keep off most of the weight they initially lost, said lead researcher Bonnie Spring, from the Northwestern University Feinberg School of Medicine in Chicago. The benefits of using an app on a mobile device, Rao said, are that it can be cheaper and widely available, and can help re-engage people who are having trouble, unlike an in-person program with a specific end date.
Although PDAs have mostly fallen out of fashion, the researchers said smart phones can serve the same purpose as the devices used in the study. Spring said most weight-loss apps on the market haven't been scientifically tested but may still help people lose weight.
Still, Rao warned, there's evidence that apps alone don't have much of an impact - and it may be more helpful to think of the technology as an aid to help from a doctor or nutritionist.