Thin friends who eat a lot could put your waistline at risk, according to a new study in the Journal of Consumer Research, which examines how other peoples’ weight and food choices influence how much we eat. “Obesity is obviously a tremendous public health concern,” write authors Brent McFerran, Darren W. Dahl (both University of British Columbia), Gavan J. Fitzsimons (Duke University), and Andrea C. Morales (Arizona State University).