In the United States, more than 42% of adults have obesity. A new trial reports that participants with obesity who received no intervention other than undergoing regular body weight assessments did not gain weight over a 3-year period. This finding suggests that regular monitoring alone may be effective in preventing weight gain.
The prevalence of overweight and obesity emphasizes just how difficult it is to achieve long-term weight loss and how few strategies to reduce obesity have been successful.
Part of the challenge of achieving long-term weight loss is maintaining the significant behavioral changes required.
Indeed, studies show that weight loss generally declines in the 1–2 years following the initial intervention.
In recognition of this, a new study trialed smaller changes to lifestyle as a way of achieving lasting weight loss in people with overweight or obesity.
The findings of the randomized controlled trial, which involved 320 adults, appear in the Canadian Medical Association Journal.
The ‘small change’ approach
The trial tested a small change approach to preventing weight gain, which consisted of a reduction in calorie intake of 100 calories each day — which is roughly equivalent to a medium-sized banana — combined with an increase in physical activity of 2,000 steps per day.
Prof. Becca Krukowski, a professor in the Department of Public Health Sciences at the University of Virginia in Charlottesville and an expert in behavioral weight management, explained the approach to Medical News Today:
“Weight loss through larger changes is often associated with weight regain, so some argue that the goal should instead be weight stability. The thought is that small changes may be more palatable and sustainable for the broader population, rather than large changes.”
The scientists randomly assigned half of the participants to the small change approach and the other half to monitoring alone. The monitoring alone intervention consisted only of regular body weight monitoring by healthcare professionals.
The interventions lasted for 2 years, with the healthcare professionals monitoring the participants’ body weight for a further year.
In the early stages of the intervention, the participants in the small change group lost significantly more weight than those in the monitoring alone group.
At 15 months, those in the small change group had lost 1.6 kilograms (kg) on average, compared with 0.3 kg in the monitoring alone group.
However, by the end of the 2-year study, the changes were no longer significant. There was also no significant difference in body weight at the 3-year follow-up.
Although the study suggests that a small change approach may be no more effective than weight monitoring, both strategies were associated with weight gain prevention.
People in the monitoring group actually lost weight — 0.7 kg on average after 3 years — which was a surprising result for the team.
“Our hypothesis was that, as we see in the general population over 3 years, people with overweight and obesity will gain weight,” lead author of the study Dr. Robert Ross explained to MNT. Dr. Ross conducts research on weight management at the School of Kinesiology and Health Studies and the School of Medicine at Queen’s University, Canada.
The fact that participants did not gain weight during this period is important, as even small gains in weight (0.5 to 1 kg each year) are associated with adverse health outcomes in people with overweight and obesity.
As to why this happened, the authors speculate that people who enroll in a trial for weight management may already have some commitment to behavioral changes. Another possibility, they write, is that the effect of regular weight monitoring itself may have influenced the participants’ behavior during the trial.
Prof. Krukowski told MNT that this matches her experience, too. “I believe that participants, particularly those that express interest in a behavioral weight management trial, feel accountable to the staff who conduct these weigh-ins and likely modify their eating and exercise behaviors to prepare for these weigh-ins.”
Monitoring as a strategy to prevent weight gain
Going forward, Dr. Ross and his team plan to use these insights to assess whether weight monitoring itself could be an effective means of preventing weight gain.
“Our behavioral colleagues think that there’s some great potential here, especially for people with overweight. If we could prevent the transition from the overweight category to the obese category, that would be a real advance,” he said.
The team is hard at work planning a new trial to investigate this strategy. “We need to do a larger, multicenter trial to investigate whether monitoring alone might be associated with the prevention of weight gain. We’re giving this a lot of thought at the moment. Hopefully, in the next year or so, we will submit an application, get the funding, and start that trial.”