The findings came from a study of nearly 8,000 men and women from 1995 to 2002 as they matured from teenagers to young adults, reported the online edition of health magazine WebMD.
The participants reported their height, weight, physical activity, screen time (time spent watching TV, using a computer, or playing video games), and relationship status in the mid-1990s and in 2001-2002.
In the mid-1990s, none of the participants was married or living with a partner. By 2001-2002, 16 percent were living with a partner and 14 percent were married.
The researchers from the University of North Carolina found that women who had married or moved in with a partner by 2001-2002 were more obese than women who were still single.