Human appetite is not driven solely by physiological hunger. Psychological states, neurochemical signaling, and dietary habits all form a dynamic system that governs how and why we eat. Understanding this relationship is crucial not just for nutrition science, but also for mental health and public health interventions.
1. Psychological State and Its Impact on Appetite
Stress and Anxiety
Acute stress activates the hypothalamic-pituitary-adrenal (HPA) axis, increasing cortisol, which can either suppress or stimulate appetite depending on the individual.
Chronic stress is often linked to emotional eating, especially the consumption of "comfort foods" high in sugar and fat.
Depression
Some individuals experience anorexia (loss of appetite), while others may develop hyperphagia (increased appetite), particularly craving carbohydrate-rich foods due to serotonin modulation.
Positive Emotions
Joy and social connection often enhance appetite, especially in communal or celebratory settings. Dopaminergic pathways reward shared eating experiences.
2. How Food Composition Influences Mood and Mental Health
Carbohydrates
Increase tryptophan transport across the blood-brain barrier, enhancing serotonin synthesis—associated with mood elevation and satiety.
Omega-3 Fatty Acids
Found in fatty fish (e.g., salmon, sardines), they exhibit anti-inflammatory properties and modulate neurotransmission. Clinical trials show beneficial effects in depression and cognitive function.
Micronutrients

B-vitamins, zinc, magnesium, and iron are essential for neurotransmitter production. Deficiencies have been associated with mood disorders.
Caffeine and Sugar
While they can provide temporary boosts in mood or alertness, their overuse may contribute to anxiety, irritability, and eventual mood crashes.
3. Hormonal & Neurochemical Mediators of Appetite and Emotion
Hormone/Neurotransmitter Role in Appetite Regulation Role in Mood
Ghrelin Hunger signal from the stomach Linked with anxiety and exploratory behavior
Leptin Satiety signal, released from adipose tissue Affects cognition and emotional regulation
Serotonin Promotes satiety when elevated Regulates mood, anxiety, and happiness
Dopamine Triggers craving and reward-seeking Central to motivation and pleasur

4. Lifestyle Factors: Sleep and Stress
Sleep deprivation raises ghrelin and lowers leptin, increasing hunger and cravings.
Chronic stress disrupts appetite-regulating hormones, contributing to disordered eating patterns.
5. Dietary Patterns and Mental Resilience
Mediterranean-style diets, rich in whole grains, vegetables, olive oil, and fish, are linked to lower rates of depression and anxiety.
Ultra-processed foods, on the other hand, have been associated with increased inflammation and mood instability.
Clinical and Research Implications
Understanding the bidirectional link between mood and nutrition can help:
 Design dietary interventions to support mental health.
 Create personalized nutrition plans based on psychological profiles.
 Develop public health strategies that integrate mental health and nutritional


جامعة المستقبل الجامعة الأولى في العراق
كلية الصيدلة الأولى على الكليات الأهلية