Childhood obesity

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Iman Djarraya, BMedSci, MBChB, MPH[2]

Synonyms and keywords: Obesity in kids, obesity in children, childhood obesity, pediatric obesity

Overview

Childhood obesity is a Body Mass Index (BMI) at or above the 95th percentile for children of the same gender and age. It is a serious health problem that can result in health complications. Childhood obesity can be caused by lifestyle factors, underlying medical conditions, genetic causes or certain medications. It is important to differentiate obesity due to lifestyle factors from obesity due to medications or an underlying medical condition. Obesity in general may present with high blood pressure, insulin resistance, excess facial hair or irregular menstruation. The presence of polyuria and polydipsia suggests possible diabetes, excess facial hair, insulin resistance and irregular menstruation in adolescent girls may be due to polycystic ovary syndrome (PCOS) and dry skin, constipation and intolerance to cold suggest hypothyroidism. laboratory tests indicated depend on the clinical presentation. Management of obesity includes the treatment of any underlying medical conditions and lifestyle modification.

Historical Perspective

• Obesity was first recognized as a medical disorder by the ancient Greeks, in 450 B.C..

• In 550 B.C., obesity was linked to heart disease and diabetes by the Indian surgeon Shushruta.

Classification

• Child weight may be classified according to BMI-for-age growth chart into:

• Overweight BMI between 85th and 94th percentiles
• Obesity BMI 95th percentile or above
• Severe obesity 99th percentile or higher

Pathophysiology

• The pathogenesis of childhood obesity is characterized by energy imbalance
• This energy imbalance is the result of excess energy intake and/ or decreased energy expenditure.
• It has been suggested that a dysfunction in the ghrelin/leptin hormonal pathway may contribute to abnormal appetite control and increased energy intake.

Causes

Childhood obesity may be caused by poor eating habits, lack of physical activity, genetic causes, an underlying medical condition or medications.

Lifestyle and dietary intake

Children and adolescents are consuming low nutrient high-calorie foods and beverages at home, school and other places. They are consuming more fast food which is low in nutrients and high in calories, fat and sodium. CDC reports that children and adolescents in the U.S. consumed an average of 13.8% of their daily calories from fast food during 2015-2018. In addition, they are consuming large amounts of sugar-sweetened beverages which has been directly associated with obesity in multiple reviews. Physical inactivity, excess use of screen time and inadequate sleep also contribute to the obesity epidemic.

Environmental factors

Eating habits of the child are also affected by demographics, lunch policies at schools and work demands on parents.

Psychological factors

These factors influence a child's eating habits and many children eat in response to stress and or negative emotions such as boredom, anger, sadness, anxiety or depression.

Genetic factors

Often, a child whose parents are overweight or obese will also be overweight or obese. Although this is often caused by shared unhealthy eating habits in the household, it has been suggested that there may be a genetic (inherited) predisposition toward being obese, although this is as yet unproven and research is ongoing.

Medical conditions

There are genetic syndromes and hormonal disorders that may be associated with weight gain and obesity in children including: hypothyroidism, cushing syndrome, growth hormone deficiency, growth hormone resistance, leptin deficiency or resistance to leptin action, polycystic ovary syndrome (PCOS), precocious puberty, prolactin-secreting tumors, turner syndrome, down syndrome, cohen syndrome, prader-Willi syndrome, pseudohypoparthyroidism and laurence-moon-biedl syndrome.

Medications

Medications that may cause weight gain in children include cortisol and other glucocorticoids, tricyclic antidepressants, sulfonylureas, monoamine oxidase inhibitors, risperidone, clozapine, oral contraceptives, insulin (in excessive doses) and thiazolidinediones.

Hypothalamic obesity

Weight gain may occur after acquired hypothalamic lesions following surgery, cranial radiation or diencepahlic tumors. It can also be a result of cranial trauma or inflammation of the hypothalamus.

Complications

Without a change in diet or exercise patterns, childhood obesity can lead to medical conditions including Type 2 diabetes, high blood pressure, high cholesterol, heart disease, asthma, obstructive sleep apnea, fatty liver disease, gall stones, glucose intolerance, insulin resistance and other disorders. Studies have shown that obese children are more likely to grow up to be obese adults. Obese children often suffer from weight stigma, teasing and bullying amongst their peers. They experience descrimination in the society. These children are more likely to suffer from low self esteem, anxiety and depression.

Differentiating obesity due to lifestyle factors from other Diseases

• Childhood obesity due to lifestyle factors must be differentiated from other diseases that cause obesity, high blood pressure, and insulin resistance such as:

• Hypothyroidism
• Cushing syndrome
• diabetes
• polycystic ovary syndrome (PCOS)

Epidemiology and demographics

• The prevalence of children who are overweight or obese worldwide is approximately 38 million in children under the age of 5 in 2019 and more than 340 million between 5 and 19 years old in 2016.

• In 2015-2016, the prevalence of Childhood Obesity among children aged 2-19 years was estimated to be 13.7 million cases (18.5%) in USA.

Age

• Children of all age groups may develop Childhood Obesity.
• Childhood Obesity is more commonly observed among children aged 12 to 19 years old in the USA. This is followed by children aged 6 to 11 years old and then children aged 2 to 5 years of age.

Gender

• Childhood Obesity prevalence by gender is different depending on the region.
• Males are more commonly affected than females 5 to 19 years of age in most high and upper middle-income countries.

Race

• There are racial differences for obesity in children.

• Obesity prevalence was higher among Hispanics and non-Hispanic blacks than non-Hispanic whites and non-Hispanic Asians.

Risk Factors

• Common risk factors in the development of Childhood obesity are high calorie diet, lack of physical activity, children who have family members who are obese, stress and low-income households.

Natural History, Complications and Prognosis

• If left untreated, patients with childhood obesity may progress to develop type 2 diabetes, high blood pressure, high cholesterol, asthma, obstructive sleep apnea, non-alcoholic fatty liver, joint pain and depression.
• Common complications of childhood obesity include the progression to adult obesity and increased risk of heart disease, diabetes and cancer risk.

Diagnosis

History and Symptoms

• Symptoms of childhood obesity may include the following:

• hypertension
• irregular menstruation
• facial hair
• polyuria and polydipsia may suggest diabetes.
• dry skin, constipation, and intolerance to cold may suggest hypothyroidism.
• irregular periods, excess facial hair and acne may suggest polycystic ovarian syndrome or excess cortisol.

Physical Examination

• Physical examination may be remarkable for:

• dry skin and fatigability may be signs of hypothyroidism.
• purple striae and accumulation of fat in the neck and trunk may suggest cortisol excess.
• signs of early sexual development may be a sign of precocious puberty.
• acne and excess facial hair may suggest cortisol excess or polycystic ovary syndrome.

Laboratory Findings

• Children with BMI 85 or more require fasting blood glucose, fasting lipid panel, ALT, AST and serum hemoglobin A1C or 2-hour glucose tolerance test.
• The following tests may be indicated for children with obesity depending on the clinical presentation:

• Thyroid function tests
• Adrenal function tests
• Liver function tests
• Serum leptin
• Serum calcium, phosphorus and parathyroid hormone
• Growth hormone
• Reproductive hormones

Treatment

Medical therapy

• Management of obesity in children focuses on reducing BMI of the child safely, preventing and managing complications.
• The mainstay of therapy for obesity in children is diet and exercise.
• Setmelanotide, a melanocortin-4-receptor agonist was approved by the U.S. Food and Drug Administration (FDA) for children age 6 and older with obesity caused by rare genetic disorders.

Surgery

• Bariatric surgery are performed in some adolescents with severe obesity.

Prevention

• There are multiple preventive measures available for childhood obesity
• Effective measures for the primary prevention of childhood obesity include consumption of fruits and vegetables, drinking water, restriction of sweetened drinks and sugary snacks, regular physical activity, limiting screen time, reducing stress, and providing a healthy sleep routine.

See also

• Hereditary factors in childhood obesity

External links

• Common Sense Media Resources
• Commercial Alert's web page on childhood obesity
• Study of Breakfast Eating and Income Levels in Preschoolers
• Mindless eating Cornell University Food and Brand Lab [3]
• Mayo clinic article on preventing childhood obesity
• March, Peter. "Fattened statistics". Social Issues Research Center. Retrieved 2007-04-21.
• Summerfield, Liane M. "Childhood Obesity". Education Resources Information Center Clearinghouse on Teacher Education, Washington, DC. Retrieved 2007-08-04.