A Worksite-based Dietary and Behavioral Intervention for Weight Loss and Obesity Prevention.
offer great potential to become effective locations for reducing rates of overweight and
obesity; however, the development and testing of innovative worksite weight control
programs is needed to identify approaches that are most effective and sustainable. We
conducted a 6-month, worksite-randomized controlled pilot study aimed to determine
whether a dietary and behavioral ... read moreintervention in worksites in the Greater Boston area
would lead to significant changes in body weight and cardiometabolic risk factors for
chronic disease. The intervention combined recommendations to consume a reduced energy,
high fiber, low-glycemic load diet with education on nutrition and behavior change, and
a subsequent 6-month structured weight maintenance program. Concurrently, a
low-intensity health and nutrition education program was available to all employees.
Furthermore, a sub-group of employees underwent functional magnetic resonance imaging
(fMRI) to examine changes in region-specific brain activation in response to
high-glycemic load and low-glycemic load food images before and after participation in
the weight loss intervention. Mean weight loss was substantial in program participants
whereas wait-listed controls gained weight (-8.0 ± 0.7kg versus +0.9 ± 0.5kg,
P<0.0001). There were improvements in cardiometabolic risk factors in intervention
subjects as compared to controls: fasting total cholesterol (-13.21 ± 2.95mg/dl
versus +0.76 ± 3.74mg/dl, P=0.01), LDL-C (-13.47 ± 2.67mg/dl versus -4.70
± 3.94mg/dl, P=0.05), glucose (-6.37 ± 1.55mg/dl versus +6.31 ±
3.55mg/dl, P<0.001), systolic blood pressure (-8.51 ± 1.47mmHg versus +5.50
± 2.08mmHg, P<0.0001), and in diastolic blood pressure (-8.14 ± 1.27mmHg
versus -0.5 ± 1.28mmHg, P<0.001). There was no significant increase in body
weight during the structured maintenance program (0.5 ± 0.7kg, P=0.65).
Furthermore, overweight and obese employees in intervention worksites who did not enroll
in the weight loss program also lost weight compared to those in the wait-listed control
worksites (-1.3 ± 0.5kg versus +0.7 ± 0.6kg, P=0.03). In addition, there were
changes in activation in regions of the prefrontal cortex, including the anterior
cingulate and insula, as well as in the dorsal striatum in response to high-glycemic
load and low-glycemic food images among the sub-group of employees who underwent fMRI
scans pre- and post-intervention. In conclusion, this pilot study demonstrated that
worksites can be effective locations for achieving clinically significant reductions in
body weight and improvements in cardiometabolic risk factors. Our findings also provide
the first evidence that a dietary and behavioral intervention for weight loss can lead
to differential changes in activation in response to high-glycemic and low-glycemic load
food stimuli in regions of the brain associated with food
Thesis (Ph.D.)--Tufts University, 2012.
Submitted to the Dept. of Biochemical and Molecular Nutrition.
Advisor: Susan Roberts.
Committee: Susan Roberts, Sai Krupa Das, Alice Lichtenstein, and Thilo Deckersbach.
Keyword: Nutrition.read less