later.

The NEJM study researchers cite a study from 2004 that found that even modest reductions in weight can result in profound health changes. The study by Orzano and Scott, “Diagnosis and treatment of obesity in adults: an applied evidence-based review,” says to look at obesity as a chronic disease “of multifactorial etiology.” The authors found that modest weight loss results in improvement in the prevention of hypertension, diabetes, and hyperlipidemia.

The model illustrated here has implications for how to optimally deal with the multifactorial nature of obesity. “When system resources are available,” Orzano and Scott write, “a chronic disease care model that uses a collaborative team approach might provide opportunities to provide more intensive treatment and consistent reinforcement and follow-up.”

When Orzano and Scott wrote this article, they couldn’t foresee the emergence of mobile health and flexible, user-friendly apps that can help people make sound choices 24×7. Mobile health will play a role in managing the chronic nature of obesity — but apps aren’t sufficient for this complex health challenge. Government, local communities, and consumer goods companies much join with health citizens to impact this largest health challenge of the early 21st century.