iPhone app

Some apps have barcode scanners to provide nutritional information on products at the grocery store. (Adam Hunger/Reuters)

Weight-loss mobile apps lack most of the behavioural strategies people need to stay motivated and on track, a new study suggests.

In Tuesday's online issue of the American Journal of Preventive Medicine, researchers looked at 30 weight-loss apps for iPhone and Android platforms to see if they included any of the 20 behavioural strategies that previous studies showed were effective for weight-loss and reducing risk for cardiovascular disease and Type 2 diabetes.

On average, the apps included about 19 per cent of the 20 strategies, the researchers found.

Weight-loss goal setting, dietary goal setting and calorie balance were the most common.

Some strategies were completely missing, such as:

  • Stress reduction.
  • Relapse prevention.
  • Developing a regular pattern of eating.
  • Instructions on how to read nutrition labels.

"Weight-loss mobile apps have proliferated in the marketplace but appear to reflect a narrow range of behavioural strategies," study author Sherry Pagoto, a professor of medicine and behavioural psychologist at the University of Massachusetts medical school in Worcester, Mass., and her co-authors concluded.

Technology-enhanced features on the apps were most commonly barcode scanners to instantly get nutritional information on products in the supermarket (57 per cent) and a social network for users to encourage and support each other.

Email and text reminders and calendars for scheduling exercise and tracking food intake were also options on some apps.

Paid mobile apps, which ranged in price from 99 cents to $4.99 US, were no more likely than free apps to include behavioural strategies, the researchers said.

The MyNetDiary, which is free, included the highest proportion of evidence-based strategies.

"Where we're hoping the next generation of apps can do better is in incorporating some of those strategies that help the user who might not be so good about entering their diet every day and staying on track with their goals," Pagoto said in a release.

Some of the apps had other features at extra costs that were not evaluated, such as contact with a coach, companion websites and DVDs.

The list of apps was limited to those in the top 100 in the health and fitness category of iTunes and the Android Market.