Evaluating a transtheoretical model-based ‘non-diet’ intervention in college aged students

Background. The prevalence of overweight and obesity continues to rise in childhood and throughout adulthood in the United States. Targeting the population of young adults may be the best strategy since they are at high risk for weight gain, especially freshman in college. Traditional dietary interventions or weight loss programs have shown evidence of short-term benefits with little data to support long-term, lasting weight loss for most participants. The Transtheoretical Models (TTM) stages of motivational readiness to change can assist with behavior change in some populations. Nondieting advocates increase in fitness, rather than a decrease in weight and the main focus is on improving health using long-term lifestyle changes. Objective. Examine whether a TTM-based non-diet intervention will affect the weight, dietary restraint, dietary disinhibition, physical activity, fruit and vegetable intake and biochemical indices of the subjects receiving the intervention compared to others receiving a TTM-based fruit and vegetable intervention. Design. 10-week, randomized, controlled pilot study. Participants/setting- University of Rhode Island students (72% freshman) of normal weight and health (n=71) were 76% female and 90% Caucasian. Intervention- 10 weekly home-study lessons, activities along with feedback by a registered dietitian (non-diet program or fruit & vegetable program). Main outcome measures. Anthropometry (weight, waist circumference), physical fitness (MET minutes per week and VO2max), eating behavior (dietary restraint, dietary disinhibition, hunger scores), fruit and vegetable intake (perceived and self-assessed) and biochemical (fasting plasma total cholesterol, triglycerides and glucose). Statistical analyses performed. Student’s t-tests, paired t- tests and analysis of variance. Results. Both groups had no change in weight or waist circumference over the 10 week study period. Dietary restraint increased in the fruit and vegetable group and hunger scores decreased in the non-diet group. Perceived intake of fruits and vegetables increased in both groups, however, self-assessed intake only increased in the fruit and vegetable intervention group. Fasting plasma glucose decreased in the non-diet group. Conclusions. These 10 week TTM-based non-diet and fruit and vegetable-focused interventions both had no effect on weight in college students. A TTM-based fruit and vegetable-focused intervention is successful at increasing the subjects’ fruit and vegetable intake. Physical activity-focused lessons in the non-diet group did not help to increase the amount of exercise or the VO2max of college students