Mobile app may improve eating behaviour – the changes are associated with weight loss
The results show that using the app increased cognitive restraint of eating and reduced uncontrolled eating, emotional eating and binge eating. Positive changes in eating behaviour were also associated with weight loss.
The FeelGood study included 200 people aged 18–65 with a body mass index (BMI) of 30–40 kg/m². Participants were randomly assigned to two groups. The first group was given access to the Onnikka mobile app at the start of the study, while the second group began using the app after a six-month waiting period.
The study examined four aspects of eating behaviour: cognitive restraint of eating, uncontrolled eating, emotional eating and binge eating. Eating behaviour and weight were assessed at baseline and at six, 12 and 18 months.
After six months, cognitive restraint of eating had increased among those using the app. At the same time, uncontrolled eating, emotional eating and binge eating had decreased. No corresponding changes were observed in the six-month waiting-list group before they began using the app.
When the second group began using the app, similar changes in eating behaviour were observed as in the first group. The positive changes were maintained in both groups through to the end of the follow-up period at 18 months.
The researchers also found an association between changes in eating behaviour and weight loss. The greater the increase in cognitive restraint of eating and the greater the reductions in uncontrolled eating and binge eating over the first six months, the greater the weight loss. In the first group, a reduction in emotional eating was also associated with weight loss.
The Onnikka app is a self-guided, mobile-based intervention that draws on persuasive design, cognitive behavioural therapy and acceptance and commitment therapy. The app includes, for example, educational content, exercises and self-assessment, as well as tools for self-monitoring weight, eating, physical activity and motivation. Participants in the study did not receive face-to-face lifestyle counselling in addition to the app.
According to the researchers, the findings suggest that a self-guided mobile app could be one way of supporting changes in eating behaviour as part of obesity treatment. However, the study does not show that the intervention would work in the same way for everyone.
“Obesity has individual underlying factors, and different people may benefit from different treatment approaches,” says doctoral researcher Silja Rantaiso.
The study was published in the peer-reviewed journal International Journal of Obesity on 31 July 2026.
Research article in the International Journal of Obesity
Onnikka has been developed and studied at the University of Oulu for more than 15 years. Onnikka Health Oy, a spin-off company of the University of Oulu established to develop the method, is responsible for commercialising the mobile version of Onnikka and making it widely available to healthcare organisations. Onnikka can be accessed through healthcare providers in Finland. Onnikka is also available in Sweden and Norway.