Brain-derived neurotrophic factor (BDNF) is a protein involved in the growth, maturation, and survival of nerve cells in the brain. It plays a vital role in learning and memory and is critical for cell-to-cell neuronal communication within synapses (Castrén & Monteggia, 2021). In the context of the diet-mental health relationship (DMHR), a healthy and nutritious diet elevates the level of BDNF, resulting in improved metabolic and cognitive health.