Fat chance for physical activity

There is a huge variation in weight loss outcomes between bariatric patients, possibly due to differences in caloric intake and changes in the amount physical activity. However, the association between the change in energy intake and weight loss has not yet been the subject of an extensive investigation. To explore the relationship between total energy intake and % total body weight loss (%TBWL) over a period of 4years post-surgery. Of the 466 patients who were asked to participate, a total 135 patients were included in this study. They all underwent bariatric surgery, 54 with primary Roux-en-Y Gastric Bypass, 43 redo Roux-en-Y gastric bypass after laparoscopic gastric banding and 38 laparoscopic sleeve gastrectomy. Pre- and post-operative dietary intake and physical activity were collected for both a weekday and a weekend day. The main analysis was performed using multiple regression analyses and was adjusted for age at surgery, BMI at baseline, obstructive sleep apnoea syndrome, type of eating behaviour, change in physical activity and protein intake (g/kg body weight). %TBWL over time, post-operative energy intake and change in physical activity did not differ between the different procedure groups (p = 0.312, p = 0.988 and p = 0.050, respectively). Change in energy intake did differ between different procedure groups (p = 0.031) and linear regression showed that this was related to total body weight loss for the fully adjusted model (β = - 0.004, p = 0.014). This study showed a higher decrease in energy intake to be related with a higher %TBWL.

Child Obesity Can Be Reduced With Vigorous Activity Rather Than Restriction of Energy Intake

Can health promotion at the workplace help prevent cancer?

Evidence-based online behavioral weight loss (BWL) treatment targets a combination of diet, physical activity, and behavioral skills training. While weight loss outcomes are well documented, little is known about changes in physical activity. This study examined changes in objectively measured physical activity across the energy expenditure spectrum during a fully automated, online BWL program. Adults with overweight or obesity (n = 63) completed a 12-week, online BWL program. Participants wore an accelerometer for 7days and body weight was measured in-clinic at pre- and post-treatment. At post-treatment, mean daily moderate-to-vigorous physical activity increased by about 4min (SE = 1.59, p = 0.01). There were no statistically significant changes in light physical activity or time spent sedentary (p's > 0.05). Despite only minimal changes in moderate-to-vigorous physical activity overall, larger increases correlated with greater weight loss (r = - 0.28, p = 0.02), which averaged 6.1% of baseline weight at post-treatment. Though achieving important weight loss outcomes, online programs may fail to produce clinically relevant improvements in physical activity, which can put weight loss maintenance at risk.

Evaluate the effect of an after-school intervention on physical activity program changes and individual behaviors among children. A quasi-experimental evaluation of a YMCA-driven environmental change intervention with 16 intervention and 16 control sites in four metropolitan areas in the United States. Intervention sites participated in learning collaboratives designed to promote physical activity and nutrition through environmental change, educational activities, and parent engagement. Behavioral foci included increasing overall physical activity levels as well as combined moderate and vigorous physical activity and vigorous physical activity. Outcomes were assessed longitudinally using preintervention and follow-up surveys of program implementation and accelerometer measures of physical activity. ActiGraph accelerometer data were collected from a sample of 212 children, ages 5-11 yr, attending the programs. On average, 3 d of data were gathered per child. Reliability of the accelerometer counts averaged 0.78. Multivariate regression models were used to control for potential confounding variables and to account for clustering of observations. Data indicate greater physical activity increases in children in intervention versus control sites after modest intervention implementation. Controlling for baseline covariates, children in intervention sites showed greater increases in average physical activity level than in control sites (76 counts per minute, P = 0.037, 95% confidence interval (CI) = 8.1-144) and more minutes of moderate and vigorous physical activity (10.5 min·d(-1), P = 0.017, 95% CI = 1.5-18.6), minutes of moderate physical activity (5.6 min·d(-1), P = 0.020, 95% CI = 0.99-10.2), and minutes of vigorous physical activity (5.1 min·d(-1), P = 0.051, 95% CI = 0.21-9.93). Results indicate significant increases in daily physical activity among children in intervention versus control sites. This study documents the effectiveness of an environmental change approach in an applied setting.

The objective of this study was to identify mechanisms through which valproic acid (VPA) causes weight gain. Healthy participants (N = 52) were randomized to VPA or placebo in a double-blind study. Energy intake (EI) was measured in the laboratory at lunch and dinner, and physical activity (PA) was measured with accelerometry. Glucose levels and hormones [Peptide YY(3-36), glucagon-like peptide-1 (GLP-1), leptin, ghrelin, insulin] that regulate EI were measured. Assessments occurred at baseline and week 3. Change from baseline was evaluated with mixed models (alpha = 0.05). Weight significantly increased in the VPA group (+0.49 kg), but not the placebo group. The VPA group increased fast food fats cravings and decreased glucose levels compared with placebo. Change in weight, EI and PA did not differ by group. Within group analyses indicated that the VPA group increased PA, hunger, binge eating, depression and GLP-1. VPA-associated weight gain is not likely due to changes in PA or the gut hormones studied. Although EI did not increase when measured after 3 weeks of treatment, VPA decreased glucose levels and increased motivation to eat; hence, EI might have increased in the short-term. Research testing VPA on short-term (1 week) EI, metabolism, and substrate partitioning is warranted.

Review Question/Objective The primary objective of this review is to identify the effectiveness of web-based interventions on weight loss and maintenance. The second objective is to identify the effectiveness of web-based interventions on behaviours associated with weight loss (eating and physical activity). The third objective is to identify what components of web-based interventions are associated with greater weight loss and maintenance, as well as lower attrition rates. Criteria for Inclusion Types of participants The quantitative component of this review will consider studies that include overweight and/or obese adults, aged greater than 18 years. Overweight and obesity will be defined as a body mass index (BMI) greater than or equal to 25(kg/m2). Types of intervention(s) The quantitative component of the review will consider studies that evaluate web-based interventions with the primary aim of achieving weight loss or weight maintenance following weight loss. This includes studies with the aim of achieving positive dietary and physical activity behaviour change for participants that include overweight/obesity outcome measures. However, if the stated aim is to achieve positive dietary and physical activity behaviour change for participants, and they do not include overweight/obesity outcome measures they will be excluded. At least one arm of the study must include a web-based intervention. A web-based intervention will be based around a website that participants receive information from and directly interface with. They are not required to input information into the website for the intervention to be included. Types of outcomes This review will consider studies that include the following outcome measures: Primary Outcome: Overweight/obesity related outcomes: weight (kg), % body weight lost, BMI, waist measurements, % body fat, % lost 5% of body weight. Secondary Outcomes: Dietary behaviours: energy intake, core food group intake (e.g. number of serves of fruit per day), macronutrient composition of diet (e.g. fat intake per day) Physical activity behaviours: energy expenditure, time spent in activity, steps per day. Effect modifiers/confounders: Compliance/engagement with website: website logins, completion of self-monitoring diaries, attendance at meetings/group discussions, retention etc Adjuncts to web-based intervention (e.g. contact with professional/face to face contact, other eHealth technology such as SMS, email, CD-Rom, Personal Digital Assistant (PDA) and use of rewards/prizes) Intervention based on theoretical models Intensity of web-based intervention: type and number of features included (e.g. self-monitoring diary, chat room, discussion board)

ObjectiveBariatric surgery remains the most effective treatment to achieve substantial weight loss; however, total daily energy expenditure and physical activity changes in response to such interventions have been seldom explored.MethodsIn this prospective observational study, total daily energy expenditure (TDEE) using doubly labeled water and physical activity (SenseWear armband) was assessed in 17 females (mean±SD: 48.6±9.7 kg/m2, 43±12 years) at baseline and 8 and 52 weeks following either bariatric surgery (BSG, N=9) or a low-calorie diet (LCD, N=8). Energy intake was assessed using the intake-balance method.ResultsAfter 8 weeks, weight loss was 16.0±3.5 kg and TDEE decreased by 552±319 kcal/d in BSG (P<0.001) compared to 8.8±3.4 kg and 256±239 kcal/d in LCD (P<0.05). After 52 weeks, weight loss was 44.3±16.4 kg and TDEE decreased by 583±418 kcal/d (P<0.001), compared to 4.3±6.7 kg and 84±285 kcal/d in LCD (P>0.05). TDEE was lower than predicted in BSG at 8 (P=0.03) but not 52 weeks (P=0.77). There was no evidence of metabolic adaptation in LCD. Average daily energy intake in BSG was 1403 ± 245 kcal/d compared to 2545 ± 398 kcal/d in LCD (P<0.001). In BSG, step count and physical activity minutes were increased at 52 weeks compared to baseline (P=0.03), whereas no significant changes were observed in LCD.ConclusionBariatric surgery-induced weight loss decreased TDEE at 8 weeks and 1 year, resulting in metabolic adaptation after 8 weeks that was reversed at 1 year. These changes were accompanied by an increase in physical activity.

Our objective was to gain insight in the calculation and interpretation of population health metrics that inform disease prevention. Using as model environmental exposure to lead (ELE), a global pollutant, we assessed population health metrics derived from the Third National Health and Nutrition Examination Survey (1988 to 1994), the GBD (Global Burden of Disease Study 2010), and the Organization for Economic Co-operation and Development. In the National Health and Nutrition Examination Survey, the hazard ratio relating mortality over 19.3 years of follow-up to a blood lead increase at baseline from 1.0 to 6.7 µg/dL (10th–90th percentile interval) was 1.37 (95% CI, 1.17–1.60). The population-attributable fraction of blood lead was 18.0% (10.9%–26.1%). The number of preventable ELE-related deaths in the United States would be 412 000 per year (250 000–598 000). In GBD 2010, deaths and disability-adjusted life-years globally lost due to ELE were 0.67 million (0.58–0.78 million) and 0.56% (0.47%–0.66%), respectively. According to the 2017 Organization for Economic Co-operation and Development statistics, ELE-related welfare costs were $1 676 224 million worldwide. Extrapolations from the foregoing metrics assumed causality and reversibility of the association between mortality and blood lead, which at present-day ELE levels in developed nations is not established. Other issues limiting the interpretation of ELE-related population health metrics are the inflation of relative risk based on outdated blood lead levels, not differentiating relative from absolute risk, clustering of risk factors and exposures within individuals, residual confounding, and disregarding noncardiovascular disease and immigration in national ELE-associated welfare estimates. In conclusion, this review highlights the importance of critical thinking in translating population health metrics into cost-effective preventive strategies.

Investigating the effects of behavioral change, social support, and self-efficacy in physical activity in a collectivistic culture: Application of Stages of Motivational Readiness for Change in Korean young adults

BackgroundLow cardiorespiratory fitness is strongly associated with cardiovascular diseases and mortality. Although increased physical activity can improve cardiorespiratory fitness, this relationship has not been examined in a large bariatric population undergoing perioperative care focusing on long-term lifestyle change.ObjectivesTo evaluate changes in physical activity, weight loss, and cardiorespiratory fitness up to 24 months after bariatric surgery, and to evaluate the relationships of change in physical activity with weight loss and change in cardiorespiratory fitness.Materials and MethodsFour thousand seven hundred eighty-five patients who underwent primary Roux-en-Y gastric bypass or sleeve gastrectomy between January 2012 and December 2014 were included. Physical activity was assessed by the Baecke questionnaire (work, leisure, and sport activity) and cardiorespiratory fitness, defined as VO2max relative to fat-free mass (VO2max/FFM), was assessed by the Åstrand test.ResultsTwenty-four months postoperative, significant improvements were seen in sport and leisure activity assessments (n = 3548, P < 0.001), weight loss (n = 3695, P < 0.001), and VO2max/FFM (n = 1852, P < 0.001). Furthermore, regression analysis showed that change in leisure activity was positively associated with weight loss (n = 3535, ß = 1.352, P < 0.001) and change in sport activity was positively associated with change in VO2max/FFM (n = 1743, ß = 1.730, P < 0.001).ConclusionBariatric surgery complemented by a comprehensive bariatric care program can lead to improvement in physical activity, as well as weight loss and improvement in cardiorespiratory fitness. The positive associations of change in leisure activity with weight loss and change in sport activity with cardiorespiratory fitness suggest that bariatric care programs can enhance postoperative outcomes by improving the patient’s physical activity.

Background Physical inactivity and mid-life obesity are modifiable risk factors for frailty. However, declines in physical activity and weight loss may co-occur in the years preceding the onset of frailty. It is undetermined whether monitoring concurrent changes in physical activity and body weight can improve the early detection of frailty and to what extent their relationship is influenced by reverse causation. Methods We examined the longitudinal changes in physical activity and body weight over 8 years and the incidence of frailty over a median follow-up of 8 years among 5,759 community-dwelling older adults from the nationally representative Health and Retirement Study (US). We further assessed physical activity and BMI measured at different years (0, 2, 4, 6, and 8 years, respectively) preceding frailty assessment. Findings A total of 1293 incident frailty cases were documented. Decreased physical activity (adjusted hazard ratio [HR]:1.22; 95% CI, 1.06-1.39) and weight loss (HR = 1.20; 95% CI, 1.05-1.37) were independently associated with increased frailty risk after adjusting for initial physical activity and BMI and other covariates, with the highest risk observed in individuals experiencing both. The association between lower physical activity and increased risk of frailty appeared more pronounced when physical activity was assessed closer to frailty diagnosis, whereas the association between obesity and frailty was attenuated. Discussion Tracking changes in physical activity and body weight may be an easy and effective approach to help identify high-risk individuals for timely frailty intervention. Reverse causation may impact association estimates and causal interpretations even in non-frail older adults.

In this secondary analysis of the DiOGenes study, we investigated whether physical activity (PA) contributes to diet-induced weight loss and helps to reduce subsequent regain. We also studied the associations of PA with changes in cardiometabolic variables. Adults with overweight were included and followed an 8-week low-calorie diet (LCD). When successful (>8% weight loss), participants were randomized to different ad libitum diet groups and were advised to maintain their weight loss over the 6-month intervention period. Body weight (BW), body composition, cardiometabolic variables and subjectively-assessed PA were measured at baseline, at the end of weight loss and at the end of the intervention. BW was reduced by the LCD (from 99.8 ± 16.7 to 88.4 ± 14.9 kg; P < 0.001). This reduction was maintained during the weight maintenance period (89.2 ± 16.0 kg). Total PA (sum score of the three subscales of the Baecke questionnaire) increased during the weight loss period (from 8.16 ± 0.83 to 8.39 ± 0.78; P < 0.001) and this increase was subsequently maintained (8.42 ± 0.90). We found no evidence that baseline PA predicted weight loss. However, a higher level of baseline PA predicted a larger weight-loss-induced improvement in total cholesterol, triglycerides, glucose and CRP, and in post-prandial insulin sensitivity (Matsuda index). Subsequent weight and fat mass maintenance were predicted by the post-weight loss level of PA and associated with changes in PA during the weight maintenance phase. In conclusion, despite the fact that higher baseline levels of PA did not predict more weight loss during the LCD, nor that an increase in PA during the LCD was associated with more weight loss, higher PA levels were associated with more improvements in several cardiometabolic variables. The positive effect of higher PA on weight loss maintenance seems in contrast to randomized controlled trials that have not been able to confirm a positive effect of exercise training programmes on weight loss maintenance. This analysis supports the notion that higher self-imposed levels of PA may improve the cardiometabolic risk profile during weight loss and help to maintain weight loss afterwards.

Direct measurement of physical activity may be critical to revealing its relationship with the change in fat mass over time. The aim of this study was to determine the relationship between accelerometer-determined change in physical activity and change in fat mass in severely obese men and women. A total of 49 severely obese men (n = 12) and women (n = 37) (mean age 42.8 years (standard deviation (SD) 9.6); mean body mass index 42.0 kg/m2 (SD 5.9) participated in a 1-year lifestyle intervention with 4 measurements of physical activity (Actigraph GT1M accelerometer), energy intake (180-item food frequency questionnaire), and body composition. Associations were determined using linear regression analyses. In the total group change in both duration and intensity of physical activity were independently related to change in fat mass (partial r = -0.38 to -0.31, p = 0.001-0.007) after adjustment for baseline body weight, gender and change in energy intake. A gender-specific effect of change in physical activity duration was found for change in fat mass (p for change in physical activity duration*gender < 0.001), where the association was significant in men (partial r = -0.53, p < 0.001), but not in women (partial r = -0.17, p = 0.149). Increased intensity of physical activity was associated with loss of fat mass in severely obese men and women, whereas physical activity duration was associated with fat mass loss in men.

Recently developed accelerometer devices have been used in large epidemiological studies for continuous and objective monitoring of physical activities. Typically, physical movements are summarized as minutes in light, moderate, and vigorous physical activities in each wearing day. Because of preponderance of zeros, zero-inflated distributions have been used for modeling the daily moderate or higher levels of physical activity. Yet, these models do not fully account for variations in daily physical activity and cannot be extended to model weekly physical activity explicitly, while the weekly physical activity is considered as an indicator for a subject's average level of physical activity. To overcome these limitations, we propose to use a zero-inflated Poisson mixture distribution that can model daily and weekly physical activity in same family of mixture distributions. Under this method, the likelihood of an inactive day and the amount of exercise in an active day are simultaneously modeled by a joint random effects model to incorporate heterogeneity across participants. If needed, the method has the flexibility to include an additional random effect to address extra variations in daily physical activity. Maximum likelihood estimation can be obtained through Gaussian quadrature technique, which is implemented conveniently in an R package GLMMadaptive. Method performances are examined using simulation studies. The method is applied to data from the Hispanic Community Health Study/Study of Latinos to examine the relationship between physical activity and BMI groups and within a participant the difference in physical activity between weekends and weekdays.