A randomized controlled trial comparing prevention and promotion cognitive strategies in a behavioral weight-loss intervention.

OBJECTIVE: Two approaches may shift attention from short-term rewards to longer-term weight-loss goals: focusing on long-term consequences of unhealthy choices (prevention) or benefits of healthy choices (promotion). This randomized controlled trial tested the impact of prevention- versus promotion-focused strategies in an internet-delivered behavioral weight-loss intervention (iBWL). METHODS: A total of 95 participants with overweight/obesity were randomized to one of three 12-week iBWLs: (1) STANDARD (n = 31), (2) PREVENT (standard iBWL+prevention-focused training; n = 32), or (3) PROMOTE (standard iBWL+promotion-focused training; n = 32). Participants in the two enhanced arms were trained in their assigned strategy, and lessons and weekly feedback featured arm-specific content and reminders. RESULTS: Intent-to-treat analysis revealed significant differences in weight loss and self-control use at 12 weeks (weight loss p = 0.002, self-control p = 0.0006). PREVENT was associated with 6.6% (±4.5%) weight loss and a 20.3% (±26.5%) increase in self-control, STANDARD and PROMOTE were associated with 4.4% (±4.2%) and 3.1% (±3.1%) weight losses, respectively, and neither STANDARD nor PROMOTE participants exhibited significant changes in self-control. Across arms, increased self-control was associated with greater weight loss (p = 0.0005). CONCLUSIONS: Cognitive strategies to focus on preventing negative consequences of unhealthy choices led to greater weight loss and self-control compared with both standard iBWL and promotion-focused iBWL. Prevention strategies should be given further attention for overweight/obesity treatment.

Effects of Cognitive Strategies on Neural Food Cue Reactivity in Adults with Overweight/Obesity.

OBJECTIVE: Functional magnetic resonance imaging (fMRI) studies of obesity have revealed key roles for reward-related and inhibitory control-related activity in response to food cues. This study examines how cognitive strategies impact neural food cue reactivity. METHODS: In a within-participants, block-design, fMRI paradigm, 30 participants (24 women; mean BMI = 31.8) used four mind-sets while viewing food: "distract" (cognitive behavioral therapy based), "allow" (acceptance and commitment therapy based), "later" (focusing on long-term negative consequences), and "now" (control; focusing on immediate rewards). Participants rated cravings by noting urges to eat on four-point Likert scales after each block. RESULTS: Self-reported cravings significantly differed among all conditions (pairwise comparisons P < 0.05). Cravings were lowest when participants considered long-term consequences (LATER mind-set: 1.7 [SD 0.7]), were significantly higher when participants used the DISTRACT (1.9 [SD 0.7]) and ALLOW (2.3 [SD 0.9]) mind-sets, and were highest when participants used the NOW mind-set (3.2 [SD 0.7]). These behavioral differences were accompanied by differences in neural food cue reactivity. The LATER mind-set (long-term consequences) led to greater inhibitory-control activity in the dorsolateral prefrontal cortex. The cognitive behavioral therapy-based DISTRACT mind-set was associated with greater activity in executive function and reward-processing areas, whereas the ALLOW mind-set (acceptance and commitment therapy) elicited widespread activity in frontal, reward-processing, and default-mode regions. CONCLUSIONS: Because focusing on negative long-term consequences led to the greatest decrease in cravings and increased inhibitory control, this may be a promising treatment strategy for obesity.

Long-term impact of intensive lifestyle intervention on cognitive function assessed with the National Institutes of Health Toolbox: The Look AHEAD study.

INTRODUCTION: This study sought to determine whether 10 years of assignment to intensive lifestyle intervention (ILI) relative to diabetes support and education leads to better cognition. We examine intervention effects overall and among clinical subgroups, and report correlations between computer-administered and interviewer-administered cognitive batteries. METHODS: The Action for Health in Diabetes (Look AHEAD) was a 16-site randomized controlled trial with overweight/obese individuals (aged 45-76) who had type 2 diabetes. The NIH Toolbox Cognition Battery tests developed to measure cognition across the lifespan were used to evaluate cognition. Results were compared with standard paper-and-pencil tests. The Toolbox and paper-and-pencil tests were administered an average of 10.9 years after randomization to 1002 participants. RESULTS: Toolbox measures significantly correlated with interviewer-administered measures, with the strongest correlations between the Toolbox Fluid Cognition Composite and Trails B (r = -0.64, P < .0001) and Digit Symbol Coding (r = 0.63, P < .0001), and between the Toolbox Dimensional Change Card Sort (r = 0.55, P < .0001) and the Digit Symbol Coding test. Overall, ILI and diabetes support and education groups had similar adjusted mean cognitive outcomes (P > .05 for all). Subgroup analyses identified different intervention effects within baseline body mass index groups for Picture Sequence Memory (P = .01), within baseline cardiovascular disease groups for Picture Vocabulary (P = .01) and Fluid Cognition Composite (P = .02) measures, and within baseline age groups for Picture Vocabulary (P = .02). DISCUSSION: Correlations between Toolbox and interviewer-administered outcomes provide a measure of internal validity. Findings suggest no overall effect of the intervention on cognition and that an ILI resulting in weight loss may have negative implications for cognition in individuals aged ≥60, with previous history of cardiovascular disease, and those with body mass index ≥40.

Effect of a long-term intensive lifestyle intervention on prevalence of cognitive impairment.

OBJECTIVE: To assess whether an average of 10 years of lifestyle intervention designed to reduce weight and increase physical activity lowers the prevalence of cognitive impairment among adults at increased risk due to type 2 diabetes and obesity or overweight. METHODS: Central adjudication of mild cognitive impairment and probable dementia was based on standardized cognitive test battery scores administered to 3,802 individuals who had been randomly assigned, with equal probability, to either the lifestyle intervention or the diabetes support and education control. When scores fell below a prespecified threshold, functional information was obtained through proxy interview. RESULTS: Compared with control, the intensive lifestyle intervention induced and maintained marked differences in weight loss and self-reported physical activity throughout follow-up. At an average (range) of 11.4 (9.5-13.5) years after enrollment, when participants' mean age was 69.6 (54.9-87.2) years, the prevalence of mild cognitive impairment and probable dementia was 6.4% and 1.8%, respectively, in the intervention group, compared with 6.6% and 1.8%, respectively, in the control group (p = 0.93). The lack of an intervention effect on the prevalence of cognitive impairment was consistent among individuals grouped by cardiovascular disease history, diabetes duration, sex, and APOE ε4 allele status (all p ≥ 0.50). However, there was evidence (p = 0.03) that the intervention effect ranged from benefit to harm across participants ordered from lowest to highest baseline BMI. CONCLUSIONS: Ten years of behavioral weight loss intervention did not result in an overall difference in the prevalence of cognitive impairment among overweight or obese adults with type 2 diabetes. CLINICALTRIALSGOV IDENTIFIER: NCT00017953 (Action for Health in Diabetes). LEVEL OF EVIDENCE: This study provides Class II evidence that for overweight adults with type 2 diabetes, a lifestyle intervention designed to reduce weight and increase physical activity does not lower the risk of cognitive impairment.

Effect of a Long-Term Intensive Lifestyle Intervention on Cognitive Function: Action for Health in Diabetes Study.

OBJECTIVES: To assess whether randomization to 10 years of lifestyle intervention to induce and maintain weight loss improves cognitive function. DESIGN: Randomized controlled clinical trial. SETTING: Data obtained as part of the Action for Health in Diabetes (Look AHEAD) trial (NCT00017953) and Look AHEAD Continuation study (U01 DK057136-15). PARTICIPANTS: Overweight and obese individuals with type 2 diabetes mellitus aged 45 to 76 (N = 3,751). INTERVENTION: Intensive lifestyle intervention (ILI) for weight loss through reduced caloric intake and increased physical activity compared with a control condition of diabetes support and education (DSE). MEASUREMENTS: Certified examiners who were masked to intervention assignment administered a standard battery of cognitive function tests (Modified Mini-Mental State Examination, Rey Auditory Verbal Learning Test, Digit Symbol Coding, Trail-Making Test, Modified Stroop Color-Word Test) to participants 10 to 13 years after enrollment. RESULTS: Assignment to lifestyle intervention was not associated with significantly different overall (P = .10) or domain-specific (all P > .10) cognitive function than assignment to diabetes support and education. Results were fairly consistent across prespecified groups, but there was some evidence of trends for differential intervention effects showing modest harm in ILI in participants with greater body mass index and in individuals with a history of cardiovascular disease. Cognitive function was not associated with changes in weight or fitness (all P > .05). CONCLUSION: A long-term behavioral weight loss intervention for overweight and obese adults with diabetes mellitus was not associated with cognitive benefit. Trial Registration clinicaltrials.gov Identifier: NCT00017953.

Brain and White Matter Hyperintensity Volumes After 10 Years of Random Assignment to Lifestyle Intervention.

OBJECTIVE: Type 2 diabetes increases the accumulation of brain white matter hyperintensities and loss of brain tissue. Behavioral interventions to promote weight loss through dietary changes and increased physical activity may delay these adverse consequences. We assessed whether participation in a successful 10-year lifestyle intervention was associated with better profiles of brain structure. RESEARCH DESIGN AND METHODS: At enrollment in the Action for Health in Diabetes clinical trial, participants had type 2 diabetes, were overweight or obese, and were aged 45-76 years. They were randomly assigned to receive 10 years of lifestyle intervention, which included group and individual counseling, or to a control group receiving diabetes support and education through group sessions on diet, physical activity, and social support. Following this intervention, 319 participants from three sites underwent standardized structural brain magnetic resonance imaging and tests of cognitive function 10-12 years after randomization. RESULTS: Total brain and hippocampus volumes were similar between intervention groups. The mean (SE) white matter hyperintensity volume was 28% lower among lifestyle intervention participants compared with those receiving diabetes support and education: 1.59 (1.11) vs. 2.21 (1.11) cc (P = 0.02). The mean ventricle volume was 9% lower: 28.93 (1.03) vs. 31.72 (1.03) cc (P = 0.04). Assignment to lifestyle intervention was not associated with consistent differences in cognitive function compared with diabetes support and education. CONCLUSIONS: Long-term weight loss intervention may reduce the adverse impact of diabetes on brain structure. Determining whether this eventually delays cognitive decline and impairment requires further research.