During pregnancy, physiological and psychological factors influence eating behaviour and food preferences. Food cravings are common in pregnancy and contribute to excessive gestational weight gain (GWG). Excessive GWG is present across all body mass index (BMI) categories and is associated with adverse outcomes. Outside of pregnancy, highly palatable food cues activate brain regions involved in reward and attention, which may influence eating behaviour and behavioural responses. However, brain and behavioural responses to food cues across pregnancy, and their association with psychological and metabolic factors, remain poorly understood. This study aims to investigate spatiotemporal brain responses to visual food cues across individuals with different BMI categories and their associations with behavioural, psychological and metabolic outcomes during pregnancy.

This is a prospective observational cohort study conducted at the Lausanne University Hospital, Switzerland. 94 pregnant individuals (47 healthy normal weight and 47 with overweight/obesity) will be assessed at 12–16 and 31–36 weeks of gestational age from November 2024 to September 2026. Data collected for the primary outcomes include electroencephalography-based brain responses to validated visual food cues varying in fat and carbohydrate content, behavioural responses to the same cues using a gamified smartphone Go/NoGo task. Secondary validated outcomes include heart rate variability (Actiheart), body composition (InBody S10), glycated haemoglobin (Afinion), cardiorespiratory fitness (The Chester step test), snack intake, eating behaviour (Intuitive Eating Scale-2, Three-Factor Eating Questionnaire-Revised), food cravings (Food Craving Questionnaire-state), mood and depressive symptoms (Edinburgh Postnatal Depression Scale). Statistical analyses include group comparisons, longitudinal analyses and regression models adjusted for potential sociodemographic/medical confounders.

All participants will provide written informed consent. The Human Research Ethics Committee of the Canton de Vaud approved the study protocol (CER-VD 2023-01462). Findings will be disseminated through peer-reviewed publications, (inter)national conferences and shared with healthcare professionals and stakeholders to inform strategies for improving maternal health.