BestFIT Sequential Multiple Assignment Randomized Trial Results: A SMART Approach to Developing Individualized Weight Loss Treatment Sequences.

BACKGROUND: State-of-the-art behavioral weight loss treatment (SBT) can lead to clinically meaningful weight loss, but only 30-60% achieve this goal. Developing adaptive interventions that change based on individual progress could increase the number of people who benefit. PURPOSE: Conduct a Sequential Multiple Assignment Randomized Trial (SMART) to determine the optimal time to identify SBT suboptimal responders and whether it is better to switch to portion-controlled meals (PCM) or acceptance-based treatment (ABT). METHOD: The BestFIT trial enrolled 468 adults with obesity who started SBT and were randomized to treatment response assessment at Session 3 (Early TRA) or 7 (Late TRA). Suboptimal responders were re-randomized to PCM or ABT. Responders continued SBT. Primary outcomes were weight change at 6 and 18 months. RESULTS: PCM participants lost more weight at 6 months (-18.4 lbs, 95% CI -20.5, -16.2) than ABT participants (-15.7 lbs, 95% CI: -18.0, -13.4), but this difference was not statistically significant (-2.7 lbs, 95% CI: -5.8, 0.5, p = .09). PCM and ABT participant 18 month weight loss did not differ. Early and Late TRA participants had similar weight losses (p = .96), however, Early TRA PCM participants lost more weight than Late TRA PCM participants (p = .03). CONCLUSIONS: Results suggest adaptive intervention sequences that warrant further research (e.g., identify suboptimal responders at Session 3, use PCMs as second-stage treatment). Utilizing the SMART methodology to develop an adaptive weight loss intervention that would outperform gold standard SBT in a randomized controlled trial is an important next step, but may require additional optimization work. CLINICAL TRIAL INFORMATION: ClinicalTrials.gov identifier; NCT02368002.

Reduced Ambient PM2.5 Was Associated with a Decreased Risk of Chronic Kidney Disease: A Longitudinal Cohort Study.

Many countries have dedicated to the mitigation of air pollution in the past several decades. However, evidence of beneficial effects of air quality improvement on chronic kidney disease (CKD) remains limited. We thus investigated the effects of dynamic changes (including deterioration and improvement) in air quality on the incidence of CKD in a longitudinal study in Taiwan. During 2001-2016, this study recruited a total of 163,197 Taiwanese residents who received at least two standard physical examinations. The level of fine particle matter (PM2.5) was estimated using a high-resolution (1 km2) satellite-based spatio-temporal model. We defined changes of PM2.5 concentrations (ΔPM2.5) as the difference between the two-year average measurements during follow-up and during the immediately preceding visit. The time-dependent Cox regression model was adopted to evaluate the relationships between ΔPM2.5 and the incidence of CKD after adjusting for a series of covariates. The concentrations of PM2.5 in Taiwan peaked around 2004 and began to decrease since 2005. We observed an approximate linear concentration-response relationship of ΔPM2.5 with CKD incidence. Every 5 µg/m3 decrease in the ambient concentration of PM2.5 was associated with a 25% reduced risk of CKD development [hazard ratio (HR): 0.75; 95% CI: 0.73, 0.78]. In conclusion, this study demonstrated that the improvement of PM2.5 air quality might be associated with a lower risk of CKD development. Our findings indicate that reducing air pollution may effectively prevent the development of CKD.

Lifestyle Intervention and Medical Management With vs Without Roux-en-Y Gastric Bypass and Control of Hemoglobin A1c, LDL Cholesterol, and Systolic Blood Pressure at 5 Years in the Diabetes Surgery Study.

Importance: The Roux-en-Y gastric bypass is effective in achieving established diabetes treatment targets, but durability is unknown. Objective: To compare durability of Roux-en-Y gastric bypass added to intensive lifestyle and medical management in achieving diabetes control targets. Design, Setting, and Participants: Observational follow-up of a randomized clinical trial at 4 sites in the United States and Taiwan, involving 120 participants who had a hemoglobin A1c (HbA1c) level of 8.0% or higher and a body mass index between 30.0 and 39.9 (enrolled between April 2008 and December 2011) were followed up for 5 years, ending in November 2016. Interventions: Lifestyle-intensive medical management intervention based on the Diabetes Prevention Program and LookAHEAD trials for 2 years, with and without (60 participants each) Roux-en-Y gastric bypass surgery followed by observation to year 5. Main Outcomes and Measures: The American Diabetes Association composite triple end point of hemoglobin A1c less than 7.0%, low-density lipoprotein cholesterol less than 100 mg/dL, and systolic blood pressure less than 130 mm Hg at 5 years. Results: Of 120 participants who were initially randomized (mean age, 49 years [SD, 8 years], 72 women [60%]), 98 (82%) completed 5 years of follow-up. Baseline characteristics were similar between groups: mean (SD) body mass index 34.4 (3.2) for the lifestyle-medical management group and 34.9 (3.0) for the gastric bypass group and had hemoglobin A1c levels of 9.6% (1.2) and 9.6% (1.0), respectively. At 5 years, 13 participants (23%) in the gastric bypass group and 2 (4%) in the lifestyle-intensive medical management group had achieved the composite triple end point (difference, 19%; 95% CI, 4%-34%; P = .01). In the fifth year, 31 patients (55%) in the gastric bypass group vs 8 (14%) in the lifestyle-medical management group achieved an HbA1c level of less than 7.0% (difference, 41%; 95% CI, 19%-63%; P = .002). Gastric bypass had more serious adverse events than did the lifestyle-medical management intervention, 66 events vs 38 events, most frequently gastrointestinal events and surgical complications such as strictures, small bowel obstructions, and leaks. Gastric bypass had more parathyroid hormone elevation but no difference in B12 deficiency. Conclusions and Relevance: In extended follow-up of obese adults with type 2 diabetes randomized to adding gastric bypass compared with lifestyle and intensive medical management alone, there remained a significantly better composite triple end point in the surgical group at 5 years. However, because the effect size diminished over 5 years, further follow-up is needed to understand the durability of the improvement. Trial Registration: clinicaltrials.gov Identifier: NCT00641251.

Feasibility of standardized methods to specify behavioral pediatric obesity prevention interventions.

Standardized methods are needed to evaluate what occurs within the 'black box' of behavioral interventions to prevent pediatric obesity. The purpose of this research is to evaluate methods to specify the behavior change techniques used and the amount of time spent discussing target weight-related behaviors in an intervention for parents of children at risk for becoming overweight or obese. Independent coders were trained to identify behavior change techniques and time spent discussing weight-related behaviors in audio recordings and transcripts of intervention sessions from 100 randomly selected participants. The behavior change technique taxonomy (BCTTv1) was used to code techniques present in sessions. A newly-developed tool was used to code time spent discussing each target weight-related behavior (e.g., physical activity, screen time). Sessions from a subset of these participants (N = 20) were double coded to evaluate inter-rater reliability. After revisions to coding protocols, coders reliably coded behavior change techniques used and time spent discussing target weight-related behaviors in sessions from the subset of 20 participants. The most commonly discussed target weight-related behavior was physical activity followed by energy intake and fruit and vegetable intake. On average, 13.9 (SD = 2.8) unique behavior change techniques were present across sessions for a given participant. These results offer reliable methods for systematically identifying behavior change techniques used and time spent discussing weight-related behaviors in a pediatric obesity prevention intervention. This work paves the way for future research to identify which specific target behaviors and techniques are most associated with the prevention of unhealthy weight gain in children.

Cardiovascular effects of intensive lifestyle intervention in type 2 diabetes.

BACKGROUND: Weight loss is recommended for overweight or obese patients with type 2 diabetes on the basis of short-term studies, but long-term effects on cardiovascular disease remain unknown. We examined whether an intensive lifestyle intervention for weight loss would decrease cardiovascular morbidity and mortality among such patients. METHODS: In 16 study centers in the United States, we randomly assigned 5145 overweight or obese patients with type 2 diabetes to participate in an intensive lifestyle intervention that promoted weight loss through decreased caloric intake and increased physical activity (intervention group) or to receive diabetes support and education (control group). The primary outcome was a composite of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for angina during a maximum follow-up of 13.5 years. RESULTS: The trial was stopped early on the basis of a futility analysis when the median follow-up was 9.6 years. Weight loss was greater in the intervention group than in the control group throughout the study (8.6% vs. 0.7% at 1 year; 6.0% vs. 3.5% at study end). The intensive lifestyle intervention also produced greater reductions in glycated hemoglobin and greater initial improvements in fitness and all cardiovascular risk factors, except for low-density-lipoprotein cholesterol levels. The primary outcome occurred in 403 patients in the intervention group and in 418 in the control group (1.83 and 1.92 events per 100 person-years, respectively; hazard ratio in the intervention group, 0.95; 95% confidence interval, 0.83 to 1.09; P=0.51). CONCLUSIONS: An intensive lifestyle intervention focusing on weight loss did not reduce the rate of cardiovascular events in overweight or obese adults with type 2 diabetes. (Funded by the National Institutes of Health and others; Look AHEAD ClinicalTrials.gov number, NCT00017953.).

Effect of an intensive lifestyle intervention on atrial fibrillation risk in individuals with type 2 diabetes: the Look AHEAD randomized trial.

BACKGROUND: Obesity is associated with higher risk of atrial fibrillation (AF), but the impact of behavioral weight loss interventions on atrial fibrillation (AF) risk in persons with diabetes is unknown. We addressed this question in the Look AHEAD randomized trial. METHODS AND RESULTS: A total of 5,067 overweight or obese individuals 45 to 76 years old with type 2 diabetes without prevalent AF were randomized to either an intensive lifestyle intervention (ILI) designed to achieve and maintain weight loss through caloric reduction and increased physical activity or a diabetes support and education usual care group. Atrial fibrillation was ascertained from electrocardiograms at study examinations and hospitalization discharge summaries. Multivariable Cox models were used to estimate the intention-to-treat effect of the intervention adjusting for baseline covariates. During a mean follow-up of 9.0 years, 294 incident AF cases were identified. Rates of AF were comparable in the ILI and diabetes support and education groups (6.1 and 6.7 cases per 1,000 person-years, respectively, P = .42). The intervention did not affect AF incidence (multivariable hazard ratio [HR] 0.99, 95% CI 0.77-1.28). Similarly, neither weight loss nor improvement in physical fitness during the first year of the intervention was significantly associated with AF incidence: multivariable hazard ratio (95% CI) comparing top versus bottom quartile was 0.70 (0.41-1.18) for weight loss and 0.88 (0.55-1.43) for physical fitness improvement. CONCLUSION: In a large randomized trial of overweight and obese individuals with type 2 diabetes, an ILI that induced modest weight loss did not reduce the risk of developing AF.

Questionnaire and laboratory measures of eating behavior. Associations with energy intake and BMI in a community sample of working adults.

PURPOSE: The present research compared a self-report measure of usual eating behaviors with two laboratory-based behavioral measures of food reward and food preference. METHODS: Eating behaviors were measured among 233 working adults. A self-report measure was the Three Factor Eating Questionnaire (TFEQ) Restraint, Disinhibition and Hunger subscales. Laboratory measures were the (RVF) and Explicit Liking (EL) and Implicit Wanting (IW) for high fat food. Outcome measures were body mass index (BMI), and energy intake measured using three 24-h dietary recalls. RESULTS: Significant bivariate associations were observed between each of the eating behavior measures and energy intake, but only Disinhibition and Hunger were associated with BMI. Multiple regression results showed RVF and EL and IW predicted energy intake independent of the TFEQ scales but did not predict BMI. CONCLUSION: Laboratory and self-report measures capture unique aspects of individual differences in eating behaviors that are associated with energy intake.

Behavior and weight correlates of weight-control efforts in Australian women living in disadvantage: The READI study.

BACKGROUND: With increasing obesity rates worldwide, more and more people are actively attempting to lose weight or avoid weight gain, but relatively little is known about what specific behaviors comprise these efforts and which, if any, are associated with better weight control over time. METHODS: This paper reports relationships between body weight, weight-control efforts and related behaviors over a three-year period in 1,634 Australian women. The women were purposefully recruited from 80 disadvantaged neighborhoods in Victoria, Australia. Weight loss efforts were categorized as trying to lose weight, trying to prevent weight gain and no weight-control efforts. Behavioral correlates examined included different kinds of physical activity and consumption of a number of specific foods types. RESULTS AND DISCUSSION: Self-reported body weight at baseline was higher in women trying to lose weight. Frequency of consumption of low energy density foods was positively associated with reported weight-control efforts, as was frequency of reported total and leisure-time physical activity. Longitudinal associations between changes in weight-control efforts and changes in behaviors were consistent with the cross-sectional findings. At three-year follow up, however, weight-control efforts were not associated with change in body weight. More detailed analyses of specific food choices suggested that part of the explanation of no effect of reported weight-control efforts and weight over time might be that people are not as well-informed as they should be about the energy density of some common foods. In particular, those reporting engagement in weight-control efforts reported reducing consumption of carbohydrate-containing foods such as bread and potatoes more than is justified by their energy content, while they reported increasing consumption of some high energy density foods (e.g., cheese and nuts). CONCLUSION: It is tentatively concluded that women living in disadvantaged neighborhoods understand messages about weight-control (more activity and foods with lower fat and lower energy density) but that some foods eaten more by women engaged in weight control may reduce the effectiveness of these efforts.

Enhancing long-term weight loss maintenance: 2 year results from the Keep It Off randomized controlled trial.

OBJECTIVE: The Keep It Off trial evaluated the efficacy of a phone-based weight loss maintenance intervention among adults who had recently lost weight in Minnesota (2007-2010). METHODS: 419 adults who had recently lost ≥ 10% of their body weight were randomized to the "Guided" or "Self-Directed" intervention. Guided participants received a 10 session workbook, 10 biweekly, eight monthly and six bimonthly phone coaching calls, bimonthly weight graphs and tailored letters based on self-reported weights. Self-Directed participants received the workbook and two calls. Primary outcomes are weight change and maintenance (regain of <2.5% of baseline body weight). RESULTS: Mixed model repeated-measures analysis examining weight change revealed a significant time by treatment group interaction (p<0.0085). Guided participants regained significantly less weight than the Self-Directed participants at 12 and 24 months. The odds of 24 month maintenance were 1.37 (95% CI: 0.97-2.03) times greater in the Guided than in the Self-Directed group. When maintenance rates were compared across all follow-ups, there was a consistently higher maintenance rate for Guided participants (HR 1.31, 95% CI: 1.12-1.54). CONCLUSIONS: A sustained, supportive phone- and mail-based intervention promotes weight loss maintenance relative to a brief intervention for participants who have recently lost weight.

Barriers to avoiding fast-food consumption in an environment supportive of unhealthy eating.

OBJECTIVE: To investigate factors (ability, motivation and the environment) that act as barriers to limiting fast-food consumption in women who live in an environment that is supportive of poor eating habits. DESIGN: Cross-sectional study using self-reports of individual-level data and objectively measured environmental data. Multilevel logistic regression was used to assess factors associated with frequency of fast-food consumption. SETTING: Socio-economically disadvantaged areas in metropolitan Melbourne, Australia. SUBJECTS: Women (n 932) from thirty-two socio-economically disadvantaged neighbourhoods living within 3 km of six or more fast-food restaurants. Women were randomly sampled in 2007­2008 as part of baseline data collection for the Resilience for Eating and Activity Despite Inequality (READI) study. RESULTS: Consuming low amounts of fast food was less likely in women with lower perceived ability to shop for and cook healthy foods, lower frequency of family dining, lower family support for healthy eating, more women acquaintances who eat fast food regularly and who lived further from the nearest supermarket. When modelled with the other significant factors, a lower perceived shopping ability, mid levels of family support and living further from the nearest supermarket remained significant. Among those who did not perceive fruits and vegetables to be of high quality, less frequent fast-food consumption was further reduced for those with the lowest confidence in their shopping ability. CONCLUSIONS: Interventions designed to improve women's ability and opportunities to shop for healthy foods may be of value in making those who live in high-risk environments better able to eat healthily.

Roux-en-Y gastric bypass vs intensive medical management for the control of type 2 diabetes, hypertension, and hyperlipidemia: the Diabetes Surgery Study randomized clinical trial.

IMPORTANCE: Controlling glycemia, blood pressure, and cholesterol is important for patients with diabetes. How best to achieve this goal is unknown. OBJECTIVE: To compare Roux-en-Y gastric bypass with lifestyle and intensive medical management to achieve control of comorbid risk factors. DESIGN, SETTING, AND PARTICIPANTS: A 12-month, 2-group unblinded randomized trial at 4 teaching hospitals in the United States and Taiwan involving 120 participants who had a hemoglobin A1c (HbA1c) level of 8.0% or higher, body mass index (BMI) between 30.0 and 39.9, C peptide level of more than 1.0 ng/mL, and type 2 diabetes for at least 6 months. The study began in April 2008. INTERVENTIONS: Lifestyle-intensive medical management intervention and Roux-en-Y gastric bypass surgery. Medications for hyperglycemia, hypertension, and dyslipidemia were prescribed according to protocol and surgical techniques that were standardized. MAIN OUTCOMES AND MEASURES: Composite goal of HbA1c less than 7.0%, low-density lipoprotein cholesterol less than 100 mg/dL, and systolic blood pressure less than 130 mm Hg. RESULTS: All 120 patients received the intensive lifestyle-medical management protocol and 60 were randomly assigned to undergo Roux-en-Y gastric bypass. After 12-months, 28 participants (49%; 95% CI, 36%-63%) in the gastric bypass group and 11 (19%; 95% CI, 10%-32%) in the lifestyle-medical management group achieved the primary end points (odds ratio [OR], 4.8; 95% CI, 1.9-11.7). Participants in the gastric bypass group required 3.0 fewer medications (mean, 1.7 vs 4.8; 95% CI for the difference, 2.3-3.6) and lost 26.1% vs 7.9% of their initial body weigh compared with the lifestyle-medical management group (difference, 17.5%; 95% CI, 14.2%-20.7%). Regression analyses indicated that achieving the composite end point was primarily attributable to weight loss. There were 22 serious adverse events in the gastric bypass group, including 1 cardiovascular event, and 15 in the lifestyle-medical management group. There were 4 perioperative complications and 6 late postoperative complications. The gastric bypass group experienced more nutritional deficiency than the lifestyle-medical management group. CONCLUSIONS AND RELEVANCE: In mild to moderately obese patients with type 2 diabetes, adding gastric bypass surgery to lifestyle and medical management was associated with a greater likelihood of achieving the composite goal. Potential benefits of adding gastric bypass surgery to the best lifestyle and medical management strategies of diabetes must be weighed against the risk of serious adverse events. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00641251.

Bilateral epiphyseal migration following fixation for slipped capital femoral epiphyses in a hypothyroid child.

Progression of slipped capital femoral epiphysis following in situ screw fixation typically occurs through loosening of the screw in the metaphysis. Epiphyseal migration off the screw due to physeal growth is rare. We report epiphyseal migration off bilateral screws in a child undergoing thyroid replacement therapy. Patients with mild and moderate slipped capital femoral epiphysis and endocrine disease should be followed-up with radiographs taken at intervals which reflect the rate of growth. Fixation should be revised if the tip of the screw approaches the physis and initial fixation with two screws may be considered.

Environmental modifications and 2-year measured and self-reported stair-use: a worksite randomized trial.

Environmental modifications have been shown to increase short-term stair use, longer-term success is unclear. This study assessed the 2-year effectiveness of an environmental intervention promoting worksite stair use. We assessed stair use at work by means of self-reports and infrared beam counters (which send a safe and invisible beam of infrared light from one side of a stairwell to a reflector on the other side; when an individual uses the stairs, the infrared beam is disrupted and an instance of stair use is recorded) at six worksites (three intervention, three control) in a group randomized, controlled worksite weight-gain prevention trial in Minneapolis/St. Paul, MN. Intervention modifications were signs encouraging stair use, music, and art posters in stairwells. We collected data before environmental modifications (2006-2007) and at the end of the 2-year intervention (2008-2009). The intervention had a significant positive effect on stair use measured both objectively and via self-report, with greatest increases reported among those participants who used the stairs least at baseline. Following 2-years of continuously-maintained stairwell modifications, increases in both objectively-measured and self-reported stair use were significantly larger at intervention than control worksites. Study findings suggest that the positive impact of environmental modifications on stair use persist over a longer time period than has been previously demonstrated. Results also indicate that infrequent stair users may be most amenable to the behavior changes encouraged by these environmental enhancements.

A theoretically grounded systematic review of material incentives for weight loss: implications for interventions.

BACKGROUND: Providing material incentives for weight loss is a class of intervention strategies that has received considerable attention; however, the effectiveness of this class of strategies is uncertain. Attending to distinctions among incentive strategies may clarify our understanding of prior work and inform the design of future interventions. PURPOSE: A theoretical framework is proposed that distinguishes between four classes of incentive strategies and is used to organize randomized controlled trials of material incentives for weight loss. METHODS: A systematic literature review was conducted. RESULTS: Findings were mixed with regards to the overall efficacy of material incentives for weight loss. Three of the four proposed incentive categories are represented in the literature. Heterogeneous methods were used across studies rendering comparisons between studies difficult. CONCLUSIONS: Definitive conclusions about the usefulness of material incentives for weight loss could not be drawn. A theoretically grounded approach to designing and testing incentive strategies is encouraged.

Lifestyle patterns associated with diet, physical activity, body mass index and amount of recent weight loss in a sample of successful weight losers.

BACKGROUND: Research suggests that the interaction between biological susceptibility and environmental risk is complex and that further study of behavioral typologies related to obesity and associated behaviors is important to further elucidate the nature of obesity risk and how to approach it for intervention. The current investigation aims to identify phenotypical lifestyle patterns that might begin to unify our understanding of obesity and obesity related behaviors. METHODS: Individuals who had recently lost substantial weight of their own initiative completed measures of intentional weight control behaviors and lifestyle behaviors associated with eating. These behaviors were factor analyzed and the resulting factors were examined in relation to BMI, recent weight loss, diet, and physical activity. RESULTS: Four meaningful lifestyle and weight control behavioral factors were identified- regularity of meals, TV related viewing and eating, intentional strategies for weight control, and eating away from home. Greater meal regularity was associated with greater recent weight loss and greater fruit and vegetable intake. Greater TV related viewing and eating was associated with greater BMI and greater fat and sugar intake. More eating away from home was related to greater fat and sugar intake, lower fruit and vegetable intake, and less physical activity. Greater use of weight control strategies was most consistently related to better weight, diet, and physical activity outcomes. CONCLUSIONS: Compared to the individual behavior variables, the identified lifestyle patterns appeared to be more reliably related to diet, physical activity, and weight (both BMI and recent weight loss). These findings add to the growing body of literature identifying behavioral patterns related to obesity and the overall weight control strategy of eating less and exercising more. In future research it will be important to replicate these behavioral factors (over time and in other samples) and to examine how changes in these factors relate to weight loss and weight maintenance over time.

HealthWorks: results of a multi-component group-randomized worksite environmental intervention trial for weight gain prevention.

BACKGROUND: U.S. adults are at unprecedented risk of becoming overweight or obese, and most scientists believe the primary cause is an obesogenic environment. Worksites provide an opportunity to shape the environments of adults to reduce obesity risk. The goal of this group-randomized trial was to implement a four-component environmental intervention at the worksite level to positively influence weight gain among employees over a two-year period. Environmental components focused on food availability and price, physical activity promotion, scale access, and media enhancements. METHODS: Six worksites in a U.S. metropolitan area were recruited and randomized in pairs at the worksite level to either a two-year intervention or a no-contact control. Evaluations at baseline and two years included: 1) measured height and weight; 2) online surveys of individual dietary intake and physical activity behaviors; and 3) detailed worksite environment assessment. RESULTS: Mean participant age was 42.9 years (range 18-75), 62.6% were women, 68.5% were married or cohabiting, 88.6% were white, 2.1% Hispanic. Mean baseline BMI was 28.5 kg/m(2) (range 16.9-61.2 kg/m(2)). A majority of intervention components were successfully implemented. However, there were no differences between sites in the key outcome of weight change over the two-year study period (p = .36). CONCLUSIONS: Body mass was not significantly affected by environmental changes implemented for the trial. Results raise questions about whether environmental change at worksites is sufficient for population weight gain prevention. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00708461.

Financial incentives and weight control.

This paper reviews research studies evaluating the use of financial incentives to promote weight control conducted between 1972 and 2010. It provides an overview of behavioral theories pertaining to incentives and describes empirical studies evaluating specific aspects of incentives. Research on financial incentives and weight control has a history spanning more than 30 years. Early studies were guided by operant learning concepts from Psychology, while more recent studies have relied on economic theory. Both theoretical orientations argue that providing financial rewards for losing weight should motivate people to engage in behaviors that produce weight loss. Empirical research has strongly supported this idea. However, results vary widely due to differences in incentive size and schedule, as well as contextual factors. Thus, many important questions about the use of incentives have not yet been clearly answered. Weight-maintenance studies using financial incentives are particularly sparse, so that their long-term efficacy and thus, value in addressing the public health problem of obesity is unclear. Major obstacles to sustained applications of incentive in weight control are funding sources and acceptance by those who might benefit.

Predictors of nutrition label viewing during food purchase decision making: an eye tracking investigation.

OBJECTIVE: Nutrition label use could help consumers eat healthfully. Despite consumers reporting label use, diets are not very healthful and obesity rates continue to rise. The present study investigated whether self-reported label use matches objectively measured label viewing by monitoring the gaze of individuals viewing labels. DESIGN: The present study monitored adults viewing sixty-four food items on a computer equipped with an eye-tracking camera as they made simulated food purchasing decisions. ANOVA and t tests were used to compare label viewing across various subgroups (e.g. normal weight v. overweight v. obese; married v. unmarried) and also across various types of foods (e.g. snacks v. fruits and vegetables). SETTING: Participants came to the University of Minnesota's Epidemiology Clinical Research Center in spring 2010. SUBJECTS: The 203 participants were ≥18 years old and capable of reading English words on a computer 76 cm (30 in) away. RESULTS: Participants looked longer at labels for 'meal' items like pizza, soup and yoghurt compared with fruits and vegetables, snack items like crackers and nuts, and dessert items like ice cream and cookies. Participants spent longer looking at labels for foods they decided to purchase compared with foods they decided not to purchase. There were few between-group differences in nutrition label viewing across sex, race, age, BMI, marital status, income or educational attainment. CONCLUSIONS: Nutrition label viewing is related to food purchasing, and labels are viewed more when a food's healthfulness is ambiguous. Objectively measuring nutrition label viewing provides new insight into label use by various sociodemographic groups.

Self-weighing frequency is associated with weight gain prevention over 2 years among working adults.

BACKGROUND: Little is known about the association between self-weighing frequency and weight gain prevention, particularly in worksite populations. PURPOSE: The degree to which self-weighing frequency predicted 2-year body weight change in working adults was examined. METHOD: The association between self-weighing frequency (monthly or less, weekly, daily, or more) and 24-month weight change was analyzed in a prospective cohort analysis (n = 1,222) as part of the larger HealthWorks trial. RESULTS: There was a significant interaction between follow-up self-weighing frequency and baseline body mass index. The difference in weight change ranged from -4.4 ± 0.8 kg weight loss among obese daily self-weighers to 2.1 ± 0.4 kg weight gain for participants at a healthy weight who reported monthly self-weighing. CONCLUSION: More frequent self-weighing seemed to be most beneficial for obese individuals. These findings may aid in the refinement of self-weighing frequency recommendations used in the context of weight management interventions.