How crowdsourcing can keep your weight down

Avid users of smartphone apps may find it a lot easier to stick to a healthy diet through crowdsourcing, keeping their weight in check in the process, says a study.

"Crowdsourcing has the potential to improve adherence to dietary self-monitoring over a longer period of time," researchers said, adding that peers can rate both healthy and unhealthy foods in the expected direction.

"The results of this study found that when basic feedback on diet quality by peer raters is crowdsourced, it is comparable to feedback from expert raters," they added.

The researchers used 450 photographs of food/drinks uploaded onto the app called "Eatery" by 333 unique users in Europe and the US.

This app enables users to rate their meals on a basic sliding "healthiness" scale from "fit" (healthy) to "fat" (unhealthy), and to rate the photographs of other app users in the same way, in a bid to help them improve the quality of their diet.

Three public health students were asked to rate the same pictures, using a more complex scale, based on a set of nutritional standards - the 2010 US Dietary Guidelines - with points deducted for unhealthy components and added for healthy ones.

The expert raters' scores were then compared with those of the app users.

The results showed that both sets of ratings were similar, added to which the app users' scores were in line with the national guidance.

The study appeared in the Journal of the American Medical Informatics Association.