The research, led by Nour Amin Elsahoryi of the University of Petra in Jordan together with colleagues across Jordan, Malaysia, Tunisia, Germany, and Bahrain, set out to do something unusually comprehensive: to phenotype night eating syndrome across body composition, blood chemistry, appetite-regulating hormones, psychological symptoms, and eating behavior, all within a single clinical cohort. The population studied was also notable. Middle Eastern populations remain dramatically underrepresented in eating disorder research, and this investigation offers one of the most detailed metabolic portraits of the condition in that region to date.

The team recruited eighty adults who had sought help for nocturnal eating concerns. The participants were young, with a median age of just twenty-one years, and predominantly female, making up eighty-five percent of the sample. Each volunteer underwent a battery of assessments: bioelectrical impedance analysis to measure body composition, fasting blood draws for biochemical assays, a twenty-four-hour dietary recall to capture eating patterns, and a suite of validated Arabic-language questionnaires covering mood, sleep, and eating behavior.

To classify participants, the researchers used the Night Eating Questionnaire, a widely applied screening instrument. Anyone scoring twenty-five or above was placed in the night eating syndrome screening-positive group, which amounted to thirty-eight people, or 47.5 percent of the cohort. The remaining forty-two participants formed the comparison group. This threshold-based approach allowed the investigators to compare the two clusters across dozens of biological and psychological variables, then apply rigorous statistical controls to ensure the differences they found were not statistical noise.

The metabolic contrasts were striking. Participants screening positive for the syndrome had a median body mass index of 27.80 kilograms per square meter, compared with 20.65 in the comparison group, and their median visceral fat level was more than double, at 14.00 versus 6.50. Visceral fat, the metabolically active fat wrapped around internal organs, is among the most dangerous forms of adiposity, strongly linked to insulin resistance and cardiovascular disease. Finding it elevated in a cohort whose median age is twenty-one is a warning sign that the metabolic consequences of disordered night eating may begin early in adult life.

The blood work told a consistent story. Leptin, the hormone released by fat cells that signals energy stores to the brain, was fifty-two percent higher in the night eating group. Insulin concentrations were fifty percent higher, and estimated insulin resistance, calculated using the homeostatic model assessment, was thirty-nine percent higher. Elevated leptin alongside increased fat mass suggests a state of leptin elevation consistent with greater adiposity rather than a primary signaling defect, but the insulin findings point toward genuine metabolic strain. Even more provocative were the inflammatory markers: C-reactive protein, a liver-produced sentinel of systemic inflammation, was fifty-eight percent higher, and interleukin-6, a cytokine that drives inflammatory signaling throughout the body, was fifty-one percent higher. All of these differences survived the Benjamini-Hochberg false-discovery-rate correction, a statistical procedure designed to keep false positives in check when many comparisons are made simultaneously.

The psychological and behavioral profile of the screening-positive group was equally concerning. Median scores for depression, anxiety, and stress, measured with the DASS-21 scales, were all significantly higher than in the comparison group, as were scores for emotional eating and insomnia severity. Every one of these differences remained statistically significant after multiplicity adjustment, with adjusted p-values at or below 0.002. This convergence of mood disturbance, poor sleep, and emotion-driven eating suggests that night eating syndrome sits at the intersection of mental health and metabolism, rather than belonging cleanly to either domain.

To identify which factors were independently associated with night eating status, the researchers ran an exploratory binary logistic regression, a technique that estimates the unique contribution of each variable while holding the others constant. Five factors emerged: emotional eating, smoking, body mass index, insomnia severity, and depressive-symptom severity. The picture that emerges is of a syndrome sustained by a web of interacting influences, where emotional distress drives eating, disrupted sleep reinforces abnormal eating rhythms, and increasing body weight feeds back into both the metabolic and psychological burden. Smoking, too, appeared as an independent correlate, hinting that health behaviors cluster in ways that compound risk.

The authors are careful, and rightly so, about what the study cannot show. Because every participant was assessed at a single point in time, the design is cross-sectional and cannot establish causality or temporal ordering. It is entirely possible that metabolic and inflammatory changes drive night eating, that night eating drives the metabolic changes, or that a third factor, such as chronic stress or circadian disruption, produces both. Elevated interleukin-6, for example, is known to influence both appetite regulation and sleep architecture, making it a plausible common pathway. Longitudinal studies that follow individuals over months and years will be needed to untangle the direction of these relationships, and the researchers explicitly call for such work.

Even with those caveats, the clinical implications are hard to ignore. If night eating syndrome is accompanied by measurable insulin resistance, visceral fat accumulation, and systemic inflammation in people barely old enough to have finished university, then early identification matters enormously. The findings support an integrated approach to care, one that combines emotional regulation support, smoking cessation, sleep-focused interventions, mental health treatment, and metabolic assessment when clinically indicated. They also underscore the need for culturally appropriate screening tools and care pathways in Middle Eastern populations, where evidence on eating disorders remains thin. What this study delivers is a detailed biological fingerprint of a condition too often dismissed as a simple habit, and it makes a compelling case that the kitchen light left on at midnight may be illuminating the early stages of a genuine metabolic-inflammatory disorder.

Subject of Research: Night eating syndrome and its metabolic, inflammatory, and psychological correlates in young adults

Article Title: Night eating syndrome as a metabolic-inflammatory disorder: comprehensive phenotyping through a cross-sectional analytical study in middle eastern young adults

Article References: Elsahoryi, N. A., Alhaj, O. A., Kaur, S., Trabelsi, K., Ammar, A., & Jahrami, H. (2026). Night eating syndrome as a metabolic-inflammatory disorder: comprehensive phenotyping through a cross-sectional analytical study in middle eastern young adults. Journal of Eating Disorders. https://doi.org/10.1186/s40337-026-01789-2

Image Credits: AI Generated

DOI: 10.1186/s40337-026-01789-2

Keywords: night eating syndrome, eating disorders, insulin resistance, leptin, inflammation, visceral fat, emotional eating, insomnia, depression, obesity, Middle East, metabolic health