Wednesday, October 24, 2012

A Penny For Your Thoughts, and $100 For Your Fat!

It's been some time since my last post. Turns out trying to start something new is not easy, as anyone who has tried to make or break a habit knows. This is something that many people that struggle with weight loss already know. But what can make changing your lifestyle easier? In the U.S.A. we have greatly diminished smoking through legislation that makes it inconvenient and expensive to smoke. This idea is now being actively applied to creating a more healthful food environment that promotes weight loss. Probably the most publicized "bad boy" of the food world is sugar sweetened beverages. Vending machines are being removed from public schools, limits are being placed on the size of sugar sweetened beverages you can purchase, and proposals for taxes on sodas have been made (but usually are not actually passed). So is all of this political interference doing anything? Science Says...Maybe, maybe not (of course science gives such a flimsy answer). The research as to whether there is a difference on our waist size or diabetes rates after attacking sugar sweetened beverages is thus far inconclusive for many reasons, most notable is the fact that this is all so new and it takes some time to see large changes.

So, let's address this issue from the other side. Instead of punishing people for wanting to drink a root beer each and everyday, could we instead give them money if they don't? You may have heard about schools in Ohio and Washington D.C., among others, that are paying their students to attend class and behave. While this has been met with plenty of controversy, it is an interesting idea that may expand to weight loss. In 2008 a study was published in the Journal of the American Medical Association that demonstrated the effect paying people to lose weight has on their ability to do so. Participants in this study were overweight (BMI was between 30 and 40) but overall healthy. There were randomized into one of three groups: the control group was given a weight loss goal and a scale. The deposit contract group was allowed to contribute $0.01 to $3.00 a day, and that amount was matched by the researchers. At the end of a month, if this group reached their weight loss goal they were refunded with their own money plus the matched deposit from the researchers. However, if they did not make their weight loss goal for the month they did not get any money back, so this group was mimicking what would essentially happen if we both rewarded people for weight loss but also punished them for lack of weight loss. The final group, called the Lottery group, got to choose a a two digit number. If this number was selected at the end of each month and that participant had met their weight loss goal they got either a $10 or a $100 monetary reward. Therefore, the Lottery group represents what would happen if we simply rewarded weight loss without the punishment. So what happened?

After 4 months of the study both of the incentivised groups loss an equal amount of weight (yay!), but the amount did not differ between the Deposit contract and the Lottery group. That means, in this study at least, it doesn't matter whether you reward and punish, or just reward people for losing weight. The study ended after 4 months, but after 7 months the researchers returned to the participants to see if their was weight regain. You can see above that even after 7 months those that were in either the Deposit contract or the Lottery group still had lost weight relative to their initial weight, but these differences in weight loss weren't significant when comparing them to the control group.

These same researchers published another article about the same participants, this time looking only at the comparison between the control group and the Deposit contract group. This study lasted 8 months, and you can see below that the Deposit contract group decreased their weight relative to their baseline measurement. Again, at 17 months post-study initiation when the participants were on their own there was no difference in weight loss between the two groups.

So what do you think? Is it worth paying people to lose weight? And how would this cost compare to the financial burden obesity and its related illnesses already put on us? Most importantly, would something like this ever get passed at the federal level in my life time without an anti-socialist revolt? Is Scienticklish getting political???

Volpp, KG, et al. Financial Incentive-Based Approaches for Weight Loss: A Randomized, Controlled Trial. JAMA (2008)

John, LK et al. Financial Incentives for Extended Weight Loss: A Randomized, Controlled Trial. Journal of General Internal Medicine (2011)

This is a great review of studies through 2010 that have looked at incentivising weight loss:
Robert Jaffery. Financial incentive and weight control. Preventative Medicine (2012)