Combining diaries and accelerometers to explain change in physical activity during a lifestyle intervention for adults with pre-diabetes: A PREVIEW sub-study.

Self-report and device-based measures of physical activity (PA) both have unique strengths and limitations; combining these measures should provide complementary and comprehensive insights to PA behaviours. Therefore, we aim to 1) identify PA clusters and clusters of change in PA based on self-reported daily activities and 2) assess differences in device-based PA between clusters in a lifestyle intervention, the PREVIEW diabetes prevention study. In total, 232 participants with overweight and prediabetes (147 women; 55.9 ± 9.5yrs; BMI ≥25 kg·m-2; impaired fasting glucose and/or impaired glucose tolerance) were clustered using a partitioning around medoids algorithm based on self-reported daily activities before a lifestyle intervention and their changes after 6 and 12 months. Device-assessed PA levels (PAL), sedentary time (SED), light PA (LPA), and moderate-to-vigorous PA (MVPA) were assessed using ActiSleep+ accelerometers and compared between clusters using (multivariate) analyses of covariance. At baseline, the self-reported "walking and housework" cluster had significantly higher PAL, MVPA and LPA, and less SED than the "inactive" cluster. LPA was higher only among the "cycling" cluster. There was no difference in the device-based measures between the "social-sports" and "inactive" clusters. Looking at the changes after 6 months, the "increased walking" cluster showed the greatest increase in PAL while the "increased cycling" cluster accumulated the highest amount of LPA. The "increased housework" and "increased supervised sports" reported least favourable changes in device-based PA. After 12 months, there was only minor change in activities between the "increased walking and cycling", "no change" and "increased supervised sports" clusters, with no significant differences in device-based measures. Combining self-report and device-based measures provides better insights into the behaviours that change during an intervention. Walking and cycling may be suitable activities to increase PA in adults with prediabetes.

Role of Eating Behavior and Stress in Maintenance of Dietary Changes During the PREVIEW Intervention.

OBJECTIVE: To examine whether eating behavior and perceived stress predict the maintenance of self-reported dietary change and adherence to dietary instructions during an intervention. DESIGN: A secondary analysis of the behavior maintenance stage (6-36 months) of the 3-year PREVIEW intervention (PREVention of diabetes through lifestyle Intervention and population studies in Europe and around the World). PARTICIPANTS: Adults (n = 1,311) with overweight and prediabetes at preintervention baseline. VARIABLES MEASURED: Eating behavior (Three-Factor Eating Questionnaire), stress (Perceived Stress Scale), and dietary intake (4-day food records on 4 occasions) were reported. ANALYSIS: Associations between predictors and dietary outcomes were examined with linear mixed-effects models for repeated measurements. RESULTS: Eating behaviors and stress at 6 months did not predict the subsequent change in dietary outcomes, but higher cognitive restraint predicted lower energy intake, and both higher disinhibition and hunger predicted higher energy intake during the following behavior maintenance stage. In addition, higher disinhibition predicted higher saturated fat intake and lower fiber intake, and higher hunger predicted lower fiber intake. Stress was not associated with energy intake or dietary quality. Eating behaviors and stress were not consistently associated with adherence to dietary instructions. CONCLUSIONS AND IMPLICATIONS: Higher cognitive restraint predicted lower energy intake (food quantity), but disinhibition and hunger were also associated with dietary quality.

Associations of obesity phenotypes with weight change, cardiometabolic benefits, and type 2 diabetes incidence during a lifestyle intervention: results from the PREVIEW study.

BACKGROUND/OBJECTIVES: Some individuals with overweight/obesity may be relatively metabolically healthy (MHO) and have a lower risk of cardiovascular disease than those with metabolically unhealthy overweight/obesity (MUO). We aimed to compare changes in body weight and cardiometabolic risk factors and type 2 diabetes incidence during a lifestyle intervention between individuals with MHO vs MUO. METHODS: This post-hoc analysis included 1012 participants with MHO and 1153 participants with MUO at baseline in the randomized trial PREVIEW. Participants underwent an eight-week low-energy diet phase followed by a 148-week lifestyle-based weight-maintenance intervention. Adjusted linear mixed models and Cox proportional hazards regression models were used. RESULTS: There were no statistically significant differences in weight loss (%) between participants with MHO vs MUO over 156 weeks. At the end of the study, weight loss was 2.7% (95% CI, 1.7%-3.6%) in participants with MHO and 3.0% (2.1%-4.0%) in those with MUO. After the low-energy diet phase, participants with MHO had smaller decreases in triglyceride (mean difference between MHO vs MUO 0.08 mmol·L-1 [95% CI, 0.04-0.12]; P < 0.001) but similar reductions in fasting glucose and HOMA-IR than those with MUO. However, at the end of weight maintenance, those with MHO had greater reductions in triglyceride (mean difference -0.08 mmol·L-1 [-0.12--0.04]; P < 0.001), fasting glucose, 2-hour glucose (difference -0.28 mmol·L-1 [-0.41--0.16]; P < 0.001), and HOMA-IR than those with MUO. Participants with MHO had smaller decreases in diastolic blood pressure and HbA1c and greater decreases in HDL cholesterol after weight loss than those with MUO, whereas the statistically significant differences disappeared at the end of weight maintenance. Participants with MHO had lower 3-year type 2 diabetes incidence than those with MUO (adjusted hazard ratio 0.37 [0.20-0.66]; P < 0.001). CONCLUSIONS: Individuals with MUO had greater improvements in some cardiometabolic risk factors during the low-energy diet phase, but had smaller improvements during long-term lifestyle intervention than those with MHO.

Circadian rhythm parameters and physical activity associated with cardiometabolic risk factors in the PREVIEW lifestyle study.

OBJECTIVE: The aim of this study was an assessment of post hoc associations among circadian rhythm parameters, physical activity (PA), and cardiometabolic risk factors in adults with obesity and prediabetes after 3 years of weight loss maintenance. METHODS: Circadian rhythm parameters (continuous wrist-temperature measurements), PA, systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), plasma high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, remnant cholesterol, triacylglycerol, and C-reactive protein (CRP) concentrations were determined in 91 free-living participants (mean [SD], age = 56.6 [10] years; BMI = 28.2 [4.0]; homeostatic model assessment of insulin resistance [HOMA-IR] = 3.2 [3.1]) and in 38 participants in sedentary respiration chamber conditions (age = 56.6 [10] years; BMI = 28.5 [4.0]; HOMA-IR = 3.3 [1.4]). Associations of circadian rhythm parameters and PA with cardiometabolic risk factors were determined using factor analyses followed by Pearson correlations. RESULTS: Values of cardiometabolic risk factors were similar, whereas circadian rhythm parameters and PA differed significantly (p < 0.05) between conditions. In both conditions, parameters indicating a robust circadian rhythm associated inversely with CRP and positively with plasma HDL-C concentrations. In free-living conditions, PA associated inversely with SBP and HR and positively with HDL-C and robust circadian rhythm parameters. In sedentary conditions, PA associated positively with HR and inversely with robust circadian rhythm parameters. PA mediated the inverse association of parameters indicating a robust circadian rhythm with SBP in free-living conditions. CONCLUSIONS: In adults with obesity and prediabetes, parameters indicating a robust circadian rhythm were, independently of PA, associated with lower cardiometabolic risk and CRP. Only in free-living conditions, PA mediated the association of higher circadian stability with lower SBP.

Perceived stress as a predictor of eating behavior during the 3-year PREVIEW lifestyle intervention.

BACKGROUND: To better support participants to achieve long-lasting results within interventions aiming for weight loss and maintenance, more information is needed about the maintenance of behavioral changes. Therefore, we examined whether perceived stress predicts the maintenance of changes in eating behavior (flexible and rigid restraint of eating, disinhibition, and hunger). METHODS: The present study was a secondary analysis of the PREVIEW intervention including participants with overweight (BMI ≥ 25 kg/m2) at baseline and high risk of type 2 diabetes (n = 1311). Intervention included a 2-month low-energy diet phase and a 34-month subsequent weight maintenance phase. The first 6 months were considered an active behavior change stage and the remaining 2.5 years were considered a behavior maintenance stage. Eating behavior was measured using the Three Factor Eating Questionnaire and stress using the Perceived Stress Scale. The associations between stress and eating behavior were analyzed using linear mixed effects models for repeated measurements. RESULTS: Perceived stress measured after the active behavior change stage (at 6 months) did not predict changes in eating behavior during the behavior maintenance stage. However, frequent high stress during this period was associated with greater lapse of improved flexible restraint (p = 0.026). The mean (SD) change in flexible restraint from 6 to 36 months was -1.1 (2.1) in participants with frequent stress and -0.7 (1.8) in participants without frequent stress (Cohen's ds (95% CI) = 0.24 (0.04-0.43)). Higher perceived stress at 6 months was associated with less flexible restraint and more disinhibition and hunger throughout the behavior maintenance stage (all p < 0.001). CONCLUSIONS: Perceived stress was associated with features of eating behavior that may impair successful weight loss maintenance. Future interventions should investigate, whether incorporating stress reduction techniques results in more effective treatment, particularly for participants experiencing a high stress level.

Age- and sex-specific effects of a long-term lifestyle intervention on body weight and cardiometabolic health markers in adults with prediabetes: results from the diabetes prevention study PREVIEW.

AIMS/HYPOTHESIS: Lifestyle interventions are the first-line treatment option for body weight and cardiometabolic health management. However, whether age groups or women and men respond differently to lifestyle interventions is under debate. We aimed to examine age- and sex-specific effects of a low-energy diet (LED) followed by a long-term lifestyle intervention on body weight, body composition and cardiometabolic health markers in adults with prediabetes (i.e. impaired fasting glucose and/or impaired glucose tolerance). METHODS: This observational study used longitudinal data from 2223 overweight participants with prediabetes in the multicentre diabetes prevention study PREVIEW. The participants underwent a LED-induced rapid weight loss (WL) period followed by a 3 year lifestyle-based weight maintenance (WM) intervention. Changes in outcomes of interest in prespecified age (younger: 25-45 years; middle-aged: 46-54 years; older: 55-70 years) or sex (women and men) groups were compared. RESULTS: In total, 783 younger, 319 middle-aged and 1121 older adults and 1503 women and 720 men were included in the analysis. In the available case and complete case analyses, multivariable-adjusted linear mixed models showed that younger and older adults had similar weight loss after the LED, whereas older adults had greater sustained weight loss after the WM intervention (adjusted difference for older vs younger adults -1.25% [95% CI -1.92, -0.58], p<0.001). After the WM intervention, older adults lost more fat-free mass and bone mass and had smaller improvements in 2 h plasma glucose (adjusted difference for older vs younger adults 0.65 mmol/l [95% CI 0.50, 0.80], p<0.001) and systolic blood pressure (adjusted difference for older vs younger adults 2.57 mmHg [95% CI 1.37, 3.77], p<0.001) than younger adults. Older adults had smaller decreases in fasting and 2 h glucose, HbA1c and systolic blood pressure after the WM intervention than middle-aged adults. In the complete case analysis, the above-mentioned differences between middle-aged and older adults disappeared, but the direction of the effect size did not change. After the WL period, compared with men, women had less weight loss (adjusted difference for women vs men 1.78% [95% CI 1.12, 2.43], p<0.001) with greater fat-free mass and bone mass loss and smaller improvements in HbA1c, LDL-cholesterol and diastolic blood pressure. After the WM intervention, women had greater fat-free mass and bone mass loss and smaller improvements in HbA1c and LDL-cholesterol, while they had greater improvements in fasting glucose, triacylglycerol (adjusted difference for women vs men -0.08 mmol/l [-0.11, -0.04], p<0.001) and HDL-cholesterol. CONCLUSIONS/INTERPRETATION: Older adults benefited less from a lifestyle intervention in relation to body composition and cardiometabolic health markers than younger adults, despite greater sustained weight loss. Women benefited less from a LED followed by a lifestyle intervention in relation to body weight and body composition than men. Future interventions targeting older adults or women should take prevention of fat-free mass and bone mass loss into consideration. CLINICAL TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT01777893.

Associations of quantity and quality of carbohydrate sources with subjective appetite sensations during 3-year weight-loss maintenance: Results from the PREVIEW intervention study.

BACKGROUND & AIMS: The association of quantity and quality of carbohydrate sources with appetite during long-term weight-loss maintenance (WLM) after intentional weight loss (WL) is unclear. We aimed to investigate longitudinal associations of quantity and quality of carbohydrate sources with changes in subjective appetite sensations during WLM. METHODS: This secondary analysis evaluated longitudinal data from the 3-year WLM phase of the PREVIEW study, a 2 × 2 factorial (diet-physical activity arms), multi-center, randomized trial. 1279 individuals with overweight or obesity and prediabetes (25-70 years; BMI≥25 kg m-2) were included. Individuals were merged into 1 group to assess longitudinal associations of yearly changes in appetite sensations. Quantity and quality of carbohydrate sources including total carbohydrate, glycemic index (GI), glycemic load (GL), and total dietary fiber were assessed via 4-day food diaries at 4 timepoints (26, 52, 104, and 156 weeks) during WLM. Visual analog scales were used to assess appetite sensations in the previous week. RESULTS: During WLM, participants consumed on average 160.6 (25th, 75th percentiles 131.1, 195.8) g·day-1 of total carbohydrate, with GI 53.8 (48.7, 58.8) and GL 85.3 (67.2, 108.9) g day-1, and 22.3 (17.6, 27.3) g·day-1 of dietary fiber. In the available-case analysis, multivariable-adjusted linear mixed models with repeated measures showed that each 30-g increment in total carbohydrate was associated with increases in hunger (1.36 mm year-1, 95% CI 0.77, 1.95, P < 0.001), desire to eat (1.10 mm year-1, 0.59, 1.60, P < 0.001), desire to eat something sweet (0.99 mm year-1, 0.30, 1.68, P = 0.005), and weight regain (0.20%·year-1, 0.03, 0.36, P = 0.022). Increasing GI was associated with weight regain, but not associated with increases in appetite sensations. Each 20-unit increment in GL was associated with increases in hunger (0.92 mm year-1, 0.33, 1.51, P = 0.002), desire to eat (1.12 mm year-1, 0.62, 1.62, P < 0.001), desire to eat something sweet (1.13 mm year-1, 0.44, 1.81, P < 0.001), and weight regain (0.35%·year-1, 0.18, 0.52, P < 0.001). Surprisingly, dietary fiber was also associated with increases in desire to eat, after adjustment for carbohydrate or GL. CONCLUSIONS: In participants with moderate carbohydrate and dietary fiber intake, and low to moderate GI, we found that higher total carbohydrate, GL, and total fiber, but not GI, were associated with increases in subjective desire to eat or hunger over 3 years. This study was registered as ClinicalTrials.gov, NCT01777893.

Associations of changes in reported and estimated protein and energy intake with changes in insulin resistance, glycated hemoglobin, and BMI during the PREVIEW lifestyle intervention study.

BACKGROUND: Observed associations of high-protein diets with changes in insulin resistance are inconclusive. OBJECTIVES: We aimed to assess associations of changes in both reported and estimated protein (PRep; PEst) and energy intake (EIRep; EIEst) with changes in HOMA-IR, glycated hemoglobin (HbA1c), and BMI (in kg/m2), in 1822 decreasing to 833 adults (week 156) with overweight and prediabetes, during the 3-y PREVIEW (PREVention of diabetes through lifestyle intervention and population studies In Europe and around the World) study on weight-loss maintenance. Eating behavior and measurement errors (MEs) of dietary intake were assessed. Thus, observational post hoc analyses were applied. METHODS: Associations of changes in EIEst, EIRep, PEst, and PRep with changes in HOMA-IR, HbA1c, and BMI were determined by linear mixed-model analysis in 2 arms [high-protein-low-glycemic-index (GI) diet and moderate-protein-moderate-GI diet] of the PREVIEW study. EIEst was derived from energy requirement: total energy expenditure = basal metabolic rate × physical activity level; PEst from urinary nitrogen, and urea. MEs were calculated as [(EIEst - EIRep)/EIEst] × 100% and [(PRep - PEst)/PEst] × 100%. Eating behavior was determined using the Three Factor Eating Questionnaire, examining cognitive dietary restraint, disinhibition, and hunger. RESULTS: Increases in PEst and PRep and decreases in EIEst and EIRep were associated with decreases in BMI, but not independently with decreases in HOMA-IR. Increases in PEst and PRep were associated with decreases in HbA1c. PRep and EIRep showed larger changes and stronger associations than PEst and EIEst. Mean ± SD MEs of EIRep and PRep were 38% ± 9% and 14% ± 4%, respectively; ME changes in EIRep and En% PRep were positively associated with changes in BMI and cognitive dietary restraint and inversely with disinhibition and hunger. CONCLUSIONS: During weight-loss maintenance in adults with prediabetes, increase in protein intake and decrease in energy intake were not associated with decrease in HOMA-IR beyond associations with decrease in BMI. Increases in PEst and PRep were associated with decrease in HbA1c.This trial was registered at clinicaltrials.gov as NCT01777893.

Association of Psychobehavioral Variables With HOMA-IR and BMI Differs for Men and Women With Prediabetes in the PREVIEW Lifestyle Intervention.

OBJECTIVE: Stress, sleep, eating behavior, and physical activity are associated with weight change and insulin resistance (IR). The aim of this analysis was the assessment of the overall and sex-specific associations of psychobehavioral variables throughout the 3-year PREVIEW intervention using the homeostatic model assessment of IR (HOMA-IR), BMI, and length of time in the study. RESEARCH DESIGN AND METHODS: Associations of psychobehavioral variables, including stress, mood, eating behavior, physical activity (PA), and sleep, with BMI, HOMA-IR, and time spent in the study were assessed in 2,184 participants with prediabetes and overweight/obesity (n = 706 men; n = 1,478 women) during a 3-year lifestyle intervention using linear mixed modeling and general linear modeling. The study was a randomized multicenter trial using a 2 × 2 diet-by-PA design. RESULTS: Overall, cognitive restraint and PA increased during the intervention compared with baseline, whereas BMI, HOMA-IR, disinhibition, hunger, and sleepiness decreased (all P < 0.05). Cognitive restraint and PA were negatively, whereas disinhibition, hunger, stress, and total mood disturbance were positively, associated with both BMI and HOMA-IR. Sleep duration, low sleep quality, total mood disturbance, disinhibition, and hunger scores were positively associated with HOMA-IR for men only. Participants who dropped out at 6 months had higher stress and total mood disturbance scores at baseline and throughout their time spent in the study compared with study completers. CONCLUSIONS: Eating behavior and PA, control of stress, mood disturbance, and sleep characteristics were associated with BMI, HOMA-IR, and time spent in the study, with different effects in men and women during the PREVIEW lifestyle intervention study.

Reproducibility and associations with obesity and insulin resistance of circadian-rhythm parameters in free-living vs. controlled conditions during the PREVIEW lifestyle study.

BACKGROUND: Circadian rhythm is altered in individuals with obesity and insulin resistance, showing a smaller amplitude, less stability, and increased intradaily variation. OBJECTIVE: We compared reproducibility of circadian-rhythm parameters over time and under free-living vs. controlled conditions in participants with obesity and pre-diabetes after 2- and 3-year weight-loss maintenance during the 3-year PREVIEW (PREVention of diabetes through lifestyle intervention and population studies In Europe and around the World) study. Associations of obesity and insulin resistance with circadian-rhythm parameters were assessed. SUBJECTS AND METHODS: Circadian-rhythm parameters were determined using continuous wrist-temperature measurements in free-living environments at year 2 (n = 24; age 56.8 ± 10.3 y; body mass index (BMI) = 30 ± 3.9 kg/m2; homeostatic model assessment of insulin resistance (HOMA-IR) 2.4 ± 1.1), at year 3 (n = 97; age 61.7 ± 7.8; BMI = 29.7 ± 3.9; HOMA-IR 2.9 ± 2.1), and at year 3 in a controlled condition (n = 38; age 63.4 ± 6.7; BMI = 28.7 ± 3.9; HOMA-IR 3.8 ± 1.4). Reproducibility was assessed by analyzing repeatability coefficients (CR), differences, and associations, over time as well as between conditions. Associations of BMI and HOMA-IR with circadian-rhythm parameters were assessed at y-3 in both conditions using factor analysis, followed by Pearson's correlations. RESULTS: Reproducibility of circadian-rhythm parameters over time in the free-living environments was high (CR 0.002-5.26; no significant differences; associated amplitudes r = 0.57; p < 0.01). In contrast, reproducibility between different conditions was low (CR 0.02-11.36; significant differences between most parameters (p < 0.05); yet associated amplitudes r = 0.59; p < 0.01). In the controlled vs. free-living condition circadian-rhythm was more stable; BMI and HOMA-IR were associated with the physiological amplitude-related parameters (r = -0.45; p < 0.01; r = -0.33; p < 0.05). In the free-living environment, BMI and behavioral circadian-rhythm parameters indicating circadian alignment, contributed most to the explained variation (47.1%), and were inversely associated (r = -0.22; p < 0.05), while HOMA-IR was inversely associated with stability-related circadian-rhythm parameters (r = -0.21; p < 0.05). CONCLUSIONS: Circadian rhythm was highly reproducible over time in the free-living environments, yet different under different conditions, being more stable in the controlled condition. BMI may play a significant role in circadian alignment and vice versa in the free-living environment.

Dose-Dependent Associations of Dietary Glycemic Index, Glycemic Load, and Fiber With 3-Year Weight Loss Maintenance and Glycemic Status in a High-Risk Population: A Secondary Analysis of the Diabetes Prevention Study PREVIEW.

OBJECTIVE: To examine longitudinal and dose-dependent associations of dietary glycemic index (GI), glycemic load (GL), and fiber with body weight and glycemic status during 3-year weight loss maintenance (WLM) in adults at high risk of type 2 diabetes. RESEARCH DESIGN AND METHODS: In this secondary analysis we used pooled data from the PREVention of diabetes through lifestyle Intervention and population studies in Europe and around the World (PREVIEW) randomized controlled trial, which was designed to test the effects of four diet and physical activity interventions. A total of 1,279 participants with overweight or obesity (age 25-70 years and BMI ≥25 kg ⋅ m-2) and prediabetes at baseline were included. We used multiadjusted linear mixed models with repeated measurements to assess longitudinal and dose-dependent associations by merging the participants into one group and dividing them into GI, GL, and fiber tertiles, respectively. RESULTS: In the available-case analysis, each 10-unit increment in GI was associated with a greater regain of weight (0.46 kg ⋅ year-1; 95% CI 0.23, 0.68; P < 0.001) and increase in HbA1c. Each 20-unit increment in GL was associated with a greater regain of weight (0.49 kg ⋅ year-1; 0.24, 0.75; P < 0.001) and increase in HbA1c. The associations of GI and GL with HbA1c were independent of weight change. Compared with those in the lowest tertiles, participants in the highest GI and GL tertiles had significantly greater weight regain and increases in HbA1c. Fiber was inversely associated with increases in waist circumference, but the associations with weight regain and glycemic status did not remain robust in different analyses. CONCLUSIONS: Dietary GI and GL were positively associated with weight regain and deteriorating glycemic status. Stronger evidence on the role of fiber is needed.

Effect of a high protein/low glycaemic index diet on insulin resistance in adolescents with overweight/obesity-A PREVIEW randomized clinical trial.

BACKGROUND: Pubertal insulin resistance (IR) is associated with increased risk of type 2 diabetes mellitus development in adolescents with overweight/obesity. OBJECTIVES: The PREVIEW study was a randomized parallel trial assessing the change in IR, analyzed by Homeostatic Model Assessment of IR (HOMA-IR), at 2 years after randomization to a high protein vs a moderate protein diet in adolescents with overweight/obesity. It was hypothesized that a high protein/low glycaemic index diet would be superior in reducing IR compared to a medium protein/medium GI diet, in insulin resistant adolescents with overweight or obesity. METHODS: Adolescents with overweight/obesity and IR from the Netherlands, United Kingdom and Spain were randomized into a moderate protein/moderate GI (15/55/30En% protein/carbohydrate/fat, GI ≥ 56) or high protein/low GI (25/45/30En% protein/carbohydrate/fat, GI < 50) diet. Anthropometric and cardiometabolic parameters, puberty, dietary intake and physical activity (PA) were measured and effects on HOMA-IR were analyzed. RESULTS: 126 adolescents were included in this study (13.6 ± 2.2 years, BMI z-score 3.04 ± 0.66, HOMA-IR 3.48 ± 2.28, HP n = 68, MP n = 58). At 2 years, changes in protein intake were not significantly different between timepoints or intervention groups and no effects of the intervention on IR were observed. The retention rate was 39%, while no compliance to the diets was observed. CONCLUSIONS: The PREVIEW study observed no effect of a high protein/low GI diet on IR in adolescents with overweight/obesity and IR because of lack of feasibility, due to insufficient retention and dietary compliance after 2 years.

Goal achievement and adaptive goal adjustment in a behavioral intervention for participants with prediabetes.

Participants with prediabetes were supported to achieve and maintain weight loss with a stage-based behavior change group program named PREview behavior Modification Intervention Toolbox (PREMIT). The tendency to engage in a process of goal adjustment was examined in relation to PREMIT attendance. Analyses were based on 1857 participants who had achieved ⩾8percent weight loss. Tendency to engage in a process of goal adjustment appeared not to be influenced by PREMIT attendance. Instead, results suggested that when unsure about reaching an intervention goal, participants were more likely to engage in a process of goal adjustment, possibly lessening distress due to potentially unachievable goals, either weight loss or maintenance.

Effects of a High-Protein Diet on Cardiometabolic Health, Vascular Function, and Endocannabinoids-A PREVIEW Study.

An unfavorable lipid profile and being overweight are known mediators in the development of cardiovascular disease (CVD) risk. The effect of diet, particularly high in protein, remains under discussion. Therefore, this study examines the effects of a high-protein (HP) diet on cardiometabolic health and vascular function (i.e., endothelial function, arterial stiffness, and retinal microvascular structure), and the possible association with plasma endocannabinoids and endocannabinoid-related compounds in overweight participants. Thirty-eight participants (64.5 ± 5.9 (mean ± SD) years; body mass index (BMI) 28.9 ± 4.0 kg/m2) were measured for 48 h in a respiration chamber after body-weight maintenance for approximately 34 months following weight reduction. Diets with either a HP (n = 20) or moderate protein (MP; n = 18) content (25%/45%/30% vs. 15%/55%/30% protein/carbohydrate/fat) were provided in energy balance. Validated markers for cardiometabolic health (i.e., office blood pressure (BP) and serum lipoprotein concentrations) and vascular function (i.e., brachial artery flow-mediated vasodilation, pulse wave analysis and velocity, and retinal microvascular calibers) were measured before and after those 48 h. Additionally, 24 h ambulatory BP, plasma anandamide (AEA), 2-arachidonoylglycerol (2-AG), oleoylethanolamide (OEA), palmitoylethanolamide (PEA), and pregnenolone (PREG) were analyzed throughout the day. Office and ambulatory BP, serum lipoprotein concentrations, and vascular function markers were not different between the groups. Only heart rate (HR) was higher in the HP group. HR was positively associated with OEA, while OEA and PEA were also positively associated with total cholesterol (TC) and low-density lipoprotein (LDL) cholesterol concentrations. Vascular function markers were not associated with endocannabinoids (or endocannabinoid-related substances). In conclusion, the HP diet did not affect cardiometabolic health and vascular function in overweight participants after completing a weight-loss intervention. Furthermore, our data indicate a possible association between OEA and PEA with TC and LDL cholesterol.

Role of Endocannabinoids in Energy-Balance Regulation in Participants in the Postobese State-a PREVIEW Study.

CONTEXT: Endocannabinoids are suggested to play a role in energy balance regulation. OBJECTIVE: We aimed to investigate associations of endocannabinoid concentrations during the day with energy balance and adiposity and interactions with 2 diets differing in protein content in participants in the postobese phase with prediabetes. DESIGN AND PARTICIPANTS: Participants (n = 38) were individually fed in energy balance with a medium protein (MP: 15:55:30% of energy from protein:carbohydrate:fat) or high-protein diet (HP: 25:45:30% energy from P:C:F) for 48 hours in a respiration chamber. MAIN OUTCOME MEASURES: Associations between energy balance, energy expenditure, respiratory quotient, and endocannabinoid concentrations during the day were assessed. RESULTS: Plasma-concentrations of anandamide (AEA), oleoylethanolamide (OEA), palmitoyethanolamide (PEA), and pregnenolone (PREG) significantly decreased during the day. This decrease was inversely related to body mass index (AEA) or body fat (%) (PEA; OEA). The lowest RQ value, before lunch, was inversely associated with concentrations of AEA and PEA before lunch. Area under the curve (AUC) of concentrations of AEA, 2-AG, PEA, and OEA were positively related to body fat% (P < .05).The HP and MP groups showed no differences in concentrations of AEA, OEA, PEA, and PREG, but the AUC of 2-arachidonoylglycerol (2-AG) was significantly higher in the HP vs the MP group. CONCLUSIONS: In energy balance, only the endocannabinoid 2-AG changed in relation to protein level of the diet, whereas the endocannabinoid AEA and endocannabinoid-related compounds OEA and PEA reflected the gradual energy intake matching energy expenditure during the day.

Sociocognitive factors associated with lifestyle intervention attrition after successful weight loss among participants with prediabetes-The PREVIEW study.

INTRODUCTION: Major risk factors for type 2 diabetes are lifestyle choices such as lack of physical activity (PA) and poor diet. Many individuals either do not take part or struggle to complete interventions supporting lifestyle changes. Demographic and theory-based sociocognitive factors associated with PREVIEW intervention attrition after successful weight loss were examined. METHODS: Participants (1,856) who started the weight maintenance phase after completion of low-energy diet were retrospectively divided into three clusters depending on the point they left the trial. Discriminant analysis examined which demographic and theory-based sociocognitive variables were associated with cluster membership. RESULTS: Most of the participants were women and well-educated. Two discriminant functions were calculated (χ2 (24) = 247.0, p ≥ .05, d = 0.78). The demographic variables, such as age and ethnicity, and the social cognitive variable outcome expectancies on the other side were associated with cluster membership. Older age, Caucasian ethnicity, and fewer expected disadvantages of PA were associated with high success. DISCUSSION: The discriminant model gave insight into some factors associated with early attrition. For practitioners planning interventions it underlines the necessity to take extra attention to younger participants and to those being afraid that being physically active causes unpleasant ramifications.

Compositional analysis of the associations between 24-h movement behaviours and cardio-metabolic risk factors in overweight and obese adults with pre-diabetes from the PREVIEW study: cross-sectional baseline analysis.

BACKGROUND: Physical activity, sedentary time and sleep have been shown to be associated with cardio-metabolic health. However, these associations are typically studied in isolation or without accounting for the effect of all movement behaviours and the constrained nature of data that comprise a finite whole such as a 24 h day. The aim of this study was to examine the associations between the composition of daily movement behaviours (including sleep, sedentary time (ST), light intensity physical activity (LIPA) and moderate-to-vigorous activity (MVPA)) and cardio-metabolic health, in a cross-sectional analysis of adults with pre-diabetes. Further, we quantified the predicted differences following reallocation of time between behaviours. METHODS: Accelerometers were used to quantify daily movement behaviours in 1462 adults from eight countries with a body mass index (BMI) ≥25 kg·m- 2, impaired fasting glucose (IFG; 5.6-6.9 mmol·l- 1) and/or impaired glucose tolerance (IGT; 7.8-11.0 mmol•l- 1 2 h following oral glucose tolerance test, OGTT). Compositional isotemporal substitution was used to estimate the association of reallocating time between behaviours. RESULTS: Replacing MVPA with any other behaviour around the mean composition was associated with a poorer cardio-metabolic risk profile. Conversely, when MVPA was increased, the relationships with cardiometabolic risk markers was favourable but with smaller predicted changes than when MVPA was replaced. Further, substituting ST with LIPA predicted improvements in cardio-metabolic risk markers, most notably insulin and HOMA-IR. CONCLUSIONS: This is the first study to use compositional analysis of the 24 h movement composition in adults with overweight/obesity and pre-diabetes. These findings build on previous literature that suggest replacing ST with LIPA may produce metabolic benefits that contribute to the prevention and management of type 2 diabetes. Furthermore, the asymmetry in the predicted change in risk markers following the reallocation of time to/from MVPA highlights the importance of maintaining existing levels of MVPA. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01777893).

High Compared with Moderate Protein Intake Reduces Adaptive Thermogenesis and Induces a Negative Energy Balance during Long-term Weight-Loss Maintenance in Participants with Prediabetes in the Postobese State: A PREVIEW Study.

BACKGROUND: Weight loss has been associated with adaptations in energy expenditure. Identifying factors that counteract these adaptations are important for long-term weight loss and weight maintenance. OBJECTIVE: The aim of this study was to investigate whether increased protein/carbohydrate ratio would reduce adaptive thermogenesis (AT) and the expected positive energy balance (EB) during weight maintenance after weight loss in participants with prediabetes in the postobese state. METHODS: In 38 participants, the effects of 2 diets differing in protein/carbohydrate ratio on energy expenditure and respiratory quotient (RQ) were assessed during 48-h respiration chamber measurements ∼34 mo after weight loss. Participants consumed a high-protein (HP) diet (n = 20; 13 women/7 men; age: 64.0 ± 6.2 y; BMI: 28.9 ± 4.0 kg/m 2) with 25:45:30% or a moderate-protein (MP) diet (n = 18; 9 women/9 men; age: 65.1 ± 5.8 y; BMI: 29.0 ± 3.8 kg/m 2) with 15:55:30% of energy from protein:carbohydrate:fat. Predicted resting energy expenditure (REEp) was calculated based on fat-free mass and fat mass. AT was assessed by subtracting measured resting energy expenditure (REE) from REEp. The main outcomes included differences in components of energy expenditure, substrate oxidation, and AT between groups. RESULTS: EB (MP = 0.2 ± 0.9 MJ/d; HP = -0.5 ± 0.9 MJ/d) and RQ (MP = 0.84 ± 0.02; HP = 0.82 ± 0.02) were reduced and REE (MP: 7.3 ± 0.2 MJ/d compared with HP: 7.8 ± 0.2 MJ/d) was increased in the HP group compared with the MP group (P < 0.05). REE was not different from REEp in the HP group, whereas REE was lower than REEp in the MP group (P < 0.05). Furthermore, EB was positively related to AT (rs = 0.74; P < 0.001) and RQ (rs = 0.47; P < 0.01) in the whole group of participants. CONCLUSIONS: In conclusion, an HP diet compared with an MP diet led to a negative EB and counteracted AT ∼34 mo after weight loss, in participants with prediabetes in the postobese state. These results indicate the relevance of compliance to an increased protein/carbohydrate ratio for long-term weight maintenance after weight loss. The trial was registered at clinicaltrials.gov as NCT01777893.

Effects of a High-Protein/Moderate-Carbohydrate Diet on Appetite, Gut Peptides, and Endocannabinoids-A Preview Study.

Favorable effects of a high-protein/moderate-carbohydrate (HP/MCHO) diet after weight loss on body weight management have been shown. To extend these findings, associations between perception of hunger and satiety with endocannabinoids, and with glucagon-like peptide-1 (GLP-1) and polypeptide YY (PYY) were assessed. At approximately 34 months after weight loss, 22 female and 16 male participants (mean age 64.5 ± 5.9 years; body mass index (BMI) 28.9 ± 3.9 kg/m2) completed a 48 h respiration chamber study. Participants were fed in energy balance with a HP/MCHO diet with 25%:45%:30% or a moderate-protein/high-carbohydrate (MP/HCHO) diet with 15%:55%:30% of energy from protein:carbohydrate:fat. Endocannabinoids and related compounds, relevant postprandial hormones (GLP-1, PYY), hunger, satiety, and ad libitum food intake were assessed. HP/MCHO versus MP/HCHO reduced hunger perception. The lower decremental area under the curve (dAUC) for hunger in the HP/MCHO diet (-56.6% compared to MP, p < 0.05) was associated with the higher AUC for 2-arachidonoylglycerol (2-AG) concentrations (p < 0.05). Hunger was inversely associated with PYY in the HP/MCHO group (r = -0.7, p < 0.01). Ad libitum food intake, homeostatic model assessment for insulin resistance (HOMA-IR) and incremental AUCs for gut peptides were not different between conditions. HP/MCHO versus MP/HCHO diet-induced reduction in hunger was present after 34 months weight maintenance in the post-obese state. HP/MCHO diet-induced decrease of hunger is suggested to interact with increased 2-AG and PYY concentrations.

Insulin resistance, weight, and behavioral variables as determinants of brain reactivity to food cues: a Prevention of Diabetes through Lifestyle Intervention and Population Studies in Europe and around the World - a PREVIEW study.

Background: Obesity and type 2 diabetes have been linked to alterations in food reward processing, which may be linked to insulin resistance. Objectives: In this clinical study, we investigated the respective contribution of insulin resistance, anthropometric measurements, and behavioral factors to brain reward activation in response to visual stimuli. Design: Food reward-related brain reward activation was assessed with functional magnetic resonance imaging in 39 overweight or obese individuals with impaired fasting glucose, impaired glucose tolerance, or both [22 women, 17 men; mean ± SD insulin sensitivity index (ISI): 2.7 ± 1.3; body mass index (BMI; kg/m2): 32.3 ± 3.7; body fat percentage: 40.5% ± 7.9%; fasting glucose: 6.3 ± 0.6 mmol/L]. Food and nonfood images were shown in a randomized block design. Brain activation (food compared with nonfood images) was correlated with anthropometric and behavioral variables. Behavioral variables included eating behavior [Three-Factor Eating Questionnaire (TFEQ)] and habitual physical activity (Baecke). Glucose and insulin concentrations, determined during an oral-glucose challenge, were used to assess the homeostatic model assessment for insulin resistance (HOMA-IR) and Matsuda ISI. Results: Food compared with nonfood brain activation was positively associated with HOMA-IR in the nucleus accumbens, right and left insula, and right cingulate gyrus (P < 0.005, corrected for multiple comparisons). TFEQ factor 2 was positively related to food compared with nonfood brain activation in the supramarginal gyrus (P < 0.005, corrected for multiple comparisons). Habitual physical activity during leisure time was negatively associated with food compared with nonfood brain activation in multiple regions associated with the attention and reward network (P < 0.005, corrected for multiple comparisons). Conclusions: Individuals with increased insulin resistance and emotional eating or disinhibition showed higher brain reactivity to food cues, which may imply changes in food preference and hyperphagia. Individuals with higher habitual physical activity showed less food reward-related brain activation.