Prognosis: A Modern Spin on Dieting

Weight loss companies promote healthy habits instead of prescriptive eating, but it's hard to overcome the yo-yo effect

- Rebecca Penty, David Rocks, and Rick Schine

Dieting has never been fun, but it used to be more popular. About a quarter of US adults report being on a diet, compared with 31% in 1991, says market researcher NPD Group. Sales of diet books, once reliable bestsellers, have fallen by almost half since 2004, according to data from NPD BookScan. People are moving away from restrictive eating because of a growing recognition of its limited effectiveness in keeping weight off, as well as greater advocacy for accepting all bodies and more awareness about mental health considerations. And the $192 billion-a-year weight loss industry is responding to the shift.

Companies say they can help people slim down through a holistic lifestyle approach, with healthy habits like exercise, getting adequate sleep, and eating plenty of fruits and vegetables. Noom Inc. says users of its app can stop yo-yo dieting and "get healthy again." Rival app Wellory says its clients can "dump dieting for good." Weight loss chain Simply for Life promises results without gimmicks or quick fixes.

Modern programs dangle a better relationship with food, more energy, and new exercise habits. But dietary changes, calorie counting, and regular weigh-ins can still play a major role. It's also not clear the approaches are any better than old-school dieting for long-term weight management. Noom often cites a study that found 78% of users sustained weight loss over nine months, though the study also found that only about 24% kept weight off for longer periods, as a psychologist's analysis of the data pointed out.