Nutrition is not merely about food intake; it is about how the human body acquires, transforms and utilises nutrients to sustain life, productivity and resilience. Malnutrition emerges when this finely tuned biological and social process breaks down — due to deficiency, excess or imbalance. Understanding nutrition through the lenses of micronutrients, metabolism and public health is crucial for addressing India’s persistent yet evolving nutritional challenge.
Micronutrients: Small inputs, large consequences
Micronutrients — vitamins and minerals — are required in minute quantities, but their physiological impact is disproportionate. They act as co-factors, hormones, antioxidants and structural elements, enabling core bodily functions.
Iron is essential for haemoglobin synthesis; its deficiency leads to anaemia, reducing work capacity, cognitive performance and maternal health outcomes.Iodine regulates thyroid hormones; deficiency during pregnancy can cause irreversible intellectual disability.Vitamin A supports vision and immune integrity; its lack increases susceptibility to infections and childhood mortality.Zinc and Folate influence cell division, immunity and foetal development.
Micronutrient deficiencies are often termed “hidden hunger” because caloric sufficiency may coexist with nutrient inadequacy. In India, cereal-heavy diets, low dietary diversity, poor absorption due to infections and gender-based food allocation exacerbate this silent crisis.
Metabolism: Where nutrition becomes biology
Metabolism is the biochemical engine that converts food into energy, tissues and regulatory molecules. It has two interlinked dimensions:
Catabolism: Breakdown of carbohydrates, fats and proteins to release energy (ATP).
Anabolism: Utilisation of energy for growth, repair and synthesis of enzymes and hormones.
Micronutrients are indispensable to metabolism. For instance:
B-complex vitamins act as coenzymes in energy pathways.Iron and copper enable cellular respiration.Magnesium and zinc regulate enzyme activity.
Malnutrition disrupts metabolism in a cyclical manner. Undernutrition lowers basal metabolic rate, weakens immunity and increases vulnerability to infections, which in turn impair nutrient absorption — creating a vicious biological trap. Conversely, excessive intake of sugars and fats alters insulin metabolism, contributing to obesity, diabetes and cardiovascular diseases.
Malnutrition as a public health challenge
From a public health perspective, malnutrition is not an individual failure but a systemic outcome shaped by poverty, sanitation, education, healthcare access and food systems.
India today faces a triple burden of malnutrition:
Undernutrition: Stunting, wasting and underweight in children.Micronutrient deficiencies: Anaemia, vitamin and mineral inadequacies across age groups.Overnutrition: Rising obesity and non-communicable diseases due to sedentary lifestyles and ultra-processed foods.
This paradox reflects structural transitions — urbanisation, changing diets, climate stress on agriculture and unequal access to nutritious food. Women and children remain the most vulnerable due to intergenerational transmission of malnutrition and social inequities.
Integrating nutrition science with policy action
Effective nutritional intervention must move beyond food quantity to nutritional quality and absorption. Key public health strategies include:
Diet diversification through millets, pulses, fruits and animal-source foods.Fortification and biofortification to address widespread micronutrient gaps.Life-cycle approach focusing on the first 1,000 days (conception to early childhood).Nutrition-sensitive sectors — sanitation, drinking water, education and women’s empowerment.
Scientific understanding of nutrition strengthens policy design by aligning biological needs with social delivery mechanisms.
Nutrition as foundation of human capital
Nutrition lies at the intersection of biology and governance. Micronutrients sustain metabolic processes, metabolism determines physical and cognitive outcomes and public health systems translate knowledge into population-level impact. Addressing malnutrition is therefore not only a welfare imperative but a strategic investment in human capital, productivity and national development.
For UPSC Mains, nutrition questions demand integration — linking science with socio-economic realities and policy responses. This interdisciplinary framing provides that analytical edge.
