Body mass trajectories through midlife among adults with class I obesity

Little is known about the body mass trajectories for adults with class I obesity. Our objective was to map the body mass trajectories through midlife for young adults with class I obesity in the United States.

Data from the National Longitudinal Study of Youth 1979 was used to generate a cohort of 1058 men and women, aged 25-33 years with class I obesity in 1990. Group-based trajectory modeling was used to identify the number and shape of the body mass index trajectories from 1990 to 2008 for this cohort.

By 2008, about 15% of men and women with class I obesity in 1990 experienced a body mass index increase to >40 kg/m(2). The trajectory analyses showed that roughly one third of the sample were on 1 of 2 body mass index trajectory groups that culminated with an average BMI well above 35 kg/m(2).

The large majority of young adults with class I obesity are likely to gain weight over time. For many, the weight gain will be significant and greatly increase their risk of obesity-related co-morbidities and reduced life expectancy. As a result, bariatric surgery or other intensive weight management options might be warranted.