Researchers at the University of Leeds’ School of Food Science and Nutrition have uncovered a significant correlation between obesity in children and young people and the risk of iron deficiency. This extensive study reviewed thousands of medical studies from 44 countries that recorded iron levels alongside other essential vitamins and minerals in individuals under 25, comparing these levels with body weight. The study revealed that both underweight and overweight children and adolescents are prone to iron deficiency. However, deficiencies in zinc and vitamin A were exclusively noted in children suffering from undernutrition, suggesting that inflammation might be disrupting iron absorption mechanisms in obese children.
The research, supported by the UK Biotechnology and Biological Sciences Research Council and published in the ‘BMJ Global Health’ journal on 10 May 2024, highlighted the negative impact of iron deficiency on cognitive functions in children, affecting attention, concentration, and memory. These deficiencies are associated with an increased risk of developing conditions like autism and ADHD. This pioneering study is the first to explore the link between obesity and iron deficiency in children, a well-documented issue in adults but less understood in younger demographics.
Lead author Xiaomian Tan emphasized the significance of this hidden form of malnutrition, termed ‘hidden hunger,’ which is less noticeable than traditional forms of malnutrition. Hidden hunger has historically been associated with low- and middle-income countries where basic caloric needs are met, yet micronutrient needs are not, leading to significant health implications. However, this issue is increasingly prevalent in high-income countries, often due to diets high in ultra-processed, nutrient-poor, yet calorie-dense foods. Conversely, in poorer nations, obesity usually correlates with economic constraints that limit food variety, typically staple foods like corn, wheat, rice, and potatoes.
The global increase in obesity rates is contributing to a double burden of malnutrition and overnutrition, particularly among children aged between five and 19 years. The study notes significant regional disparities, with most research in Africa and Asia focusing on undernutrition, whereas studies from North America and Europe predominantly address overnutrition. Both continents are witnessing rising dual burdens of malnutrition, propelled by economic growth and shifts towards Western dietary habits. From 2000 to 2017, the number of overweight children under five years old in Africa rose from 6.6 million to 9.7 million, and in Asia, from 13.9 million to 17.5 million. Simultaneously, there was an increase in stunted growth among children under five in Africa, from 50.6 million to 58.7 million.
Professor Bernadette Moore, a research supervisor and professor of Nutritional Sciences, stressed the critical nature of these findings for child health. She highlighted that the issue is not just about iron deficiency but the broader implications of prolonged inflammation, which can lead to severe health conditions such as heart disease, diabetes, and fatty liver. The study underscores the urgent need for global attention to investigate micronutrient deficiencies and the double burden of malnutrition, emphasizing the importance of addressing this issue in the global health landscape.
The researchers advocate for increased physical activity and improved diets to combat inflammation and improve iron status in children. They are calling for further studies to evaluate the effectiveness of these interventions and to explore micronutrient deficiencies in the context of the double burden of malnutrition and overnutrition, especially in regions currently lacking comprehensive data. This call for further research aims to engage the audience, including healthcare practitioners, researchers, and policymakers, in the ongoing efforts to address this critical gap in the global health landscape.
More information: Xiaomian Tan et al, Overnutrition is a risk factor for iron, but not for zinc or vitamin A deficiency in children and young people: a systematic review and meta-analysis, BMJ Global Health. DOI: 10.1136/bmjgh-2024-015135
Journal information: BMJ Global Health Provided by University of Leeds
