Trying to be healthier can help your partner lose weight too, study finds

It's called the 'ripple effect'

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When you’re trying to lose fat, friends and family often fall into two camps: the supporters and the saboteurs.

And while you may work in an office full of feeders, proffering cake and biscuits at you wherever you turn, this probably isn’t the case at home.

A new study has found that when someone is trying to lose fat, slim down or generally get in shape, there’s a higher chance their partner will too.

“The concept is called the ripple effect and it means that weight loss interventions delivered to one spouse have unintended, but positive benefits on the other spouse,” said study co-author Amy Gorin, Associate Professor in Psychological Sciences at the University of Connecticut.

“That is, spouses that are not actively involved in (a diet) treatment also tend to lose weight.”

In research published in the journal Obesity, Gorin and colleagues note that when your partner is trying to eat more healthily and exercise more, this is likely to boost your own motivation to do so.

However the trend goes both ways - if one person starts gaining weight, it’s likely their partner will too. In fact, recent research shows that being in a relationship is linked to weight gain.

Gorin’s team of researchers studied 128 cohabiting hetero and homosexual couples over a six-month period, most of whom were married and all of whom were overweight or obese.

The couples were split into two groups - for half of them, the person most interested in weight loss was put on Weight Watchers. For the other half, again, the person most keen to lose weight was given a basic handout containing information on healthy eating, staying active and weight management strategies.

The partners less interested in slimming down received nothing.

Three months into the study, the people doing Weight Watchers had lost more weight than those trying to slim down by themselves. However after six months, this difference had disappeared.

But most interesting, however, was what happened to the partners of those trying to lose weight.

After three months, the non-dieting partners had lost an average of 1.3kg (nearly 3lb) and three months later, that had risen to 2.02kg (about 4.5lb).

By the end of the six months, 32 per cent of the ‘non-treated’ partners had lost at least three per cent of their initial body weight, study coauthor and Chief Scientific Officer at Weight Watchers International Gary Foster told Reuters.

“What is most interesting to me about the study is that... they found the interventions were equally effective,” said Megan Lewis, Director of Patient and Family Engagement Research Program Center for Communication Science RTI International.

“The fact that the study found a minimally intensive, self-guided intervention was as effective as the Weight Watchers intervention suggests that the benefits of weight loss can spread within couples, and (individuals) may not need expensive or structured programs for this benefit to occur.”

The study, which was funded by Weight Watchers International, concluded that there was a high correlation between the weight loss of the ‘treated’ and non-treated partners. So the more weight lost by the person consciously trying to be healthier, the more their partner was likely to lose.

Gorin acknowledges, however, that more research needs to be done into this ripple effect: “We need more research to understand how to harness the power of behaviour change within households.

“Spouses clearly influence each others’ weight-related choices. But how can we leverage this within interventions to produce greater and more sustained changes?”