Causes of Childhood Obesity
The causes of childhood obesity are complex and include genetic, biological, societal and behavioral factors. It is commonly understood that an imbalance between energy obtained from foods and energy expended in the BMR and physical activity results in obesity.
Genetic factors: A child with an obese parent is more likely to be obese as obesity tends to run in the family.
Dietary habits: Nowadays with multiple foods easily available, children hardly like to eat home food. The dietary habits have shifted from eating fruits, vegetables, whole grain preparation, milk and products to caloric dense (either loaded with fat or sugar) highly processed foods and drinks which just have calories and very less nutrition in proportion to the same.
The fat cell theory is one of the mechanisms that explain obesity in children due to overfeeding in early years of life. The fat cells are distributed throughout the body. The depot expands either by increasing the size of fat cell or by increasing their number. According to the theory the percentage of body fat is determined by the number of fat cells which is either influenced by genetic inheritance or eating habits.
The size of fat cells gradually increases if the energy balance is positive. If the energy or caloric intake continues to be high, cell number begins to increase. Once fat cells increase their number seems to be fixed and they cannot be lost even if weight is lost. In general, cells proliferate most rapidly from birth to 2 years of age and during the late childhood and puberty. If maximum fat cell size is attained by infants at one year of age and then additional fat is deposited by increasing the fat cell number, the chronically overfed child develops an excess number of fat cells.
This is different from obesity beginning in adulthood. In adulthood, obesity begins due to increase in the fat cell size.
During childhood, chronic overfeeding leads to increased number of these fat cells. Fat cells once formed cannot be decreased. In the long run if positive energy balance continues, fat cells would keep increasing in size further leading to obesity in adulthood as well. Thus, good eating habits during childhood are of great importance.
Eating habits: Eating while watching TV or when not hungry can lead to immense weight gain. Often eating out in various food joints is a major causative factor because of oversize portions and high grease content. The caloric content then is most often equivalent to a sum of two three meals at home. The food being highly fibre deprived gives no fullness. Apart from this the taste, hanging out with friends, celebrations, makes the child to emotionally overeat.
A study was done in Devangere city of Karnataka in two affluent school children in between 5th and 10th standard to know the prevalence of obesity and identify the factors influencing childhood obesity. The study concluded that consumption of high fat and high energy (junk foods) and snacking in between meals was the major reason for the children being obese. The experts stated that health education should be given to parents, teachers and children regarding dietary habits and sedentary lifestyles.
It was noted that 50 to 80 percent of obese children would continue as obese adults and fall into risk group of diabetes, hypertension, coronary heart disease and other obesity related diseases. They said that the complications of adult obesity worsen if the obesity begins in childhood.
Dr Anoop Mishra, Director, department of Diabetes and Metabolic Diseases, Fortis Hospital in a seminar organized in Delhi highlighted the alarming rise of childhood obesity, which he said in Delhi alone had increased from 16 percent in 2002 to 24 percent in 2007. He attributed the “multinational fast food giants as responsible for having pushed India to the threshold of childhood obesity and an entire generation of disease prone youth.
Physical inactivity: Modern lifestyles have become more comfortable and equally stressful. An increasing sedentary lifestyle with televisions, video games is taking away the children from outdoor sports. Children are habituated to the comfort provided to them which has reduced their activity levels drastically.
Medical factors: Certain medical conditions such as hormone imbalances and inherited disorders of metabolism can cause obesity.
Medications: Certain medications viz. steroids can cause weight gain by altering the body metabolism.
Stress: Stressful events in life like examinations, issues with friends, family problems can lead to erratic eating behavior.
- Lee WWR. An overview of pediatric obesity. Pediatric Diabetes. 2007; 8 (Suppl. 9)
- Kumud Khanna. Nutrition and Weight management In Textbook of Nutrition and Dietetics. New Delhi: India; 2001.
- Childhood overweight and obesity - (http://www.who.int/dietphysicalactivity/childhood/en/)
- American Obesity Association. Centers for Disease Control and Prevention. "Childhood Overweight".
- Kumar S, Mahabalaraju DK, Anoop MS. Prevelance of Obesity and its Influencing factor among Affluent School Children of Davangere City. Indian Journal of Community Medicine. 2007;32(1)
- Raj M, Sundaram, KR, Paul M, Deepa AS, Krishna Kumar, R. Obesity in Indian children: Time trends and relationship. The National Medical Journal of India. 2007;20(6)
- Singh M, Sharma M. Risk Factors for obesity in children. Indian Pediatrics. 2005; 42(17)