Background: Hunger is commonly linked to negative mood, and mood shifts are believed to arise from sensing the body's internal state. However, it remains unclear whether this link is driven by subconscious effects of circulating glucose levels or by consciously sensed metabolic states. Here, we test whether glucose levels directly influence mood or indirectly via subjective ratings of metabolic state.
Methods: In this observational cohort study, 90 healthy adults (female = 46; male = 44) were continuously monitored throughout the day using interstitial glucose sensors for four weeks while completing ecological momentary assessments up to twice per day (EMA; M = 48 assessments per participant) to rate mood and perceived metabolic states.
Findings: As expected, hungry participants reported lower mood, and metabolic state ratings were associated with glucose levels. Although glucose levels were associated with mood, the metabolic state ratings mediated this association. Individual differences reflecting metabolic health (i.e., BMI and insulin resistance) did not affect the interaction between glucose and metabolic state ratings on mood. Notably, individuals with higher interoceptive accuracy had fewer fluctuations in mood ratings.
Interpretation: We conclude that hunger-related mood shifts depend on conscious sensing of the body's internal state instead of acting subconsciously. Our study highlights the relevance of considering the self-report of bodily signals in understanding mood shifts, offering new fundamental insights into mood regulation mechanisms.
Funding: The study was supported by the German Research Foundation (DFG) grants KR 4555/7-1, KR 4555/9-1, KR 4555/10-1, and DE 2319/22-1.
Keywords: Continuous glucose monitoring; Ecological momentary assessment; Interoception; Longitudinal.
Copyright © 2025 The Author(s). Published by Elsevier B.V. All rights reserved.