Nutrition is fundamental for health. Energy and nutrients are sensed by complex mechanisms at the cellular level (energy/nutrient sensing) and this information is analysed by the integrated neuroendocrine system which in turn coordinates appropriate metabolic responses. This dimension reflects the importance of understanding the impact of specific nutrients on biological responses when we design nutritional interventions (usually in combination with exercise regiments) for weight or diabetes prevention and management. Research is ongoing and new findings continually enrich our knowledge on nutritional management, however many relevant aspects are still on scientific debate. Regardless, caloric restriction and avoidance of excessive carbohydrate consumption are fundamental for the development of meaningful nutritional strategies for the prevention and management of chronic metabolic imbalances.