Objectives: The objectives of this pilot study were to compare the dietary, physiological and metabolic effects of 12-week modified carbohydrate nutrition intervention when disseminated in an individualized home-based format versus a group classroom-based format.
Methods: Twenty-three overweight (>/=85(th) percentile BMI) Latina adolescent females (12-17 years of age) were randomized to a 12-week modified carbohydrate dietary intervention delivered in either an individualized home-based format (n = 11) or a group classroom-based format (n = 12). Anthropometrics, dietary intake by 3-day diet records, insulin dynamics by extended 3-hour Oral Glucose Tolerance test (OGTT) and body composition by Dual energy X-ray absorptiometry (DXA) were measured before and after intervention; 24-hour diet recalls were collected once or twice per month throughout the program.
Results: Mixed modeling showed no significant differences in changes in dietary intake between intervention groups, but both groups significantly reduced intake of added sugar, sugary beverages and refined carbohydrates by 33%, 66%, and 35%, respectively, and dietary fiber significantly increased by 44% (p <0.01) throughout the 12 weeks. There was a significant time effect for BMI z-scores within each intervention group (p <0.05). There was no significant time*intervention group interaction for any of the physiological or metabolic variables, indicating that change over time was not significantly different between intervention groups.
Conclusions: Although a culturally tailored, modified carbohydrate dietary intervention led to significant improvements in dietary intake and BMI z-scores, the extremely intensive, individualized, home-based program was no more effective at improving diet, decreasing adiposity or reducing type 2 diabetes risk factors than the traditional classroom-based format.