Rite Aid has teamed up with Lindora, a medical weight control program, and fitness expert Denise Austin to design a Web-based weight loss program, available free at www.riteaid.com.

In addition, the drugstore chain is sponsoring a sweepstakes, with a spa getaway and a day with Austin as the prize.

According to the Centers for Disease Control and Prevention, about two-thirds of U.S. adults are overweight or obese, and 17 percent of children and adolescents are now seriously overweight. Being overweight increases a person’s risk for more than 50 diseases and conditions including heart disease, diabetes and hypertension.

The “Rite Weight Plan,” developed with Lindora, can help participants lose as much as 10 percent of their body weight in just 10 weeks, according to Rite Aid. People who sign up will get an initial guide, daily support through educational e-mails, a daily action plan to keep track of meals and exercise, a “Rite Weight Tracker” chart, food recommendations and menus, personalized question-and-answer sessions with a Lindora expert, interactive Web seminars led by Lindora weight loss experts, audio messages from Lindora experts, and Lindora “lifestyle assessments” to help participants find out if they are at risk for certain health conditions and discover what lifestyle changes they can make to counter those risks.

Also part of the program is a free 16-page weight-management guide, which is available in all Rite Aid stores and on the Web. The guide gives examples of simple lifestyle changes patients can make to look and feel better, hints on how to eat healthy when dining out, facts about fat, a body mass index calculator, and ways to help children develop healthy eating and exercise habits. The guide also features fitness expert Denise Austin giving her top 10 tips for making health and fitness a part of everyday routines, including fitness strategies, nutrition, and the importance of incorporating an activity you like into your workout.