Childhood obesity facts
- Adult and childhood obesity has increased substantially in the last 30 years. Currently, 31% of adults and 18% of children at obese, as defined by excess body mass index (BMI).
- The vast majority of obesity represents an imbalance in calories ingested vs. calories expended. Other causes of obesity (metabolic, medicines, and other diseases) are very rare.
- Loosing body fat requires both caloric restriction and daily vigorous exercise.
- The immediate and long-term effects of obesity include physical, psychological, and economic issues.
- Obesity prevention will require both a personal and social/cultural change in lifestyle. A large volume of current research will help clarify what will be most helpful.
What is childhood obesity?
In order to systematically describe obesity, the concept of body mass index (BMI) was developed. BMI is the ratio between an individual's weight to height relative to their gender and age. BMI addresses the following question: Is the weight of the subject in excess of what is healthy for a given height? Generally (but not always), BMI correlates with the amount of body fat, but it is not a measurement of fat. An individual who has more than the average muscle mass for a given height (for example, weight lifters, some athletes) will have an elevated BMI but clearly will not be obese. Nomograms for both adults and children have been developed to graphically represent the range of normal when measuring BMI. An individual is overweight when their BMI is between 25.0-29.9. Obesity is defined as a BMI greater than 30.0. Many web sites have calculators to measure BMI (for example, http://www.cdc.gov/healthyweight/assessing/bmi/). Measuring body fat may be done via skin-fold-thickness measurement, waist-to-hip-circumference ratio and neutral buoyancy (water displacement) measurements. BMI is not used for children under 2 years of age.
How prevalent is childhood obesity?
The national statistics regarding childhood obesity prevalence (total number of cases in the pediatric population) have risen remarkably. In the 1970s and 1980s, approximately 5% of children were obese. By 2000, over 13% were obese, and 2009 statistics indicate pediatric obesity to be leveling off at approximately 18% of the population. (In contrast, approximately 31% of adults are obese.) While the frequency of obesity appears to be leveling off, the amount of excess weight has continued to rise (for example, BMI value has risen higher per individual).The Midwest and South have the highest frequency of obesity (28%), with Mississippi the highest frequency (34%) and Colorado the lowest (18%). Of the remaining states, 24 have an obese population of over 25%; nine states have over 30% of their population being obese. In 2000, no states had more than 30% of their population considered obese.
The Center for Disease Control and Prevention's web site (http://www.cdc.gov) has an excellent demonstration of the rise in obesity over the last 30 years by using an interactive map of the United States (http://www.cdc.gov/obesity/data/
trends.html#State).
An area of concern is that the statistics gathered in many studies are self-reported by the individual and may therefore be overly optimistic (for example, purposely underestimating weight and overestimating height).
What causes childhood obesity?
Most obesity is caused by excessive daily caloric intake relative to daily caloric expenditure. Excessive intake of calories is most commonly associated with poor food-quality choices (for example, fast food high in fat calories) but may also result from over-ingestion of "healthy foods." The simple biological fact is that all excessive calories (regardless whether triple cheese meat lovers pizza vs. fat free yogurt with berries) will be stored by the body and only as fat. Attempts at only reducing caloric intake without increasing caloric utilization (read: 30 minutes daily vigorous exercise) will only help temporarily. If calorie restriction is the sole approach toward losing weight, the body's metabolism adopts a conservation mode and learns how to get by on fewer calories. Adding physical activity to the calorie-burning equation encourages breakdown of excessive carbohydrate and fat stores allowing for more functional and long-term health.Body weight (not necessarily excessive body fatness) is a reflection of genes, metabolism, behaviors, culture, and socioeconomic status. These relatively infrequent causes of obesity will be detailed below.
What are childhood obesity symptoms and signs?
Measurement of height and weight are the most commonly used tools to quickly evaluate the proportionality of children. These measurements allow calculation of the body mass index (BMI). It is important to consider the physique of the individual. While having a weight in excess of what would be expected for a certain height is most commonly a documentation of excessive fat tissue, certain individuals may be overmuscled (for example, weight lifters). With the exception of very rare bone diseases, the idea of an individual's excessive weight due to being big boned is an urban myth.
