The First Pharmacotherapy With Real Evidence for Binge Eating: LDX Meta-Analysis Across 988 Patients
- Lisdexamfetamine (LDX) significantly reduced binge-eating days by 1.29 per week compared to placebo across 5 RCTs and 988 participants — clinically meaningful for patients bingeing 4–5 days/week
- Obsessive-compulsive binge-eating behaviors (Y-BOCS-BE) decreased by 6.16 points — the compulsive drive to binge, not just the behavior, is reduced
- Significant weight reduction (SMD = −1.31) — addressing the medical comorbidity that often motivates treatment-seeking
- Diarrhoea identified as a significant side effect (RR = 4.06) not previously acknowledged in guidelines — a safety signal the field has been underreporting
Binge-eating disorder (BED) is the most prevalent eating disorder and has the weakest pharmacotherapy evidence base. SSRIs show modest effects. Topiramate works but the side effect profile limits use. LDX — a prodrug stimulant approved for ADHD and BED in the US — now has its evidence pooled across all available RCTs. The signal is clear and clinically significant.
What the numbers mean in practice
A reduction of 1.29 binge days per week translates differently depending on the patient's baseline. For someone bingeing 5 days per week, this is a 26% reduction from medication alone — before any psychotherapy is added. For someone bingeing 3 days per week, this is a 43% reduction. The Y-BOCS-BE decrease of 6.16 points matters separately: it measures the obsessive preoccupation and compulsive urge that drive the behavior. LDX addresses the cognitive loop, not just the eating event.
The mechanism question
LDX enhances dopaminergic and noradrenergic activity — improving impulse control and modifying the reward pathway that makes bingeing self-reinforcing. This is why it works for both ADHD and BED: both involve impaired inhibition in the context of reward sensitivity. The weight reduction is a secondary effect — appetite suppression plus reduced binge frequency produces caloric deficit.
The safety signal
The meta-analysis identifies diarrhoea as a significant adverse effect (RR = 4.06) that previous guidelines did not acknowledge. This is not trivial: GI side effects reduce adherence, and for BED patients who already have complicated relationships with eating and digestion, unreported GI effects can trigger dropout. Clinicians should proactively discuss this with patients starting LDX.
For your practice
If you treat BED: LDX now has pooled evidence across 988 patients. Consider it for patients with moderate-to-severe binge frequency, particularly those with comorbid ADHD features (impulsivity, attention difficulties) or when psychotherapy alone has been insufficient. Start the conversation about diarrhoea as a potential side effect — proactive disclosure improves adherence. Combine with CBT-E or behavioral interventions for the best outcomes — pharmacotherapy addresses the impulse; therapy addresses the pattern.
LDX does not just reduce binge eating. It reduces the obsessive preoccupation that makes the patient plan their next binge while still ashamed of the last one.
Only 5 RCTs available. Industry-funded trials predominate. Short-term follow-up (12–16 weeks typical). LDX is a controlled substance with abuse potential — not suitable for all patients. The diarrhoea signal needs confirmation in larger real-world studies.