New research shows weight loss interventions may improve disordered eating symptoms

A new systematic review has found that weight loss interventions, including behavioural programmes and pharmacotherapy, may improve symptoms of disordered eating in individuals with overweight or obesity.

This discovery challenges long-standing concerns that intentional weight loss efforts could trigger or worsen eating disorders, particularly in vulnerable populations. Eating disorders are among the most severe psychiatric conditions, with high rates of morbidity and mortality. Globally, their prevalence is increasing, with lifetime rates around 8 per cent for women and 2 per cent for men, figures that have doubled since the early 2000s. Simultaneously, adult obesity rates have surged, affecting an estimated 250 million people worldwide as of 2022. Obesity significantly raises the risk of non-communicable diseases like type 2 diabetes, cardiovascular disease, and several cancers.

The intersection of these health issues is complex. Disordered eating, particularly binge eating, is more prevalent among people living with obesity. Some theories suggest that attempts at weight loss may trigger eating disorders, while others point to shared genetic and psychological risk factors as the root cause.

To clarify the relationship between weight loss interventions and disordered eating, researchers conducted a systematic review and meta-analysis. They analysed data from 38 studies, encompassing 66 intervention arms and 3,364 participants. The interventions included behavioural weight loss programmes, pharmacotherapy, and combinations with psychological support, lasting at least four weeks.

Key findings included an average weight loss of 4.7 kg (95% CI: -5.7, -3.7) and a significant improvement in disordered eating symptoms, with standardised mean differences (SMD) of -1.47 (95% CI: -1.67, -1.27, p < 0.001) at a median follow-up of four months. In seven randomised trials comparing weight loss interventions to minimal or no intervention, disordered eating symptoms improved by -0.49 SMD units (95% CI: -0.93, -0.04, p = 0.0035).

Subgroup analyses also revealed that individuals with pre-existing eating disorders experienced greater improvements in symptoms.

These findings suggest that weight loss interventions do not inherently worsen disordered eating symptoms and may even provide benefits, particularly for those with baseline disordered eating. This could reshape clinical approaches, encouraging integrated treatment strategies that address both weight management and mental health.

However, the high variability (I2 = 94 per cent) among studies highlights the need for further research to refine these insights and guide best practices in obesity and eating disorder management.