📊 What Is Low BMI in Children and Adolescents?
In children and adolescents, a Body Mass Index (BMI) below the 5th percentile for their age and sex is classified as underweight. This threshold is determined using age- and sex-specific BMI-for-age growth charts, such as those provided by the Centers for Disease Control and Prevention (CDC).
🌍 Global Prevalence and Public Health Significance
The World Health Organization (WHO) recognizes low BMI in children and adolescents aged 10–19 as a significant public health concern, particularly in low- and middle-income countries. Undernutrition during this critical period can lead to stunted growth, delayed maturation, impaired cognitive development, and increased susceptibility to infections. Globally, approximately 190 million children and adolescents aged 5–19 are affected by thinness, with a BMI-for-age more than two standard deviations below the median .
🧠 WHO Recommendations for Managing Low BMI in Adolescents
While WHO’s guidelines primarily address obesity, they provide valuable insights applicable to managing low BMI in adolescents:
- Comprehensive Lifestyle Interventions: Implement family-based, multicomponent lifestyle management services that include nutrition, physical activity, and psychosocial support. These services should be delivered by trained healthcare professionals as part of universal health coverage.
- Nutrition and Physical Activity: Encourage balanced diets rich in fruits, vegetables, whole grains, and healthy fats. Promote regular physical activity to support overall health, which can also stimulate appetite and support healthy weight gain.
- People-Centered Care: Adopt a primary healthcare approach that meets adolescents’ health needs throughout their lives, addresses broader determinants of health, and empowers individuals, families, and communities to take charge of their own health.
🌐 Global Efforts and Challenges
Efforts to combat undernutrition in adolescents are ongoing worldwide:
- Eastern Mediterranean Region: Some countries report alarmingly high rates of childhood overweight and obesity, indicating a need for balanced nutritional interventions.
- Seychelles Study: Research indicates varying prevalence rates of thinness among children and adolescents, highlighting the importance of context-specific interventions.
These examples underscore the necessity for tailored approaches that consider regional dietary habits, healthcare infrastructure, and socioeconomic factors.
🥗 Nutritional Strategies for Healthy Weight Gain
- Increase Caloric Intake with Nutrient-Dense Foods: Focus on providing calorie-rich, nutritious foods:
- Healthy Fats: Incorporate sources like olive oil, avocado, nuts, and nut butters.
- Protein-Rich Foods: Include lean meats, fish, eggs, dairy products, and legumes to support muscle development.
- Complex Carbohydrates: Offer whole grains such as brown rice, oats, and whole wheat pasta for sustained energy.
- Dairy Products: Provide full-fat milk, cheese, and yogurt to boost calorie intake.
Avoid relying on sugary or processed foods, as they may lead to unhealthy weight gain without providing essential nutrients.
- Regular, Balanced Meals and Snacks:
- Meal Frequency: Aim for three main meals with two to three healthy snacks daily.
- Snack Ideas: Offer options like cheese and whole-grain crackers, yogurt with fruit, or smoothies made with milk and nut butter.
- Hydration: Encourage drinking calorie-containing beverages like milkshakes or smoothies between meals.
- Monitor Growth and Seek Professional Guidance:
- Regular Monitoring: Keep track of weight and height to assess growth patterns.
- Professional Support: Consult with a pediatrician or dietitian to develop a tailored plan and address any underlying health concerns.
🏃 Importance of Physical Activity
While focusing on weight gain, it’s crucial to encourage physical activity to promote overall health:
- Strengthen Muscles and Bones: Activities like swimming, cycling, or resistance exercises can help build muscle mass.
- Enhance Appetite: Regular exercise can stimulate appetite, aiding in increased food intake.
- Mental Well-being: Physical activity supports mental health, reducing stress and anxiety.
Ensure that the chosen activities are enjoyable and age-appropriate to maintain motivation.
🧩 Addressing Underlying Causes
Identifying and managing any underlying medical or psychological factors is essential:
- Medical Conditions: Conditions like coeliac disease, hyperthyroidism, or gastrointestinal disorders can affect weight gain.
- Psychosocial Factors: Issues such as stress, trauma, or eating disorders may contribute to low BMI.
A multidisciplinary approach involving healthcare providers, mental health professionals, and dietitians can be beneficial.
🇱🇰 Cultural Considerations in Sri Lanka
In Sri Lanka, traditional dietary practices and food availability may influence nutritional intake:
- Local Foods: Incorporate local, calorie-dense foods like coconut milk, rice, lentils, and tropical fruits.
- Family Meals: Engage in communal eating practices to encourage social interaction and positive eating habits.
- Community Support: Leverage community resources and support systems to address nutritional challenges.
🩺 When to Seek Medical Advice
Consult a healthcare professional if:
- The child is not gaining weight despite dietary interventions.
- There are signs of underlying health issues, such as fatigue, digestive problems, or emotional distress.
- There is a significant decline in growth percentiles.
Early intervention can help prevent potential complications associated with low BMI.
By adopting a comprehensive approach that includes balanced nutrition, regular physical activity, and professional support, children and adolescents with low BMI can achieve healthy weight gain and overall well-being.
References
- Al Buairan, F.S., Hijji, T.M., & Saleheen, H. (2020). Underweight, body image and weight loss measures among adolescents in Saudi Arabia; Is it fad or is there more going on? International Journal of Paediatrics and Adolescent Medicine, 8(1), 18-24.
- Alton, I., & Luder, E. (2005). The underweight adolescents. ResearchGate.
- Creese, H., Hangreaves, D., Nicholls, H., Watt, C., & Whitfield, H. (2023). Risk factors of persistent adolescent thinness: Findings from the UK Millennium Cohort Study. BMC Public Health, 938.
- World Health Organization. (n.d.). A healthy lifestyle – WHO recommendations. Retrieved from https://www.who.int/europe/news-room/fact-sheets/item/a-healthy-lifestyle—who-recommendations/
Centers for Disease Control and Prevention. (2020). Prevalence of Underweight Among Children and Adolescents Aged 2–19 Years: United States, 1963–1965 Through 2017–2018. Retrieved from https://www.cdc.gov/nchs/data/hestat/underweight-child-17-18/underweight-child.htm
Sanduni Abeysinghe
MSc, BSc, PGDE
Registered Nutritionist
