Nine-year incidence of obesity and overweight in an African-origin population

To provide 9-year incidence estimates for obesity and overweight and describe weight changes over time in an African-origin population.

A population-based cohort in which participants were examined at baseline and reexamined after 9 years.

Obesity and overweight were defined as having body mass indices (BMIs)> or =30 and 25 kg m(-2), respectively. Incidence rates were based on persons without such conditions at baseline and are presented along with 95% confidence intervals.

Of the 869 men and 921 women at risk at baseline, the 9-year gender-specific incidence rates for obesity were 6.9% (95% confidence interval (5.3, 8.8)) and 13.1% (11.0, 15.5), respectively. The incidence of obesity steadily declined with age, decreasing from 14.4% for those between 40 and 49 years of age to 1.5% for those who were 70 years and older. Overall, the incidence of obesity over 9 years was approximately 10%. The 9-year incidence rate for overweight was 23.3% (20.5, 26.3). Changes in weight over the 9-year period varied by age group. Persons 40-49 years of age at baseline gained, on average, almost 3% of their baseline body weight, whereas persons > or =70 years lost 5% of their body weight in 9 years.

This study highlights the high incidence of obesity/overweight in this cohort and suggests that the future public health burden of excess weight and its associated comorbidities may be elevated in this population of African origin. The development of strategies and interventions for the prevention and treatment of obesity/overweight are therefore of primary and immediate importance.