Obesity, or simple obesity (obesity), refers to an excessive accumulation of subcutaneous fat in the abdominal area. It is generally considered obesity when body weight exceeds the average standard weight for height by 20%, or exceeds the average standard weight for age plus two standard deviations (SD). Obesity can be classified into mild, moderate, and severe grades based on the extent of excess weight. Grade I obesity is defined as exceeding the standard weight by two to four standard deviations, Grade II as exceeding by three to four standard deviations, and Grade III as exceeding by more than four standard deviations.

bubble_chart Etiology

1. The primary cause of obesity is overeating, where the intake of calories exceeds the amount expended, leading to the conversion of excess calories into abdominal mass fat stored in the body. Children of obese parents often exhibit the same tendency. Members of a family frequently develop a habit of consuming rich foods. If a child develops the habit of overeating from an early age, obesity may manifest over time.

2. Excessive rest and lack of exercise—Insufficient physical activity and exercise are also significant factors in obesity. Overweight children often dislike physical activity. Among the cases of childhood obesity we observed, the vast majority were cases of simple obesity characterized by low activity and excessive eating. During the stage of convalescence from hepatitis or other illnesses, excessive rest and insufficient exercise often lead to gradual weight gain. The heavier they become, the less they move, creating a vicious cycle.

3. Genetic factors—Parents of obese children are often overweight themselves. If both parents are significantly above normal weight, approximately two-thirds of their offspring may develop obesity. If only one parent is obese, the likelihood of the child becoming obese is about 40%.

4. Neuropsychiatric disorders—Obesity may occasionally occur after encephalitis. Hypothalamic disorders or frontal lobe resection can also lead to obesity. Children who experience emotional trauma (such as the death of a loved one or poor academic performance) or psychological abnormalities may sometimes develop obesity as well.

Grade III obesity is more common in older children and adolescents and relatively rare during infancy and early childhood. These children typically have an exceptionally strong appetite, consuming more food than average, with a preference for starchy and fatty foods and a dislike for vegetables. Some children may exhibit a smaller appetite at the time of medical consultation, but they must have gone through a phase of excessive eating before the onset of obesity. Fat accumulation in these children is most noticeable in the breasts, abdomen, hips, and shoulders. The abdomen often shows faint pink skin striae, and the limbs are enlarged, particularly the upper arms and thighs. In boys, the external genitalia may appear small due to being obscured by pubic fat, but they are actually within the normal range. Bone age is normal or advanced compared to peers. Intelligence is normal, and sexual development is either on time or slightly early. Physical activity is limited, and exercise is minimal.

In rare cases, extremely obese children may weigh 4 to 5 times the standard weight. Excessive fat can restrict the movement of the chest wall and diaphragm, leading to shallow, rapid breathing, reduced alveolar ventilation, and resulting in hypoxemia. This may be complicated by polycythemia, cyanosis, cardiomegaly, and congestive heart failure, a condition known as Pickwickian syndrome, which can be fatal.

bubble_chart Auxiliary Examination

1. Serum triglycerides, cholesterol, low-density lipoprotein, very low-density lipoprotein, and apolipoprotein B are mostly significantly elevated, while high-density lipoprotein and apolipoprotein A₁ are normal.

2. Serum insulin levels are increased, and blood insulin concentration can return to normal after weight loss in children.

3. The secretion rate of adrenal cortex hormones increases, but the catabolism of corticosteroids in peripheral tissues also accelerates. Therefore, the total plasma cortisol concentration is mostly normal, but the metabolic products in urine increase, and urinary 17-hydroxycorticosteroids are often significantly elevated.

4. Dexamethasone suppression screening test: Cortisol secretion in children can be significantly suppressed.

Clinical Manifestations

(1) The disease peaks in infancy, preschool age, and adolescence.

(2) The children exhibit excessive appetite, large food intake, preference for sweet and fatty foods, and reluctance to engage in physical activity.

(3) Externally, they appear tall and obese, with not only weight exceeding that of their peers but also height and bone age at or above the upper limits for their age group, sometimes even surpassing them.

(4) Subcutaneous fat is evenly distributed, with significant accumulation in the cheeks, shoulders, chest, and abdominal wall. The limbs, particularly the thighs and upper arms, are thick, while the extremities are relatively slender.

(5) In boys, fat accumulation in the perineal area may bury the penis, leading to a mistaken impression of underdeveloped external genitalia. Sexual development is mostly normal in these children, and their intelligence is good.

(6) Severe obesity may lead to obesity hypoventilation syndrome.

2. Diagnostic Criteria Those whose weight exceeds the standard weight for their height by 20–30% are classified as grade I obesity, by 30–50% as grade II obesity, and by more than 50% as grade III obesity.

bubble_chart Treatment Measures

1. Dietary Management The primary approach to treating fatty disease caused by any reason is dietary management. The principles of dietary adjustment are as follows.

(1) When restricting food intake, it is essential to meet the basic nutritional and developmental needs of the child, ensuring only a gradual reduction in body weight. Initially, the goal is merely to halt rapid weight gain. Later, weight can be gradually reduced until it exceeds the normal range by about 10%, at which point further dietary restrictions are unnecessary.

(2) Efforts should be made to satisfy the child's appetite and avoid hunger. Therefore, foods with low caloric content but large volume should be selected, such as wild celery herb, bamboo shoots, and radishes. If necessary, low-calorie snacks like sugar-free jelly, dried fish, or preserved plums can be provided between meals.

(3) Protein-rich foods can satisfy appetite, have a higher specific dynamic effect, and are essential for growth and development. Thus, the daily supply should not be less than 2g/kg.

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(5) Fats provide excessive energy and should be restricted. Fried foods, rich oily dishes, and various sweet fatty foods are strictly prohibited.

(6) Total caloric intake must be reduced. For obese children aged 10–14, the general caloric supply should be around 5020 joules (1200 calories), with adjustments made based on individual circumstances.

(7) Vitamins and minerals must be adequately supplied. Regular exposure to sunlight is often necessary.

(8) Based on the above principles, the diet should primarily consist of vegetables, fruits, wheat-based foods, and rice, supplemented with moderate amounts of protein-rich foods such as lean meat, fish, eggs, beans, and their products. Successful dietary management requires long-term cooperation from both parents and the child, with frequent encouragement to adhere to the treatment for satisfactory results.

2. Alleviating Psychological Burden Some parents excessively worry about their obese child, seeking medical help everywhere, while others criticize or overly interfere with the child's eating habits, leading to stress or resistance. Such behaviors should be avoided. For children with emotional trauma or psychological issues, repeated counseling and active support are needed to alleviate their worries and depression. The child should be encouraged to build confidence and change overeating and sedentary habits.

3. Increasing Physical Exercise The child's interest in exercise should be fostered, making it a daily habit. Activities should be varied, including jogging, calisthenics, tai chi, table tennis, and Grade I swimming. Family members of the obese child are encouraged to participate to enhance effectiveness. Daily exercise should last about one hour and be gradually increased. Intense exercise, which may stimulate appetite, should be avoided.

4. Occasional Drug Therapy Medication is generally not encouraged for adolescents. Occasionally, amphetamine may be used to reduce appetite, typically in small doses of 2.5–5mg taken orally half an hour before meals, twice daily, for a short course of 6–8 weeks.

5. Treatment of Comorbid Hypoxemia For complications such as shortness of breath, hypoxemia, and heart failure, a low-calorie diet of about 3347 joules (800 calories) should be provided, along with cardiac stimulants, diuretics, and low-concentration oxygen therapy for emergency care. Excessive oxygen should be avoided to prevent respiratory suppression. Anticoagulant therapy may help prevent thrombosis.

bubble_chart Prognosis

Simple obesity in children can easily lead to complications such as flat feet and inversion. If it persists and progresses, it may result in conditions like arteriosclerosis, hypertension, coronary heart disease, and fatty liver in adulthood.

bubble_chart Prevention

Children with excessive obesity not only experience abnormal daily life but may also develop cardiopulmonary insufficiency. In adulthood, they are more prone to complications such as hypertension, coronary heart disease, and diabetes. Therefore, prevention of obesity should be addressed from an early age. During the late stage of pregnancy (third trimester), mothers should avoid excessive weight gain to prevent the birth of macrosomic newborns with high birth weight. After birth, breastfeeding should be maintained, and semi-solid or solid starchy foods should not be introduced before 4–5 months. During infancy and early childhood, regular growth and development monitoring should be conducted at pediatric clinics to detect early signs of overweight or obesity tendencies and correct them promptly. Cultivating healthy eating habits from a young age and maintaining a balanced diet are essential. For overweight children, food intake should be restricted to bring their weight closer to the standard range. During childhood and adolescence, particularly puberty, the risk of obesity increases. If there is a family history of obesity or rapid weight gain, early dietary guidance should be reinforced. The diet should follow the principles of low sugar, low fat, adequate protein, and increased consumption of fruits and vegetables, with particular emphasis on reducing sugary drinks and desserts. At the same time, physical activity should be increased by engaging in household chores and maintaining 1–2 sports activities consistently to achieve results. Regular weight monitoring is also necessary to prevent obesity. Parents who are obese should participate in dietary therapy and share meals with their children, which can have a positive impact.

bubble_chart Differentiation

Simple obesity in children often results in the external genitalia being concealed by excessive body fat, leading to a mistaken impression of delayed genital development, which should be noted. Overweight children are commonly suspected to have endocrine abnormalities, but in reality, obesity caused by endocrine system disorders is relatively rare and is usually accompanied by other symptoms for differentiation.

Pituitary and hypothalamic disorders can cause obesity, known as adiposogenital dystrophy, but the body fat has a distinctive distribution, being most prominent in the neck, submental area, breasts, hips, and upper thighs, with tapering fingers. It is also associated with intracranial lesions and delayed gonadal development. Diencephalic damage due to head trauma can also lead to general obesity, but it is accompanied by diabetes insipidus, hypogonadism, and other autonomic nervous system symptoms.

In hypothyroidism, the abdominal mass of body fat is mainly concentrated in the face and neck, often accompanied by myxedema, significantly stunted growth, and low basal metabolic rate and appetite.

Adrenal cortical tumors and long-term use of adrenal corticosteroids can cause Cushing's syndrome, characterized by excessive fat accumulation in the cheeks and submental area, forming a distinctive facial appearance, along with thicker fat deposits on the chest and back. It is often accompanied by hypertension, reddish-purple skin, increased body hair, and precocious genital development. A mass may sometimes be palpable in the abdomen, and abdominal X-rays may reveal calcified shadows. Some diabetic children and those with ovarian dysfunction, such as Stein-Leventhal syndrome, may also exhibit obesity.

Glycogen storage disease in the liver can cause a plump facial appearance, with particularly severe fat accumulation in the lower abdomen and pubic region. Prader-Willi syndrome is another congenital metabolic disorder, with obesity beginning in the advanced infant stage, accompanied by hypotonia, short stature, small hands and feet, intellectual disability, gonadal dysgenesis, strabismus, and often developing diabetes by adolescence. Laurence-Moon-Biedl syndrome is a multiple malformation disorder, including digit deformities, obesity, visual impairment, and intellectual disability.