https://news.harvard.edu/gazette/story/2007/07/obesity-is-contagious/ Skip to content The Harvard Gazette Search for: [ ] [Search] * Arts & Humanities * Business & Economy * Campus & Community * The Coronavirus Update * Events * Health & Medicine * Honoring the Class of 2021 * National & World Affairs * News & Announcements * Photography * The Quest for Racial Justice * Science & Technology * The Solutions Series * News + * About * Accessibility * Athletics News and Scores * For Media & Journalists * Privacy Policy * Trademark The Daily Gazette Sign up for daily emails to get the latest Harvard news. [ ] [Subscribe] Harvard University * * * * National & World Affairs Leon Starr. World 'I lost good friends' 80 years after Pearl Harbor, Leon Starr, Class of '40, recalls WWII service Caroline Light. World Difference between Rittenhouse and McMichael-Bryan verdicts? Caroline Light says it involves success in making perpetrator seem like victim Health & Medicine Vaccine bottles and a clock. Health Time of day matters when getting vaccine Antibody levels higher when people receive SARS-CoV-2 vaccine in the afternoon, say researchers [GettyImages-1253549805-1200x800] Health 'This virus is a shape-shifter' New study sheds light on COVID mutations, immune escape Featured * National & World Affairs + Health & Medicine * Arts & Humanities * Science & Technology * Business & Economy * Campus & Community + Experience + Commencement 2019 (c) 2021 The President and Fellows of Harvard College The Harvard Gazette Obesity is contagious Teen diets can hurt their lungs Health & Medicine Obesity is contagious Study shows spread through social networks By David Cameron DateJuly 26, 2007August 10, 2016 Share * Email * Facebook * Twitter * LinkedIn Trending 1. Moderna edges out Pfizer vaccine in head-to-head comparison [iStock-vaccine-card-] 2. Omicron 'astonishing to behold,' says Hanage [Hanage2500-150x150] 3. Keeping an eye on Omicron [AP_Airport] 4. How Omicron variant could affect University protocols [101321_features_RL_m] 5. Vaccine reduces transmission in breakthrough cases [012318_Flu_002-150x1] Public health officials have been working hard to account for the dramatic rise in U.S. obesity rates. Many obvious factors, such as poor diet and a sedentary lifestyle, certainly contribute to the swelling statistics. However, these and other explanations tend to focus exclusively on how individuals' choices and behaviors affect their own weight. Now, researchers from Harvard Medical School and the University of California, San Diego have found that obesity is hardly a private matter. Reporting in the July 26 edition of the New England Journal of Medicine, the researchers found that obesity spreads through social ties. When an individual gains weight, it dramatically increases the chances that their friends, siblings, and spouses will likewise gain weight. The closer two people are in a social network, the stronger the effect. Interestingly, geographical distance between persons in a social network appears to have no effect. "What we see here is that one person's obesity can influence numerous others to whom he or she is connected both directly and indirectly," says Nicholas Christakis, MD, PhD, a professor in Harvard Medical School's Department of Health Care Policy. "In other words, it's not that obese or non-obese people simply find other similar people to hang out with. Rather, there is a direct, causal relationship." Over the last 25 years, the incidence of obesity among U.S. adults has more than doubled, shooting from 15 to 32 percent. In addition, roughly 66 percent of U.S. adults are considered overweight. Christakis and U.C. San Diego researcher James Fowler, PhD, decided to analyze data from the Framingham Heart Study (an ongoing cardiovascular study begun in 1948) to see if any social patterns might elucidate these alarming rates. Editor's Picks Sham Kakade and Bernardo Sabatino. Science New University-wide institute to integrate natural, artificial intelligence Initiative made possible by gift from Priscilla Chan and Mark Zuckerberg Leon Starr. World 'I lost good friends' 80 years after Pearl Harbor, Leon Starr, Class of '40, recalls WWII service Holiday shoppers. Business Will Omicron damage the economy? Eric Maskin sees possible challenges, reason for optimism, and is not overly concerned, for now Trending 1. Moderna edges out Pfizer vaccine in head-to-head comparison [iStock-vaccine-card-] 2. Omicron 'astonishing to behold,' says Hanage [Hanage2500-150x150] 3. Keeping an eye on Omicron [AP_Airport] 4. How Omicron variant could affect University protocols [101321_features_RL_m] 5. Vaccine reduces transmission in breakthrough cases [012318_Flu_002-150x1] Up Next Health & Medicine Teen diets can hurt their lungs * * * *