Obesity in Children

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | References

Definition

Obesity in children is defined as excessive body fat that negatively affects a child's health. It is often diagnosed based on Body Mass Index (BMI) percentiles. Children with a BMI at or above the 95th percentile for their age and gender are classified as obese, while those between the 85th and 94th percentiles are considered overweight. Obesity in childhood significantly increases the risk of developing various chronic diseases later in life, including type 2 diabetes, cardiovascular disease, and musculoskeletal issues.

Aetiology

Obesity in children is a result of an imbalance between energy intake and expenditure. Several factors can contribute to this imbalance, including:

• Poor dietary habits: High intake of calorie-dense foods, sugary drinks, and fast food.
• Lack of physical activity: Sedentary behaviour such as excessive screen time and lack of outdoor play.
• Genetic factors: A family history of obesity can predispose children to being overweight.
• Socioeconomic factors: Limited access to healthy foods, living in unsafe neighbourhoods, or financial constraints can contribute to obesity.
• Psychosocial factors: Emotional eating due to stress, anxiety, or family issues can lead to overeating.
• Medical conditions: Rarely, obesity in children may be due to underlying medical conditions such as hypothyroidism, Cushing's syndrome, or Prader-Willi syndrome.

Pathophysiology

Obesity occurs when there is a sustained positive energy balance, meaning that calorie intake consistently exceeds calorie expenditure. Excess energy is stored as fat in adipose tissue, leading to weight gain. Over time, increased fat mass can lead to insulin resistance, metabolic syndrome, and a higher risk of type 2 diabetes. Obesity also affects hormonal regulation, increasing levels of leptin (which regulates appetite) and decreasing insulin sensitivity, further promoting fat storage and weight gain. Additionally, inflammation from excess adipose tissue can lead to cardiovascular and other systemic complications.

Risk Factors

• Family history of obesity or related metabolic conditions.
• Low levels of physical activity and sedentary lifestyle.
• Diet high in processed foods, sugary beverages, and fast food.
• Low socioeconomic status, impacting access to healthy food and physical activity opportunities.
• Poor sleep patterns, including sleep deprivation or sleep apnoea.
• Psychological factors such as emotional stress, depression, or anxiety.
• Medical conditions such as hypothyroidism, growth hormone deficiency, or Cushing's syndrome.

Signs and Symptoms

Children with obesity may present with the following:

• Increased body fat, especially around the abdomen.
• Shortness of breath or difficulty with physical activities.
• Joint pain, particularly in the knees and lower back.
• Fatigue or lethargy.
• Increased sweating and heat intolerance.
• Psychological issues such as low self-esteem, social isolation, or bullying.
• Signs of insulin resistance, such as acanthosis nigricans (dark, velvety skin patches, often around the neck).

Investigations

Investigations for childhood obesity focus on assessing the extent of the condition and identifying any complications:

• Body Mass Index (BMI): BMI is used to determine if the child is overweight or obese based on age- and sex-specific percentiles.
• Blood tests:
  • Fasting blood glucose: To assess for insulin resistance or diabetes.
  • Lipid profile: To check for dyslipidaemia (high cholesterol or triglycerides).
  • Liver function tests: To screen for non-alcoholic fatty liver disease (NAFLD).
  • Thyroid function tests: To rule out hypothyroidism as a contributing factor.
• Blood pressure measurement: To check for hypertension, which is common in obese children.

Management

The management of childhood obesity focuses on lifestyle modifications to achieve gradual weight loss and improve overall health. Treatment often involves the child, family, and multidisciplinary support.

Lifestyle Modifications:

• Dietary changes: Promote a healthy, balanced diet rich in fruits, vegetables, whole grains, and lean proteins. Limit intake of processed foods, sugary drinks, and high-fat snacks.
• Physical activity: Encourage at least 60 minutes of moderate to vigorous physical activity daily. This can include walking, cycling, swimming, or organised sports.
• Reduce sedentary behaviour: Limit screen time (television, video games, computers) to less than two hours per day.

Behavioural Interventions:

• Family-based behavioural therapy to encourage healthy eating and physical activity for the entire household.
• Counselling or psychological support for children who are experiencing emotional issues related to obesity, such as low self-esteem or bullying.

Medical Management:

• Metformin: In some cases of insulin resistance or pre-diabetes, metformin may be prescribed to improve insulin sensitivity.
• Referral to a paediatric endocrinologist: If underlying medical conditions such as hypothyroidism or Cushing's syndrome are suspected.

Follow-up and Monitoring:

• Regular monitoring of BMI, blood pressure, and blood glucose levels to assess progress and prevent complications.
• Referral to a dietitian for personalised meal planning and ongoing support.

References

1. NHS (2024). Childhood Obesity: Diagnosis and Management. Available at: NHS
2. NICE (2024). Obesity: Identification, Assessment and Management in Children. Available at: NICE Guidance
3. British Medical Journal (2023). Paediatric Obesity: Clinical Guidelines. Available at: BMJ