Mediterranean Diet Shifts Food Preferences and Eating Behaviors Without Altering Appetite Hormones or Glucose Homeostasis
Background
Individuals at high risk of metabolic disease often struggle with unhealthy eating behaviors and food preferences, contributing to conditions like obesity and type 2 diabetes. Current interventions frequently target appetite regulation and glucose homeostasis through pharmacological means, but the impact of dietary patterns on these physiological markers alongside behavioral changes remains less clear. Understanding how a healthy diet, such as the Mediterranean dietary pattern, influences subjective appetite, satiety hormones (e.g., ghrelin, GLP-1, PYY), adipokines (e.g., leptin, adiponectin), and glucose metabolism is crucial for developing effective, sustainable lifestyle interventions.
Study Design
This study, nested within the He Rourou Whai Painga (HRWP) trial, enrolled adults with a high risk of metabolic disease (MetSSS score ≥ 0.35). Participants underwent a 12-week dietary intervention following a Mediterranean dietary pattern. Before and after the intervention, participants completed a mixed-meal challenge. Subjective appetite sensations were measured using Visual Analogue Scales (VAS). Eating behaviors and food preferences were assessed via the Three Factor Eating Questionnaire (TFEQ) and Leeds Food Preference Questionnaire (LFPQ). Blood samples were collected fasting and at 15, 30, 60, 90, and 120-min post-meal to analyze concentrations of adiponectin, ghrelin, leptin, peptide YY (PYY), glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP), fibroblast growth factor 21 (FGF21), growth differentiation factor 15 (GDF15), glucose, insulin, and C-peptide.
Results
The 12-week Mediterranean diet intervention significantly altered eating behaviors and food preferences. Participants exhibited a significant decrease in uncontrolled eating (UE) scores (p value = 0.0226) and a notable increase in cognitive restraint (CR) scores (p value = 0.0004). Furthermore, the intervention led to a significant reduction in implicit desire for high-fat savoury foods, low-fat savoury foods, and overall fat-appeal bias.
Despite these significant behavioral shifts, none of the measured peptides (including adiponectin, ghrelin, leptin, PYY, GLP-1, GIP, FGF21, GDF15) or other metabolic markers (such as glucose, insulin, and C-peptide) showed statistically significant changes after the 12-week dietary intervention. Although glucose, insulin, and C-peptide levels numerically decreased, these reductions did not reach statistical significance, indicating a dissociation between observed behavioral changes and measured physiological markers in this cohort.
Key Findings
- Uncontrolled eating (UE) significantly decreased (p value = 0.0226) after 12 weeks of Mediterranean diet.
- Cognitive restraint (CR) significantly increased (p value = 0.0004) following the intervention diet.
- Implicit desire for high-fat savoury foods was significantly reduced after the intervention.
- Implicit desire for low-fat savoury foods and fat-appeal bias were significantly reduced.
- None of the measured peptides (e.g., ghrelin, GLP-1, leptin) or metabolic markers (e.g., glucose, insulin) changed significantly.
Why It Matters
This study highlights that a Mediterranean diet can effectively modify eating behaviors and food preferences, even without detectable changes in key appetite-regulating hormones or glucose metabolism. For individuals at risk of metabolic disease, this suggests that dietary interventions can foster healthier habits by targeting psychological and behavioral aspects of eating, rather than solely relying on physiological shifts. The practical takeaway is that dietary changes can drive significant behavioral improvements, such as reduced uncontrolled eating and decreased desire for high-fat foods, independent of immediate hormonal or metabolic marker alterations. This finding supports the value of sustained dietary patterns in promoting long-term health, emphasizing the importance of behavioral strategies in diet-based protocols. Future research should explore the underlying mechanisms driving these behavioral changes in the absence of measurable hormonal shifts, potentially focusing on neural reward pathways or gut microbiome interactions.
mediterranean-diet
eating-behavior
food-preferences
metabolic-disease
appetite-regulation
hormones