A mobile phone-based intervention that was designed to slow weight regain in obese people who had initially lost weight was no more effective than usual care, in a UK trial*. The study authors, led from the University of Newcastle upon Tyne, said in PLOS Medicine that although the intervention was associated with increased physical activity and self-weighing, weight-loss maintenance (WLM) was similar in both groups.
The researchers explained that so far, scalable WLM interventions for adults with obesity have been lacking – but they are “vital for the health and economic benefits of weight loss to be fully realised”. So, they set up the NULevel trial to examine the effectiveness and cost-effectiveness of a mobile phone-based intervention to support WLM in adults with obesity after clinically significant weight loss.
They randomised 288 self-selected adults with a pre-weight loss body mass index (BMI) of ≥30kg/m2, and weight loss of at least 5% in the previous 12 months, to either standard lifestyle advice through a newsletter (control arm) or a technology-mediated low-intensity behavioural WLM programme (intervention arm). The intervention comprised a single face-to-face goal-setting meeting, self-monitoring, and remote feedback on weight, diet, and physical activity via links embedded in short message service. They gave all participants wirelessly connected weighing scales – but instructed only those in the intervention arm to weigh themselves daily, and told them that they would receive feedback on their weight.
Among the 264 participants who completed the trial, mean weight gain from baseline to 12 months was 1.8kg in both the intervention and control groups. However, intervention participants weighed themselves more frequently than control participants; they were more physically active; and they reported greater satisfaction with weight outcomes, more planning for dietary and physical activity goals and for managing lapses, and greater confidence for healthy eating, weight loss, and WLM.
The study authors noted potential limitations of their study, for example the use of connected weighing study in both trial arms, which they suggested “might have acted as an active intervention in the control arm”, as well as the absence of a measurement of energy intake, and the recruitment from just one UK region. They added that they had found no evidence that the intervention was cost-effective.
They concluded: “Amongst individuals with obesity, we found no evidence of effectiveness of a remotely delivered, low-intensity behavioural intervention based on self-regulation theory in reducing weight regain compared to standardised lifestyle advice and independently achieved, clinically significant weight loss for individuals who received a set of wirelessly connected weighing scales. The NULevel intervention improved various hypothesised mediators compared to the control arm, including physical activity and self-weighing, but no differences in WLM.
“We conclude that the incremental dose of the NULevel intervention over the active control condition might have been insufficient to affect weight outcomes. This research should inform future intervention design decisions regarding delivery modality and intensity.”
*Sniehotta FF, Evans EH, Sainsbury K, et al. Behavioural intervention for weight loss maintenance versus standard weight advice in adults with obesity: A randomised controlled trial in the UK (NULevel Trial). PLoS Med 2019; 16(5): e1002793. DOI:10.1371/journal.pmed.1002793