The National Institutes of Health is spending nearly $700,000 for a study that will pay obese teenagers to not eat as much.

A University of Minnesota study that began earlier this year is analyzing whether teens who receive financial incentives for replacing meals with liquid shakes is an effective anti-obesity tool.

"Severe obesity is the fastest growing category of pediatric obesity, with a reported prevalence near 6 [percent] in the United States," according to the grant for the project. "Unfortunately, conventional treatment approaches rarely result in sufficient weight loss in adolescents with severe obesity; therefore, innovative and effective strategies are desperately needed."

"The financial incentive model has been used successfully in adult obesity trials to address suboptimal adherence to lifestyle modification therapy and improves weight loss outcomes," the grant continues. "Although yet to be investigated as a weight loss intervention among adolescents, financial incentives have been shown to improve many health-related behaviors in teenagers."

The study will involve a yearlong trial with 142 obese teens. A grant worth $686,350 was awarded in April, and research will continue through March 2022.

Researchers believe paying obese teenagers will be a more effective weight loss method if it is paired with "meal replacement therapy," or substituting liquid shakes such as Slim Fast for regular meals.

"This research targets a significant public health problem, will utilize an innovative treatment concept and approach, and will generate new knowledge to guide selection of treatment type and intensification, ultimately exerting a powerful and sustained influence on the field of pediatric obesity," the grant states.

A 2012 Canadian study details several obesity payment programs used by other countries. The paper cites the United Kingdom's "nudge unit," which started a program called "Pounds for Pounds."

The program rewarded obese Brits with up to £425, roughly $577, if they maintained weight loss for 6 to 12 months.

"Six hundred obese participants, with an average starting weight of 218 pounds, lost an average of 14 pounds in six months and 29 pounds over 12 months," according to the paper. The payments amounted to between $19 and $41 for every pound lost.

The 2012 study concluded that short-term payment incentive programs are not as effective as those that continue to pay people for losing weight for a long period of time.

The NIH has funded several similar studies involving paying patients to be healthier. One study that has cost taxpayers $3,639,417 since 2013 is paying low-income pregnant women not to smoke.

Another UCLA study, which has cost $1,432,544, is giving financial incentives for obese adults to shed pounds.

A third study, costing $1,560,895, is analyzing the difference between paying obese adults directly for losing weight versus randomly selecting a lottery winner for individuals enrolled in its weight-loss program.

Aaron Kelly, an associate professor at the University of Minnesota who is leading the project, declined to comment on the specific details of the payment because the study is using a "deception design."

"This means that participants randomized to the control group will not know they are in a trial of financial incentives until after they are done," he said. "This is [Institutional Review Board] IRB approved but we don't want to highlight the true nature of the study too much for risk of contaminating the design."

Update 11:15 a.m.: This post has been updated with comment from Aaron Kelly.