Red flags for pound-shedding profit-seekers.

• Position: Weight Control

With multiple highly credible studies underscoring the effectiveness of employing financial incentives to motivate weight loss, including those cited in the Archives of Internal Medicine and the Journal of the American Medical Association, the marketplace has followed suit with various companies now offering the opportunity to "diet for dollars," but how can health-seekers discern if a website offering to pay for lost pounds is legitimate?

David Roddenberry, cofounder of HealthyWage, New York, provides a list of red flags that can indicate a weight loss company offering monetary rewards may not be on the up and up:

Lack of weight verifications. If you are winning money or other prizes for losing weight, expect your weight loss to be verified by a third party. If there is no such verification or audit process from a credible third party, rest assured there are problems with this program.

You are required to purchase a third-party product. If the company requires you to purchase food, pills, clothing, or other products in order to earn your money for losing weight, it would be wise to step back.

Inaccessible service or support. If you cannot reach someone quickly via telephone or e-mail to answer questions about the program, you should be cautious and...