Insomnia versus daytime sleepiness: distinct behavioural phenotypes of mood and binge eating in adults with clinical obesity

Background/Objectives. Insomnia and excessive daytime sleepiness are common in adults with obesity but typically examined in isolation. We tested whether, jointly, they identify behavioural phenotypes with distinct eating and mood profiles. Subjects/Methods. Cross-sectional analysis of 2,016 adults from the Montpellier Obesity Care Cohort (MOCC) (76% women; mean BMI 37.1 kg/m²). Participants completed the Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), Binge Eating Scale (BES), Hospital Anxiety and Depression Scale (HADS), Perceived Stress Scale, and Intuitive Eating Scale-2 (IES-2). Four phenotypes were defined a priori using ISI ≥ 15 and ESS ≥ 11: good sleeper, isolated insomnia, isolated sleepiness, combined. Multivariable regressions were adjusted for age, sex and BMI. Results. Phenotype distribution was 53.6% good sleeper, 18.2% isolated insomnia, 13.8% isolated sleepiness, 14.4% combined. ISI and ESS were only moderately correlated (ρ = 0.30). Isolated insomnia was most strongly associated with anxiety (HAD-A ≥ 11: adjusted OR [aOR] 4.48, 95% CI 3.41–5.89) and depression (aOR 3.09, 2.20–4.33); isolated sleepiness was most strongly associated with severe binge eating (BES ≥ 27: aOR 2.55, 1.69–3.83) and lower intuitive eating (IES-2 β = − 0.24, − 0.33 to − 0.15). The combined phenotype carried the highest risk overall. BMI did not differ across phenotypes. Findings were robust to OSA exclusion and to alternative insomnia thresholds. Conclusions. Insomnia and daytime sleepiness identify distinct behavioural phenotypes in clinical obesity, independently of BMI. Joint screening at intake may help personalise behavioural obesity management.