The stability of brain functions is mainly determined by the energy management of the cells, and mental health is, therefore, profoundly affected by metabolic dysfunctions and immune and inflammatory processes. Research sheds light on more and more details and connections about the efficacy of diet and exercise, based on which we can develop effective metabolic interventions. The roots of this discipline, which is emerging today, go back to thousands of years of traditions and hundreds of years of documented observations. This paper reviews the role of mitochondria in healthy cell functions, in the distress cascade, and in the neurobiology of mental illnesses, as well as the modern knowledge related to metabolic interventions that support mitochondrial function, the therapeutic fasting, the ketogenic diet therapy, the regular exercise, and the use of nutritional supplements, and finally discusses the role of metabolic interventions in curing psychiatric diseases and improving mental health. The purpose of metabolic psychiatric interventions is to prevent neuroprogression in the broad sense, if it is already developing, to stop it, to break it, to restore the degraded functions, as a supplement to the usual psychosocial, pharmacological, somatic and neuromodulation treatments.