Obesity in Adolescents and Children

Boy (7-9) smiling while looking down at slice of pepperoni pizza
Boy (7-9) smiling while looking down at slice of pepperoni pizza

The increasing occurrence of Obesity amongst the young is a matter of concern, and especially so because obesity in childhood can lead to problems like diabetes in adulthood, notes Dr Manu Raj, who has national and international expertise in the field of research in obesity and pediatric cardiology.


Childhood obesity is a global phenomenon affecting all socio-economic groups, irrespective of age, gender or race. Childhood obesity is caused by several factors including biological, psychological, environmental and socio-cultural issues. Many diseases like Diabetes, high cholesterol, liver disease, lung disease and other problems are increasingly seen in association with childhood obesity. The treatment of overweight and obese children and adolescents requires a multidisciplinary, multi-phase approach which includes dietary management, physical activity enhancement and restriction of sedentary behavior. Additionally, drug therapy and surgery may be required in a minority of obese youngsters.

Definition of childhood obesity

Overweight and obesity among children and adolescents are defined using age and sex specific reference charts for Body Mass Index (BMI). Children whose body mass index that exceeds the age-gender-specific 95th percentile are defined obese. Those children and adolescents whose BMI is between the 85th and 95th percentiles are defined as overweight.

Note:A percentile score tells us the percentage of other scores lesser than the data point we are investigating. They clarify the interpretation of scores on standardized tests. For example: You are the fifth tallest person in a group of 10. 50% of people are shorter than you. That means you are at the 50th percentile.

Weight Status CategoryPercentile RangeUnderweightLess than the 5th percentileHealthy weight5th percentile to less than the 85th percentile Overweight 85th to less than the 95th percentile Obese Equal to or greater than the 95th percentile

Risk factors for the development of childhood/adolescent obesity

Several risk factors are known to be related to obesity in children and adolescents. These are other family members with obesity, dietary patterns, physical activity patterns, psychological factors, socioeconomic factors and family food purchase practices. If the child comes from a family of overweight people, he or she may be more likely to be overweight or obese. The risk is higher if the child is bought up in an environment where high-calorie food is always available and physical activity isn't encouraged.

  • Poor diet

Dietary patterns are the major contributors to obesity in the young. Any child/adolescent who consumes more calories than what is required for growth and activity will put on excess weight and in due course will cross the BMI threshold to become obese. These excess calories may be as small as 100 Kcal per day but will add up and be in the range of several thousands of Kilo Calories per year and result in excess weight gain of several Kg per year. As years pass by, the adolescent will easily be having weight in excess of 10 to 50 Kg compared to his/her ideal weight. Most of the excess calories are usually from snacks, desserts and sugary drinks (at school and at home) that are rich in calories, sugar, saturated fat and salt which by themselves add more harm in addition to increasing weight. These harms are increased rates of high blood pressure, bad cholesterol levels and diabetes.

  • Lack of exercise

Physical activity among children and adolescents have shown a decreasing trend over the last several decades thanks to technological advances like efficient, easily available transport facilities, TV, computers and video games. In addition, the lacks of adequate playgrounds coupled with unsafe pavements/streets along with poorly planned urban living communities have discouraged children from proper physical activities. Moreover parents have become more and more reluctant to let children play outdoors due to safety reasons, out of school academic engagements and ignorance of the benefits of proper physical activity. This is despite the fact that children who have regular exercise have reduced blood pressure, lower levels of bad cholesterol, lower levels of obesity and lower risk of future cardiovascular diseases as proven by thousands of research studies in the recent times. Children and adolescents who exercise regularly during youth will live at least a decade longer than their non-exercising counterparts in addition to evading obesity and related complications.

  • Stress

Increasingly, children and adolescents resort to overeating as a response to psychological stress as well as to tackle boredom from staying indoors.

  • Unhealthy lifestyle choices

Family purchase patterns like a preference for packaged/processed food items and precooked food portions usually add to excess calorie consumption of the entire family. Skipping cooking at home also promotes eating out by children and their options often are junk food/fast food outlets. Children from low socioeconomic sections may have limited access to good quality outdoor activities and healthy food options.

Media also plays a role in childhood obesity by promoting advertisements of fast food items and sugary drinks targeted at children and adolescents. Children and adolescents who watch TV and/or play computer/video games more than two hours per day are at high risk for obesity. Watching TV during mealtime increases food consumption by the child/adolescent and results in excess weight gain.

Complications related to childhood obesity

Children and adolescents who are obese/overweight can have complications related to physical, social and emotional well-being.

  • Physical complications

The major physical complications include metabolic syndrome, Type 2 Diabetes, high cholesterol levels, high blood pressure, asthma, sleep disorders and menstrual abnormalities. Metabolic syndrome is a cluster of conditions (high blood pressure, high blood sugar, high cholesterol and excess abdominal fat) that can put the child/adolescent at risk of cardiovascular diseases, diabetes or other chronic illnesses in future. Type 2 Diabetes is a condition where glucose metabolism is impaired in the body and is often promoted by excess weight and a sedentary lifestyle.

Childhood obesity can result in raised blood pressure and raised bad cholesterol levels. Both these conditions can promote fatty lesions called plaques in the inside of arteries especially that of the heart and brain. These plaques can cause arteries to narrow and harden, which may lead to a heart attack or stroke while they reach adulthood.

Excess weight can result in worsening of asthma and also result in other breathing problems. Children and adolescents with obesity may have sleep disordered breathing called obstructive sleep apnea. This disorder can reduce the oxygenation of brain during sleep and make the child/adolescent tired and confused during daytime. This disorder can result in poor scholastic performance at school and can also increase blood pressure.

Girl children/adolescents with obesity can have several menstrual abnormalities (early menstruation, irregular menstruation or cessation of menstruation and polycystic ovarian disease). These issues may affect their future growth as well as reproductive health.

  • Social and emotional complications

Social and emotional complications that are related to childhood/adolescent obesity include low self-esteem, bullying, behavioral issues, learning problems and depression. Obese children/adolescents are often bullied during school/college life and have higher chance of depression compared to their non-obese peers. The risk of depression is higher if they are victims of bullying. The scholastic performances of obese subjects are lower on an average compared to non-obese subjects.

Diagnostic evaluation

All children and adolescents who are found to be obese or overweight require a detailed evaluation that includes a proper history, physical examination and selected blood tests. The history will identify the risk factors that may have contributed to the child's/adolescent's excess weight gain.

A physical examination may reveal acanthosis nigricans (darkening of the back of the neck, axilla, and knuckles) which suggests insulin resistance. A blood pressure measurement will reveal subjects with high blood pressure. Many times, parents are worried that their child has a hormonal problem- however it is rare for hormonal problems to present with obesity. If the child is growing tall, the obesity is usually related to a sedentary lifestyle. However, wherever the child is obese but of short height, the doctor usually evaluates for a hormonal cause like thyroid gland failure. A blood test is required to check fasting glucose levels, insulin, total, LDL & HDL cholesterol levels, triglyceride levels and liver enzymes. An optional thyroid hormone assessment is required for some subjects. Some subjects may also require selected endocrinological assessments.

Treatment of childhood/adolescent obesity

The treatment of overweight and obesity in children and adolescents requires a multidisciplinary approach and include a pediatric physician, nurse practitioner, dietician, physical instructor, behavioral therapist and a social worker in addition to a motivated team of parents, caretakers, teachers and policy makers.

The components of overweight and obesity treatment include dietary management, physical activity enhancement, restriction of sedentary behavior, pharmacotherapy and bariatric surgery.

Dietary management

Dietary management should aim at weight maintenance or weight loss without compromising appropriate calorie intake and normal nutrition.

AgeCalorieProteinFat1-0 years1240- 2190 kcal/day20-40 g/day25 g approx. (5 teaspoons of total oil intake)11-18 years2000 kcal/day50-75 g/day20 g approx. (4 teaspoons of total oil intake)

Source: Nutritive Value of Indian Foods, NIN, 2012

  • Ideally fat intake in children 1 to 3 years old should be between 30% to 40% kcal of the total daily calorie intake and in 4 to 18 years olds should be between 25% to 35% kcal of the total daily calorie intake.

  • Carbohydrate intake should be between 45% to 65% kcal of the total daily calorie intake.

  • Protein intake should be between 5% to 20% kcal of the total daily calorie intake in children 1 to 3 years old with gradual increase to 10% to 30% kcal of the total daily calorie intake in children 4 to 18 years old.

  • Saturated fats should be providing 10% or less of the total calories.

  • The remaining 10-20% energy intake should be from mono and poly saturated fats. The total cholesterol intake should be less than 300 mg per day.


Fats are nutrients that give you energy and help your body absorb vitamins. Carbohydrates are one of the main types of nutrients which constitute the most important source of energy for your body. Proteins are the building blocks of life. They help your body repair cells and make new ones and are important for growth and development in children, teens, and pregnant women. Saturated fat can raise blood cholesterol and can put you at risk for heart disease and stroke. Their intake must be avoided or limited. Polyunsaturated and monounsaturated fat are both unsaturated fats. "Poly" means many unsaturated chemical bonds and "mono" means one unsaturated chemical bond. They are found in liquid vegetable oils. Cholesterol is a waxy, fat-like substance that occurs naturally in all parts of the body and helps your body to work properly.

Age-appropriate serving sizes including five or more servings of fruit and vegetables, three or more servings of low fat milk or dairy products, and six or more servings of whole-grain and grain products per day as well as adequate amounts of dietary fiber (age in years + 5 g/d) should also be encouraged. Due emphasis should be given to reduction in eating out and planning for healthy snacks at school and at home.

Physical activity enhancement

Adequate physical fitness in obese children/adolescents requires regular (at least four times per week) participation in physical activities that result in moderate to vigorous exertion (50-60% or more of age appropriate maximal exertion). These episodes of physical activity should be 45 minutes or more in duration and should accumulate not less than three hours per week. Longer durations are associated with better reductions in body weight. Activities can be a combination of recreational and organized or competitive sporting activities.

Note: Regular exercise can help children reduce and even reverse the risk of developing heart disease and Diabetes.

Screen time should be limited to less than two hours per day if possible. Longer periods of moderate intensity exercises like brisk walking and cycling burn more fat as calories and are excellent for reducing body fat. Children should be prescribed physical activity that is safe, developmentally appropriate, interesting, practical and has a social element. Involving other members of the family in the exercise program improves the results dramatically.

Note: In recent years, there has been significant work in integrating physical activity into video games. This has been done with the aim to motivate sedentary people to be more physically active. Nintendo's Wii Sports for example has successfully shown that exercise games can be both fun and at the same time induce obese children to exercise in an urban setting. Playing realistic sports video games can also lead to an increased time spent playing sports and exercising in real life. Learning new moves from sports video games may encourage obese children to practicing them or take up a new sport.

Drug therapy & surgical management

The utility of pharmacological therapy for pediatric obesity is limited. These drugs should only be used under the supervision of a pediatric/endocrine specialist due to the resultant side effects. Some cases of severe adolescent obesity deserve aggressive approaches including surgical treatment. Adolescent candidates for bariatric surgery should be very severely obese (defined by body mass index of >40), have attained a majority of skeletal maturity (generally >13 years of age for girls and >15 years of age for boys), and have comorbidities related to obesity that might be remedied with durable weight loss. The bariatric procedures preferred in adolescents are sleeve gastrectomy, Roux-en-Y gastric bypass and adjustable gastric banding.

The surgical options are also associated with significant side effects. These needs to be carefully selected weighing the merits and demerits. These are almost never advised in routine pediatric practice, owing to limited scientific data, and completion of sexual maturation is important if these procedures are even considered as possibilities. Basically, diet and exercise are the most important tools.

A prevention oriented approach

The ideal preventive strategy for obesity is to prevent children with a normal, desirable BMI from becoming overweight or obese. Preventive strategies should start as early as newborn period. The strategies may be attempted at the individual, community or physician's level.

It has been showed that proper breastfeeding may prevent obesity. All babies should be exclusively breast fed for the first six months. Breast feeding should be continued while solids are introduced to the infant's diet. Added sugar in infant food items should be avoided. Growth monitoring should be done for all children with the help of a physician and nutrition should be based on the child's BMI status. Schools should have annual growth monitoring programs under the supervision of a pediatrician.

All children and adolescents should be encouraged to play outdoors at least for a minimum of one hour on school days and two hours or more on other days. Children and adolescents should be provided options for training if they show interests in competitive sports. Outdoor exercises with parental involvement can be tried on weekends. Regular exercises by parents encourage children to be physically active. All children and adolescents should be provided safe and accessible playgrounds in the neighborhood.

Good eating habits should be introduced even during infancy. Healthy eating should be practiced by the family as a whole. There should be constant availability of fruits and fresh vegetables in the dining room. Fast food items and sugar rich drinks should be restricted to minimum. Eating outs should be carefully planned. Portion sizes for children and adolescents should be appropriate for their age. Healthy eating habits of parents encourage children to adopt the same.

TV viewing, computer/video games and other sedentary activities should be kept at minimum (two hours or less per day) while the child/adolescent is at home. This practice needs to be extended to the whole family.

Parents and children should be aware of ideal weight for various ages and the issues related to excess weight gain. Awareness classes can be attempted at school and in the neighborhoods. Schools should have longer exercise hours and healthy canteens that avoid junk food and provide healthy alternatives as snacks and drinks. They should also take an active role in promoting physical activity and healthy eating by children. Local administrative agencies should actively involve in making communities healthy and active by providing them with options like farmers markets for fresh produce, playgrounds for outdoor activities and safe pavements for walking, cycling and other activities.

To conclude

The epidemic of childhood/adolescent obesity is one among the major concerns for pediatric healthcare providers, parents and policy makers currently. These concerns are based on scientific evidence related to complications of excess weight gain during childhood and adolescence. This epidemic can be tackled only by a multidisciplinary approach that involves all stake holders. Our children deserve a better future and we need to work as a team to keep them healthy and active. Avoiding obesity during childhood and adolescence is one big step to a better future for our young population.

Dr Manu Raj is a Public Health Expert, a Paediatrician and a Faculty member at the Amrita Institute of Medical Sciences, Cochin- where he researches the increasing occurrence of obesity and cardio-metabolic health among children and adolescents. He has worked in the field of paediatric cardiology and epidemiology in India and in Canada.

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