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Objective: This study aimed to investigate sitting time, the home sedentary environment, and physical activity among weight-loss maintainers in WW (formerly Weight Watchers)., Methods: Participants were 4,305 weight-loss maintainers who had maintained ≥9.1 kg of weight loss (24.7 kg on average) for 3.3 years and had an average current BMI of 27.6 kg/m 2 . A control group of weight-stable individuals with obesity (n = 619) had an average BMI of 38.9 kg/m 2 . The Multicontext Sitting Time Questionnaire and Paffenbarger physical activity questionnaire were administered., Results: Weight-loss maintainers versus controls spent 3 hours less per day sitting during the week (10.9 vs. 13.9; η p 2 = 0.039; P = 0.0001) and weekends (9.7 vs. 12.6; η p 2 = 0.038). Weight-loss maintainers versus controls spent 1 hour less per day in non-work-related sitting using a computer or video games during the week (1.4 vs. 2.3; η p 2 = 0.03; P = 0.0001) and weekends (1.5 vs. 2.5; η p 2 = 0.03; P = 0.0001). Weight-loss maintainers versus controls had similar numbers of sedentary-promoting devices (15.8 vs. 14.8) and expended significantly more calories per week in physical activity (1,835 vs. 785; η p 2 = 0.036; P = 0.0001)., Conclusions: Weight-loss maintainers reported less time sitting than weight-stable individuals with obesity. Future research should test the efficacy of targeting sitting time to help promote long-term weight-loss maintenance., (© 2021 The Obesity Society.)

Physiological adaptations to intentional weight loss can facilitate weight regain. This review summarizes emerging findings on hypothalamic and brainstem circuitry in the regulation of body weight and identifies promising areas for research to improve therapeutic interventions for sustainable weight loss. There is good evidence that body weight is actively regulated in a homeostatic fashion similar to other physiological parameters. However, the defended level of body weight is not fixed but rather depends on environmental conditions and genetic background in an allostatic fashion. In an environment with plenty of easily available energy-dense food and low levels of physical activity, prone individuals develop obesity. In a majority of individuals with obesity, body weight is strongly defended through counterregulatory mechanisms, such as hunger and hypometabolism, making weight loss challenging. Among the options for treatment or prevention of obesity, those directly changing the defended body weight would appear to be the most effective ones. There is strong evidence that the mediobasal hypothalamus is a master sensor of the metabolic state and an integrator of effector actions responsible for the defense of adequate body weight. However, other brain areas, such as the brainstem and limbic system, are also increasingly implicated in body weight defense mechanisms and may thus be additional targets for successful therapies., (© 2021 The Obesity Society.)

Objective: This study aimed to investigate the roles of frequency and consistency of self-weighing in promoting weight-loss maintenance., Methods: Participants were 74 adults who completed a 3-month internet-based weight-loss program followed by a 9-month no-intervention maintenance period. Frequency of self-weighing was defined as the number of days that participants self-weighed during the maintenance period via a study-provided smart scale. Consistency was defined as the number of weeks that participants self-weighed at a certain frequency, with multiple minimum thresholds examined. Hierarchical regression analyses were used to assess associations among frequency, consistency, and weight change during the maintenance period., Results: Greater consistency was significantly associated with less weight regain when defined as the number of weeks that participants self-weighed on ≥6 d/wk or 7 d/wk (P values < 0.05). Contrary to hypotheses, frequency was not associated with weight change (P = 0.141), and there was not a significant interaction between frequency and consistency., Conclusions: Results demonstrate that consistency of self-weighing may be more important than total frequency for preventing weight regain after the end of a weight-loss program. Further, results suggest that a high level of consistency (self-weighing for ≥6 d/wk or 7 d/wk) may be necessary to promote successful weight-loss maintenance., (© 2020 The Obesity Society.)

Objective: This study aimed to compare two energy-restricted, nutrient-dense diets at the upper or lower ends of the dietary fat recommendation range (lower fat [20% energy from fat] versus moderate fat [35%]) on weight loss using behavioral theory-based nutrition education., Methods: A total of 101 premenopausal women with overweight or obesity were randomized to an energy-restricted lower-fat or moderate-fat diet for 1 year. Interventions included 28 behavioral theory-based nutrition education sessions plus weekly exercise sessions., Results: Both treatment groups experienced weight loss (-5.0 kg for lower fat and -4.3 kg for moderate fat; P < 0.0001), but there was no difference in weight loss or fat intake between groups. Total and low-density lipoprotein cholesterol decreased (-3. 4 mg/dL and -3.8 mg/dL; P < 0.05), and high-density lipoprotein cholesterol increased (1.9 mg/dL; P < 0.05) in both groups at 12 months. Diet quality, assessed by the Healthy Eating Index, increased significantly at 4 months versus baseline (70.8 [0.9] vs. 77.8 [1.0]) and was maintained through 12 months. Higher Healthy Eating Index scores were associated with greater weight loss at 4 months (r = -0.2; P < 0.05)., Conclusions: In the context of a well-resourced, free-living weight-loss intervention, total fat intake did not change; however, theory-based nutrition education underpinned by food-based recommendations resulted in caloric deficits, improvements in diet quality, and weight loss that was sustained for 1 year., (© 2020 The Authors. Obesity published by Wiley Periodicals LLC on behalf of The Obesity Society (TOS).)

Objective: The study's purpose was to use validated questionnaires to identify novel behavioral and psychological strategies among weight loss maintainers (WLMs) in a commercial weight management program., Methods: Participants were 4,786 WLMs in WW (formerly Weight Watchers, New York, New York) who had maintained weight loss  ≥ 9.1 kg (24.7 kg/23.8% weight loss on average) for 3.3 years and had a current mean BMI of 27.6 kg/m 2 . A control group of 528 weight-stable individuals with obesity had a mean BMI of 38.9 kg/m 2 and weight change  < 2.3 kg over the previous 5 years., Results: WLMs versus Controls practiced more frequent healthy dietary choices (3.3 vs. 1.9; η p 2  = 0.37), self-monitoring (2.6 vs. 0.7; η p 2  = 0.30), and psychological coping (2.5 vs. 1.1; η p 2  = 0.25) strategies. WLMs also reported more willingness to ignore food cravings (4.4 vs. 3.5; η p 2  = 0.16) and had greater habit strength for healthy eating (5.3 vs. 3.2;  η p 2  = 0.21). Standard canonical coefficients indicated that dietary (0.52), self-monitoring (0.40), and psychological (0.14) strategies as well as habit strength for healthy eating (0.15) contributed independently and most (49.5% of variance) to discriminating groups., Conclusions: In a widely available weight management program, more frequent practice of healthy dietary, self-monitoring, and psychological coping strategies as well as development of greater habit strength for healthy eating differentiated long-term WLMs from weight-stable individuals with obesity., (© 2020 California Polytechnic State University. Obesity published by Wiley Periodicals, Inc. on behalf of The Obesity Society (TOS).)

Objective: The study objective was to determine whether two self-regulation interventions that reduced 3-year weight gain in young adults remain effective at 6 years., Methods: A randomized trial was conducted in two academic settings in 599 young adults, aged 18 to 35 years, with normal weight or overweight; 504 (84%) reconsented for a 6-year extension (Study of Novel Approaches to Weight Gain Prevention-Extended [SNAP-E]) with ongoing intervention and assessments. Weight gain over 6 years was compared for all assigned to Control, Large Changes (LC; lose 5-10 pounds initially), and Small Changes (SC; make small daily changes in intake and activity)., Results: Weight change from baseline to 6 years did not differ significantly among the three groups (Control = 3.9 kg, SC = 4.1 kg, and LC = 2.8 kg). However, there was a significant age-by-treatment interaction (P = 0.002). Among those < 25 years old, weight gain from baseline to 6 years averaged 7.3 kg in the Control group and was reduced by almost 50% in LC and SC. LC also significantly reduced mean weight gain (area under the curve) over 6 years compared with Control or SC., Conclusions: Although the interventions did not reduce weight gain at 6 years for the full cohort, they were effective in those < 25 years old. Future efforts should focus on young adults aged 18 to 24.9 and test more intensive interventions with more diverse participants., (© 2019 The Obesity Society.)

Objective: The goal of the present study was to deconstruct the 17 treatment arms used in the Early Adult Reduction of weight through LifestYle (EARLY) weight management trials., Methods: Intervention materials were coded to reflect behavioral domains and behavior change techniques (BCTs) within those domains planned for each treatment arm. The analytical hierarchy process was employed to determine an emphasis profile of domains in each intervention., Results: The intervention arms used BCTs from all of the 16 domains, with an average of 29.3 BCTs per intervention arm. All 12 of the interventions included BCTs from the six domains of Goals and Planning, Feedback and Monitoring, Social Support, Shaping Knowledge, Natural Consequences, and Comparison of Outcomes; 11 of the 12 interventions shared 15 BCTs in common across those six domains., Conclusions: Weight management interventions are complex. The shared set of BCTs used in the EARLY trials may represent a core intervention that could be studied to determine the required emphases of BCTs and whether additional BCTs add to or detract from efficacy. Deconstructing interventions will aid in reproducibility and understanding of active ingredients., (© 2019 The Obesity Society.)

Objective: Greater frequency of self-weighing has been associated with greater weight loss in weight management interventions, but little is known regarding the accuracy of self-reported weight data., Methods: Agreement between objective smart-scale and self-reported weight data was assessed in 74 adults (age = 50.7 years; BMI = 31.2 kg/m 2 ) enrolled in a 12-week, Internet-based weight management program. Participants were asked to self-weight daily using a study-provided smart scale and to self-report weights via the study website., Results: There was strong agreement between smart-scale and self-reported weight values (intraclass correlation = 0.982) but only moderate agreement regarding frequency of self-weighing assessed via each method (κ = 0.491; P < 0.0001). Greater self-weighing frequency was associated with greater weight loss across measures (all P < 0.001). Compared with days when participants did both, weights were 0.66 kg higher on days when participants self-weighed via the smart scale but did not self-report weight (8% of days) and 0.58 kg higher on days when they self-reported weight but did not self-weigh via the smart scale (4% of days; all P < 0.0001)., Conclusions: Results suggest that self-reported weight values are similar to smart-scale measurements; however, either method alone may underestimate self-weighing frequency. Furthermore, missing self-weighing data should not be treated as ignorable because weights may be higher than those observed on nonmissing days., (© 2019 The Obesity Society.)

Objective: This study aimed to examine whether 1-month BMI improvement is predictive of superior 6- and 12-month BMI changes in a national sample of youth in pediatric weight management treatment., Methods: Participants were 4- to 18-year-olds from the Pediatric Obesity Weight Evaluation Registry, a prospective study collecting data from 31 pediatric weight management programs across the United States. Response at 1 month was defined as ≥ 3% BMI reduction; success at 6 and 12 months was defined as ≥ 5% BMI reduction from baseline. Analyses used linear and logistic regression with robust variance estimation., Results: Primary analyses were completed with 687 participants (mean age 12.2 years). One-month responders demonstrated significant improvements in BMI compared with nonresponders at 6 months (BMI, -2.05 vs. 0.05; %BMI, -5.81 vs. 0.23; P < 0.001 for all) and 12 months (BMI, -1.87 vs. 0.30; %BMI, -5.04 vs. 1.06; P < 0.001 for all). The odds of success for 1-month responders were 9.64 (95% CI: 5.85-15.87; P < 0.001) times that of nonresponders at 6 months and 5.24 (95% CI: 2.49-11.02; P < 0.001) times that of nonresponders at 12 months., Conclusions: In treatment-seeking youth with obesity, early BMI reduction was significantly associated with greater long-term BMI reduction. Nonresponders may benefit from early treatment redirection or intensification., (© 2019 The Obesity Society.)

Objective: Weight loss maintenance is one of the biggest challenges in behavioral weight loss programs. The present study aimed to examine metabolic influences on the mesolimbic reward system in people with successful and unsuccessful long-term weight loss maintenance., Methods: Thirty-three women with obesity at least 6 months after the completion of a diet were recruited: seventeen women were able to maintain their weight loss, whereas sixteen showed weight regain. Using functional magnetic resonance imaging in combination with the assessment of appetite-regulating hormones, neural reward processing during hunger and satiety was investigated. An incentive delay task was employed to investigate the expectation and receipt of both food-related and monetary reward., Results: Only participants with successful weight loss maintenance showed a satiety-induced attenuation of brain activation during the receipt of a food-related reward. Furthermore, in successful weight loss maintenance, the attenuation of active ghrelin levels was related to brain activation in response to food-related reward anticipation during satiety., Conclusions: The findings suggest that an attenuated influence of satiety signaling on the neural processing of food-related reward contributes to unsuccessful weight loss maintenance. Thus, intact satiety signaling to the mesolimbic reward system may serve as a promising target for tackling weight cycling., (© 2018 The Obesity Society.)

Objective: The objective of this review was to critically review findings from recent studies evaluating the effects of nonnutritive sweeteners (NNSs) on metabolism, weight, and obesity-related chronic diseases. Biologic mechanisms that may explain NNS effects will also be addressed., Methods: A comprehensive review of the relevant scientific literature was conducted., Results: Most cross-sectional and prospective cohort studies report positive associations between NNS consumption, body weight, and health conditions, including type 2 diabetes, cardiovascular disease, and nonalcoholic fatty liver disease. Although findings in cellular and rodent models suggest that NNSs have harmful effects on metabolic health, most randomized controlled trials in humans demonstrate marginal benefits of NNS use on body weight, with little data available on other metabolic outcomes., Conclusions: NNS consumption is associated with higher body weight and metabolic disease in observational studies. In contrast, randomized controlled trials demonstrate that NNSs may support weight loss, particularly when used alongside behavioral weight loss support. Additional long-term, well-controlled intervention studies in humans are needed to determine the effects of NNSs on weight, adiposity, and chronic disease under free-living conditions., (Published 2018. This article is a U.S. Government work and is in the public domain in the USA.)

Objective: Risk for obesity is determined by a complex mix of genetics and lifetime exposures at multiple levels, from the metabolic milieu to psychosocial and environmental influences. These phenotypic differences underlie the variability in risk for obesity and response to weight management interventions, including differences in physical activity and sedentary behavior., Methods: As part of a broader effort focused on behavioral and psychological phenotyping in obesity research, the National Institutes of Health convened a multidisciplinary workshop to explore the state of the science in behavioral and psychological phenotyping in humans to explain individual differences in physical activity, both as a risk factor for obesity development and in response to activity-enhancing interventions., Results: Understanding the behavioral and psychological phenotypes that contribute to differences in physical activity and sedentary behavior could allow for improved treatment matching and inform new targets for tailored, innovative, and effective weight management interventions., Conclusions: This summary provides the rationale for identifying psychological and behavioral phenotypes relevant to physical activity and identifies opportunities for future research to better understand, define, measure, and validate putative phenotypic factors and characterize emerging phenotypes that are empirically associated with initiation of physical activity, response to intervention, and sustained changes in physical activity., (© 2017 The Obesity Society.)

Objective: Sufficient sleep is required for weight maintenance. Sleep deprivation due to noise exposure stimulates weight gain by increasing hyperphagia and reducing energy expenditure (EE). Yet the mechanistic basis underlying the weight gain response is unclear. Orexin-A promotes arousal and negative energy balance, and orexin terminals project to the ventrolateral preoptic area (VLPO), which is involved in sleep-to-wake transitions. To determine whether sleep deprivation reduces orexin function in VLPO and to test the hypothesis that sleep deprivation would attenuate the orexin-A-stimulated increase in arousal, physical activity (PA), and EE., Methods: Electroencephalogram, electromyogram, distance traveled, and EE were determined in male Sprague-Dawley rats following orexin-A injections into VLPO both before and after acute (12-h) and chronic (8 h/d, 9 d) sleep deprivation by noise exposure., Results: Orexin-A in the VLPO significantly increased arousal, PA, total EE, and PA-related EE and reduced sleep and respiratory quotient before sleep deprivation. In contrast to after acute sleep deprivation in which orexin-A failed to stimulate EE during PA only, orexin-A failed to significantly increase arousal, PA, fat oxidation, total EE, and PA-related EE after chronic sleep deprivation., Conclusions: Sleep deprivation may reduce sensitivity to endogenous stimuli that enhance EE due to PA and thus stimulate weight gain., (© 2017 The Obesity Society.)