Fitness apps are step in wrong direction for health

When your phone pings to congratulate you on 10,000 steps, do you feel a glow of satisfaction? Do you maybe even reward yourself with a treat?

Well you shouldn’t. Because there is scant evidence that you have helped your health, and a possibility you might have even done the reverse.

Greg Hagar, a professor at Johns Hopkins University, said that while fitness and health apps have surged in popularity, in most cases there was no solid evidence base for their use. “There are tons of apps for healthcare. Roughly 165,000 was quoted last year,” Professor Hagar said at the annual meeting of the American Association for the Advancement of Science in Boston. “Very few are science-based.”

He pointed to recent research into mental health apps, which found that of the hundreds on the market none had any evidence to support their use.

Professor Hagar, a computer scientist who works in medical devices, said: “Some of you might wear Fitbits or something equivalent, and I bet every now and then it gives you that cool little message ‘you did 10,000 steps today’ — but why is 10,000 steps important? What’s big about 10,000? It turns out in 1960 in Japan they figured out that the average man, when he walked 10,000 steps a day, burned something like 3,000 calories and that is what they thought the average person should consume so they picked 10,000 steps as a number. But is that the right number? Who knows.”

Then there are the unintended consequences of that “ping”. A recent study by the University of Pittsburgh found that fitness trackers seemed to have a negative effect on people trying to lose weight, possibly because they rewarded themselves for hitting the goal.

Professor Hagar said that “single solution” apps were not always appropriate. “We all know that probably the more you exercise, the better it is for you. But if you are elderly or infirm then this is not going to be good for you. I think apps could definitely be doing more harm than good.”

Steve Flatt, director of the Psychological Therapies Unit in Liverpool, recently published a paper on the efficacy of fitness apps in the BMJ. He said: “Unfortunately the designing and testing stages seem to have been largely missed out in the race for profits.”

• Yo-yo dieting may not be bad for you after all, research has suggested. In experiments on obese mice, a quarter were returned to a normal weight, a quarter lost weight but stayed fatter than they should have been, a quarter were kept obese and a quarter were put on a fluctuating diet. David Allison, from the University of Alabama, said that those on the fluctuating diet were as healthy as those kept just overweight and a lot healthier than those who stayed obese. However, Tim Spector, from King’s College London, said: “Data in humans shows that yo-yo dieting makes you gain weight long-term.”