New York, Oct 21 (IANS): With fitness apps, the press of a button on smartphone can help you record daily calorie consumption and exercise but they alone cannot motivate you enough to lose and maintain weight loss in the long term, say researchers.

In a 24-week behavioural study that combined traditional weight control intervention with smartphone-assisted helps, researchers found that teenagers lost weight initially, but could not maintain it when smartphones were the only tool helping them stay on track.

Combining fitness apps with social support and accountability are the key, the study said.

"We know that teenagers are on their phones, which gives us a way to intervene in the moment," said lead author Chad Jensen, Professor at Brigham Young University in Provo, Utah, US.

"We wanted to determine whether we could effectively use texting and a commercially-available smartphone app to help adolescents with weight loss," Jensen noted.

The study, published in the Journal of Medical Research took place during two consecutive 12-week periods, the first of which combined electronic (smartphone) intervention and traditional in-person treatment.

During this period, each of the 16 participants met weekly with a clinician and other participants to share their experiences and discuss topics like adopting healthy eating patterns, reading food labels and increasing physical activity throughout the day.

In addition to these meetings, the teenagers were encouraged to record their daily food intake and exercise on the Daily Burn app.

They also received text messages from the researchers three times each day to encourage healthy behaviour and pose thought-provoking questions about motivations.

Study participants achieved modest weight loss during this period, decreasing their body mass index (BMI) by 0.08 points on average.

But the in-person meetings were removed for the second 12 weeks of the study, so the only interventions helping the teenagers stay motivated were the daily texts and self-monitoring on the Daily Burn app.

During this period, self-monitoring rates dropped from nearly 50 percent to 16.8 percent and the participants regained their lost weight.

A possible reason for this result is that smartphones, no matter how helpful or easy-to-use, lack certain critical characteristics present during the in-person treatment, Jensen suggested.

These results emphasise the importance of social support in creating lasting change and motivating healthy behaviour.

But this does not mean that smartphone fitness tools are useless -- they are just best used as an add-on to augment other fitness habits by making it easier to track behaviour and progress.