Nutritional neuroscience is the scientific discipline that studies the effects various components of the diet such as minerals, vitamins, protein, carbohydrates, fats, dietary supplements, synthetic hormones, and food additives have on neurochemistry, neurobiology, behavior, and cognition.

Research on nutritional mechanisms and their effect on the brain shows they are involved in almost every facet of neurological functioning, including alterations in neurogenesis, neurotrophic factors, neural pathways and neuroplasticity, throughout the life cycle.

Relatively speaking, the brain consumes an immense amount of energy in comparison to the rest of the body. The human brain is approximately 2% of the human body mass and uses 20–25% of the total energy expenditure. Therefore, mechanisms involved in the transfer of energy from foods to neurons are likely to be fundamental to the control of brain function. Insufficient intake of selected vitamins, or certain metabolic disorders, affect cognitive processes by disrupting the nutrient-dependent processes within the body that are associated with the management of energy in neurons, which can subsequently affect neurotransmission, synaptic plasticity, and cell survival.

Deficiency or excess of essential minerals (e.g. iron, zinc, copper, and magnesium) can disrupt brain development and neurophysiology to affect behavior. Furthermore, minerals have been implicated in the pathophysiology of neurodegenerative diseases including Alzheimer's dementia.

Iron is essential for several critical metabolic enzymes and a deficiency of this mineral can disrupt brain development. For, example chronic marginal iron affects dopamine metabolism and myelin fatty acid composition and behavior in mice. In rats a marginal iron deficiency that does not cause anemia disrupted axon growth in the auditory nerve affecting auditory brainstem latency without major changes in myelination. In rhesus macaques, prenatal iron deficiency disrupts emotional behavior and polymorphisms that reduce the expression of monoamine oxidase interact with gestational iron deficiency to exacerbate the response to a stressful situation leading to increased aggressiveness. Inexpensive and effective iron supplementation is an available preventive strategy recommended by the World Health Organization. However, iron supplementation can exacerbate malaria infection. Therefore, individuals receiving iron supplementation in malaria-endemic areas must be carefully monitored.

Zinc is essential for the structure and function of thousands of proteins critical for the function of every cell. Zinc can also serve as a neurotransmitter in the brain, thus a deficiency of this mineral can clearly disrupt development as well as neurophysiology. For example, zinc deficiency during early development impairs neurogenesis leading to memory impairments. However, zinc deficiency later in life can disrupt appetite and cause depression-like behavior. However, it is important to consider copper intake relative to zinc supplementation because excess zinc can disrupt copper absorption.

Conservative estimates suggest that 25% of the world's population is at risk of zinc deficiency.

Hypozincemia is usually a nutritional deficiency, but can also be associated with malabsorption, diarrhea, acrodermatitis enteropathica, chronic liver disease, chronic renal disease, sickle cell disease, diabetes, malignancy, pyroluria, and other chronic illnesses. It can also occur after bariatric surgery, heavy metal exposure and tartrazine. ^{[citation needed]}