Tuesday, March 12, 2013

What Reading that Give Dieters Money to Lose Weight Article Actually Told Me

Wow did this paper get more press than it deserved, and it's not even a paper!

For background, if you haven't heard people are tweeting and posting links to a story that suggests, "Cash Can Coax Dieters to Lose Weight" while that same story has made headlines the world over.

Not one to post links to abstracts or press releases without reading the paper, but intrigued by the attention, I set out to find the paper and read the study.

So what'd I learn from the read?

Firstly that there's actually nothing to read. There is no published study. Here we're talking about an abstract that was presented 3 days ago at a cardiology conference.

Secondly I learned that regardless of the fact that the folks who were paid cash did better, "better" meant losing 9.1lbs in a year vs. 2.3lbs, and a dropout rate of 38% vs. 74%. Now the dropout rate in the cash group is pretty typical for a behavioural weight loss intervention, perhaps ever so slightly better than average even, but certainly nothing to write home about if the suggestion is that cash helps with adherence. And what's there to be made from the staggering 74% dropout rate in the control group that received the same freely provided intervention? My take is that the intervention they used must be truly awful as how bad does your freely provided weight loss intervention have to be to yield a drop out rate of 74%?

And what of the losses? 9.1lbs? Considering the press release reports the participants' average BMIs ranged between 30 and 40, the 9.1lb intention to treat loss to me sounds like pretty much what you would expect in a well designed behavioural weight management program without cash incentives, while the 2.3lb loss is lower than would be expected of a well designed program.

Lastly I learned that the abstract's presenter/author disclosed a financial relationship with a company called GymPact which as you might guess, uses financial incentives and disincentives in encouraging people to exercise.

The one thing I didn't learn is anything about long-term outcomes. I'd argue that especially with an intervention like monetary incentivization we need the long-term data as I'd bet that for many the money involved might lead them to "try harder" which while you might think that'd be a good thing, my experience has taught me the opposite. Whereby if the money led a person to be all the more strict with their lifestyle changes they'd be far less likely to sustain that degree of strictness when the incentive to do so disappeared.

I can't fathom why this abstract made headlines. The weight loss was minimal. The drop out rate abysmal. The study too short. And it's just an abstract! One thing however is certain - the fact that this abstract with really lame outcomes captured the world's attention is a truly terrifying statement as to what passes for news these days when it comes to obesity.

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  1. I am currently doing a PhD looking at motivation and Health Behaviour and the theory I am using for my theoretical frame work because states what you would predict-that once the incentive is removed people don’t try as hard anymore but it also states providing individuals with monetary incentive actually negatively impacts their efforts during the intervention. so basically they would do the bare minimum to make sure they got their reward each time but they wouldn’t go above and beyond, which may explain why the participants did not actually lose any more weight than what you would find in another intervention. So my intepretation is basically money doesnt do much to aid weight loss but just means you will have lots of people join your programme at the beginning and not drop out.

  2. What motivates those Biggest Loser contestants? Last I checked, the U.S. prize was $250,000 (USD). Or are they motivated by "15 minutes of fame"?


  3. There are lots of different "periods" of motivation: getting people to sign up, getting people to stick with it, getting people to lose a certain amount of weight, etc. But ultimately, will that motivation continue once the "reward" is removed? I doubt it.

    Some people are motivated simply by "winning." Some people are very goal oriented and like to have a carrot dangled in front of them.

    But none of those things, as you so often say, Yoni, will result in long-term maintenance of the weight loss, unless you can live with whatever you had to do to achieve it in the first place.

    1. Actually, now that I think about it, I am somewhat being motivated by money to lose weight right now: I've beein with WeightWatchers for the last two years. I am 2.2 pounds from my goal weight. Once I reach it and maintain it for 6 weeks I will become a "Lifetime" member, meaning I won't have to pay for meetings anymore. Then, as long as I don't go more than 2 pounds above my goal weight, I won't have to pay for another meeting. Is that motivating me? Definitely! Will it keep motivating me once I reach "Lifetime"? Maybe. But I'm very committed to my healthy lifestyle now and can't see myself going back to my unhealthy ways.

  4. Anonymous11:15 am

    I was part of a study a few years ago - a cancer prevention study in AB. They gave us financial incentives to join an accepted weight loss program (Weight Watchers was one of the few) and there were payouts at certain points long the way, including up to 2 years out. It was very effective for me, and basically paid the cost of the WW membership. Once study stopped I quit WW and it has ever so slowly come back ... not all the way, but 2/3 of it almost 4 years later. I would not have joined WW without the financial incentive.

  5. As significant as doing a "study" on the long-term efficacy of joining WeightLossWars.com.

  6. I think for the majority of the participants it was just a short term fix with weight loss being maintained - but only while the financial rewards were in place.

  7. Bobbini8:48 am

    I can tell you why the study got press: it puts the blame on the fat people. The message in the coverage is "anybody can lose weight if they want it badly enough--see, you just have to throw some money at the greedy swine!"

  8. Anonymous2:11 pm

    I saw the story and reminded me of my senior year in high school. My parents paid me to lose weight so that "I would look nice in my prom dress". I lost the weight, collected the cash, and promptly gained the weight back plus some. I still have memories (the year was '88) of heading to Wendy's right after they paid me the money... Regardless, I weigh less now than I did then, and it hasn't been due to any financial incentive. Paying people to lose weight is only a short term incentive.