Obesity as Malnutrition: Exposing the Hidden Nutrient Deficiency Behind Excess Weight

Background: Malnutrition is no longer confined to undernutrition; it now coexists with obesity, a phenomenon known as the double or triple burden of malnutrition. In this condition, energy-dense but nutrient-poor diets drive both excessive fat accumulation and “hidden hunger” caused by micronutrient deficiencies. Objectives: To review the prevalence of micronutrient deficiencies (iron, vitamin D, vitamin B12, zinc) among obese individuals; to examine dietary patterns and lifestyle factors linked to obesity-related malnutrition; to explore associated physiological and metabolic consequences; and to evaluate current interventions and policy measures. Methods: A thematic narrative review has been prepared using peer-reviewed literature from PubMed, Scopus, Web of Science, and Google Scholar published between 2010 and 2024. Key Findings: Evidence shows high prevalence of vitamin D deficiency (57–94%), along with iron, zinc, and vitamin B12 deficiencies among obese populations. Excessive consumption of ultra-processed foods, physical inactivity, socio-economic shifts, and urbanized lifestyles were major contributing factors. Hormonal dysregulation, insulin resistance, and chronic low-grade inflammation were identified as key metabolic consequences. Conclusion: Obesity is not merely an issue of excess fat but a complex nutrition–health imbalance. Addressing it requires a paradigm shift from calorie reduction alone to improving diet quality, ensuring micronutrient adequacy, and implementing inclusive, stigma-free public health policies.