IMPORTANCE Despite concern about an “epidemic,” there are limited data on trends in prevalence of either type 1 or type 2 diabetes across US race and ethnic groups. OBJECTIVE To estimate changes in the prevalence of type 1 and type 2 diabetes in US youth, by sex, age, and race/ethnicity between 2001 and 2009. DESIGN, SETTING, AND PARTICIPANTS Case patients were ascertained in 4 geographic areas and 1 managed health care plan. The study population was determined by the 2001 and 2009 bridged-race intercensal population estimates for geographic sites and membership counts for the health plan. MAIN OUTCOMES AND MEASURES Prevalence (per 1000) of physician-diagnosed type 1 diabetes in youth aged 0 through 19 years and type 2 diabetes in youth aged 10 through 19 years. RESULTS In 2001, 4958 of 3.3 million youth were diagnosed with type 1 diabetes for a prevalence of 1.48 per 1000 (95% CI, 1.44–1.52). In 2009, 6666 of 3.4 million youth were diagnosed with type 1 diabetes for a prevalence of 1.93 per 1000 (95% CI, 1.88–1.97). In 2009, the highest prevalence of type 1 diabetes was 2.55 per 1000 among white youth (95% CI, 2.48–2.62) and the lowest was 0.35 per 1000 in American Indian youth (95% CI, 0.26–0.47) and type 1 diabetes increased between 2001 and 2009 in all sex, age, and race/ethnic subgroups except for those with the lowest prevalence (age 0–4 years and American Indians). Adjusted for completeness of ascertainment, there was a 21.1% (95% CI, 15.6%–27.0%) increase in type 1 diabetes over 8 years. In 2001, 588 of 1.7 million youth were diagnosed with type 2 diabetes for a prevalence of 0.34 per 1000 (95% CI, 0.31–0.37). In 2009, 819 of 1.8 million were diagnosed with type 2 diabetes for a prevalence of 0.46 per 1000 (95% CI, 0.43–0.49). In 2009, the prevalence of type 2 diabetes was 1.20 per 1000 among American Indian youth (95% CI, 0.96–1.51); 1.06 per 1000 among black youth (95% CI, 0.93–1.22); 0.79 per 1000 among Hispanic youth (95% CI, 0.70–0.88); and 0.17 per 1000 among white youth (95% CI, 0.15–0.20). Significant increases occurred between 2001 and 2009 in both sexes, all age-groups, and in white, Hispanic, and black youth, with no significant changes for Asian Pacific Islanders and American Indians. Adjusted for completeness of ascertainment, there was a 30.5% (95% CI, 17.3%–45.1%) overall increase in type 2 diabetes. CONCLUSIONS AND RELEVANCE Between 2001 and 2009 in 5 areas of the United States, the prevalence of both type 1 and type 2 diabetes among children and adolescents increased. Further studies are required to determine the causes of these increases.

WHR and WC are significantly associated with the risk of incident CVD events. These simple measures of abdominal obesity should be incorporated into CVD risk assessments.

Childhood obesity has reached epidemic levels in developed countries. Twenty five percent of children in the US are overweight and 11% are obese. Overweight and obesity in childhood are known to have significant impact on both physical and psychological health. The mechanism of obesity development is not fully understood and it is believed to be a disorder with multiple causes. Environmental factors, lifestyle preferences, and cultural environment play pivotal roles in the rising prevalence of obesity worldwide. In general, overweight and obesity are assumed to be the results of an increase in caloric and fat intake. On the other hand, there are supporting evidence that excessive sugar intake by soft drink, increased portion size, and steady decline in physical activity have been playing major roles in the rising rates of obesity all around the world. Consequently, both over-consumption of calories and reduced physical activity are involved in childhood obesity.Almost all researchers agree that prevention could be the key strategy for controlling the current epidemic of obesity. Prevention may include primary prevention of overweight or obesity, secondary prevention or prevention of weight regains following weight loss, and avoidance of more weight increase in obese persons unable to lose weight. Until now, most approaches have focused on changing the behaviour of individuals in diet and exercise. It seems, however, that these strategies have had little impact on the growing increase of the obesity epidemic. While about 50% of the adults are overweight and obese in many countries, it is difficult to reduce excessive weight once it becomes established. Children should therefore be considered the priority population for intervention strategies. Prevention may be achieved through a variety of interventions targeting built environment, physical activity, and diet. Some of these potential strategies for intervention in children can be implemented by targeting preschool institutions, schools or after-school care services as natural setting for influencing the diet and physical activity. All in all, there is an urgent need to initiate prevention and treatment of obesity in children.

Percentage of body fat is strongly associated with the risk of several chronic diseases but its accurate measurement is difficult. Bioelectrical impedance analysis (BIA) is a relatively simple, quick and non-invasive technique, to measure body composition. It measures body fat accurately in controlled clinical conditions but its performance in the field is inconsistent. In large epidemiologic studies simpler surrogate techniques such as body mass index (BMI), waist circumference, and waist-hip ratio are frequently used instead of BIA to measure body fatness. We reviewed the rationale, theory, and technique of recently developed systems such as foot (or hand)-to-foot BIA measurement, and the elements that could influence its results in large epidemiologic studies. BIA results are influenced by factors such as the environment, ethnicity, phase of menstrual cycle, and underlying medical conditions. We concluded that BIA measurements validated for specific ethnic groups, populations and conditions can accurately measure body fat in those populations, but not others and suggest that for large epdiemiological studies with diverse populations BIA may not be the appropriate choice for body composition measurement unless specific calibration equations are developed for different groups participating in the study.