Ripple Effect in Couples
What’s good for one spouse or partner, may be good for the other, particularly when it comes to weight loss, according to a new randomized controlled study published in February in the peer-reviewed journal Obesity.
Researchers from the University of Connecticut describe a ripple effect between couples: when one makes an effort to lose weight, the chances are, the other will shed pounds too, even if he or she does not actively participate in a weight loss program. Couples were defined as two people cohabitating regardless of marital status.
In the study, 130 couples were randomized into two groups. In one group, the individual that was trying to lose weight enrolled in a structured six-month weight loss program (Weight Watchers) and in the second group, one of the couple only received a four-page handout with information on healthy eating, exercise, and weight control strategies. The study was funded by Weight Watchers International. The dieting member of the couple started out with a body mass index (BMI) of between 27 and 40. The other member of the couple had a BMI of at least 25.
After six months, about one-third of the partners who were not part of any deliberate weight loss effort, still lost 3 percent or more of their initial body weight. The study also found that if the dieting partner lost weight at a steady pace, or if he or she struggled, their partner also struggled.
"When one person changes their behavior, the people around them change," says study author Amy Gorin, associate professor in psychological services at the University of Connecticut. "Whether the patient works with their healthcare provider, joins a community-based, lifestyle approach like Weight Watchers, or tries to lose weight on their own, their new healthy behaviors can benefit others in their lives."
After six months, participants in the Weight Watchers program lost an average of 9.5 pounds while those who tried to lose weight on their own lost nearly 7 pounds. The non-dieting spouses – no matter which group their partner had been assigned to – lost an average of three pounds at month three, and four and a half pounds at month six.
When researchers compared their findings to the broader ripple effect reported in previous studies, the mean weight loss observed among non-dieting spouses was consistent with the 2 percent to 3 percent weight loss observed in untreated spouses of individuals undergoing bariatric surgery or participating in lifestyle-based programs at academic medical centers.
Researchers wrote, “Given these similarities in ripple effects across a wide variety of intervention methods, it may be that some form of treated participation by spouses is needed to achieve consistent weight losses greater than 2% to 3%.”
Previous studies have found that spouses often enter marriage at a similar weight status and mirror each other's weight trajectories over time. In a landmark study published in the
New England Journal of Medicine in 2007, researchers found a person’s chances of developing obesity increased by 57 percent if even a friend had developed obesity.
Family members of patients who have undergone surgery for weight loss may also shed several pounds themselves, as well as eat healthier and exercise more, according to a
2011 study by researchers at Stanford University School of Medicine.
A year after the 35 patients in the study had Roux-en-Y gastric bypass surgery, their adult family members with obesity participating in the study lost an average of eight pounds. In addition, researchers said many of the children in these families appeared to benefit through their close association with the patient -- they exhibited a lower BMI than would have been expected given their growth curve.
“Family members were able to lose weight comparable to being part of a medically controlled diet simply by accompanying the bariatric surgery patient to their pre- and post-operative visits,” said senior author John M. Morton, MD, MPH, past-president of the ASMBS and chief, Bariatric and Minimally Invasive Surgery, Stanford School of Medicine, in a news release at the time.