Old Couple

Evidence for a Spousal Benefit in Weight Management

Obesity seems to move through a person’s social network, as we described here last week. But today, we have a new study in Obesity that shows the positive effect that a very intimate social network can have. In a randomized controlled trial, researchers found good evidence for a spousal benefit in weight management. When one spouse is losing weight, the other spouse loses, too.

Benefit Independent of Treatment

The study randomized one member of a couple to either Weight Watchers or a self-guided weight loss program. Untreated spouses were mostly male (68%), white (96%), and heterosexual (97%). For the treated spouses, Weight Watchers worked better in the first three months. Then by six months, that difference faded, so that the difference between the two groups was no longer significant. The self-guided group lost about four percent of their starting weight, while the Weight Watchers group lost five.

For the untreated spouses, it made no difference which treatment their partners received. About a third of them lost three percent or more of their starting body weight – the threshold for significant benefits.

What did matter was the weight their partners were losing. The more weight their partners lost, the more weight those untreated spouses lost. And the correlation was highly significant (p<0.001).

While it’s clear that outcomes are linked within couples, it’s not clear why. Is the spouse who’s getting treated having an effect on the other spouse? Is it the other way around? Or perhaps, the encouragement goes in both directions.

Consistent with Earlier Studies

We’ve seen this effect within couples before. It seems that spouses of people getting effective obesity treatment will lose about two to three percent of their body weight. It happens with intensive lifestyle therapy and it happens with bariatric surgery.  Though this study has some limitations – it’s not very diverse – it adds solid evidence for the interdependence of couples regarding weight management.

Weight is a very personal issue. This study shows how helpful a supportive spouse can be when dealing with it.

Click here for the study in Obesity, here for similar data from the Look AHEAD study, and here for data from partners of gastric bypass patients.

Old Couple, photograph © Hartwig HKD / flickr

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February 1, 2018