Patterns of physical activity and sedentary behavior in normal-weight, overweight and obese adults, as measured with a portable armband device and an electronic diary

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.

Smartphone-based educational and counseling interventions for women with high body mass index at Urmia's health centers

BACKGROUND AND PURPOSE

Overweight and obesity in women of reproductive age not only contribute to chronic diseases but also lead to fertility issues, adverse pregnancy outcomes, and psychological challenges. Among the detrimental behaviors associated with obesity, the consumption of fast foods and sedentary lifestyles have the most significant impact on weight gain and require effective interventions. This study aims to examine the effectiveness of an educational and counseling smartphone intervention in raising awareness and modifying behaviors related to sedentary behavior and fast food consumption in women with high body mass index.

MATERIALS AND METHODS

This randomized controlled trial was conducted with two parallel groups comprising 106 women of reproductive age who sought assistance at Urmia health centers in 2022. Participants with diverse social and economic backgrounds were included. They were randomly assigned to either a control group or an intervention group. Valid and reliable questionnaires were administered to assess awareness regarding sedentary behaviors and fast foods consumption, as well as engagement in sedentary behaviors and consumption of fast foods. In addition to standard care, the intervention group received educational and counseling sessions through a dedicated smartphone application. Data analysis was performed using SPSS 20 software at a significance level of P < 0.05.

FINDINGS

The results of a statistical t-test indicated a noteworthy disparity between the control and intervention groups concerning the average awareness scores related to fast foods consumption (P < 0.001) and sedentary behaviors (P < 0.001) before and 3 months after the intervention. Additionally, a substantial statistical difference was observed in the mean consumption of fast foods (P < 0.001) and hours of sedentary behaviors (P < 0.001) before and 3 months after the intervention when comparing the two groups.

CONCLUSION

Educational and counseling programs, when applied effectively, can serve the dual purpose of enhancing awareness concerning sedentary behaviors and fast foods consumption while concurrently fostering a reduction in the prevalence of these behaviors. The study was registered in the Iranian Registry of Clinical Trials (IRCT Id: IRCT20210722051953N1) at 04/08/2021.

Metabolic adaptation is associated with a greater increase in appetite following weight loss: a longitudinal study

BACKGROUND

Weight loss is associated with a disproportionate reduction in energy expenditure, along with increases in hunger feelings and ghrelin concentrations. These changes are presumed to be homeostatic mechanisms to counteract the energy deficit. The possibility that these 2 components of the energy balance equation are mechanistically linked has never been examined.

OBJECTIVE

This study aimed to determine if the disproportionate reduction in resting metabolic rate (RMR) seen with weight loss is associated with changes in the plasma concentration of gastrointestinal hormones involved in appetite regulation and subjective appetite ratings.

METHODS

This was a longitudinal study with repeated measurements. Fifty-six individuals with obesity (body mass index [BMI]: 34.5±0.5 kg/m2; age: 47±1 y; 26 males) underwent an 8 wk low-energy diet, followed by 4 wk of refeeding and weight stabilization. The RMR, respiratory quotient (RQ), body composition, plasma concentrations of ghrelin, glucagon-like peptide 1, peptide YY, cholecystokinin, insulin, and appetite ratings in the fasting and postprandial states were measured at baseline, Wk9 and 13. Metabolic adaptation was defined as significantly lower when measured versus the predicted RMR (pRMR) (from own regression model using baseline data).

RESULTS

A 14.2±0.6 kg weight loss was seen at Wk9 and maintained at Wk13. RQ was significantly reduced at Wk9 (0.82±0.06 vs. 0.76±0.05, P< 0.001) but returned to baseline at Wk13. Metabolic adaptation was seen at Wk9, but not Wk13 (-341±58, P <0.001 and -75±72 kJ/d, P = 0.305, respectively). The larger the difference between measured and predicted RMR at both timepoints, the greater the increase in hunger, desire to eat, and composite appetite score (fasting and postprandial at Wk9, postprandial only at Wk13), even after adjusting for weight loss and RQ.

CONCLUSION

A larger metabolic adaptation during weight loss is accompanied by a greater drive to eat. This might help explain the interindividual differences in weight loss outcomes to dietary interventions.

Correlates of physical activity and sedentary behavior in adults living with overweight and obesity: A systematic review

Overweight and obesity are consistently associated with lower physical activity (PA) levels and greater sedentary behavior (SB) in population studies. To date, no review has evaluated the factors associated with these behaviors in the specific population who have developed obesity/overweight. The aim of this systematic review was to identify the correlates/determinants of SB and PA in adults with overweight and obesity. Five databases were searched for studies, which reported factors or outcomes relating to PA or SB in adults living with overweight/obesity, published from 1980 to 2021. The factors were categorized using a socioecological model, strength, and direction of association. Of 34,058 articles retrieved, 45 studies were included, and 155 factors were identified. Self-efficacy, intrinsic motivation, exercise enjoyment, self-perceived good health, and social support were consistently associated with higher levels of PA. Consistent negative correlations were married females, increased BMI, obesity severity, pain, number of comorbidities, lack of time, energy, and willpower, and hilly terrain. Few studies (n = 12) examined SB, and no evidence for consistent associations were found. This review identified several correlates specific to PA in this population. Further studies are required to identify directionality and distal correlates for PA and all correlate levels of SB.

Vigorous-intensity exercise as a modulator of cardiac adipose tissue in women with obesity: a cross-sectional and randomized pilot study

Cardiac adipose tissue (CAT) has become an important target for the reduction of disease risk. Supervised exercise programs have shown potential to "significantly" reduce CAT; however, the impact of different exercise modalities is not clear, and the relationships between CAT, physical activity (PA) levels and fitness (PFit) remain unknown. Therefore, the purpose of this study was to analyze the relationships between CAT, PA and PFit, and to explore the effects of different exercise modalities in a group of women with obesity. A total of 26 women (age: 23.41 ± 5.78 years-old) were enrolled in the cross-sectional study. PA, cardiorespiratory fitness, muscular strength, body composition and CAT were evaluated. The pilot intervention included 16 women randomized to a control (CON, n=5), high intensity interval training (HIIT, n = 5) and high-intensity circuit training (HICT, n=6) groups. Statistical analysis showed negative correlations between CAT and vigorous PA (VPA) (r s=-0.41, p=0.037); and between percent body fat (%BF), fat mass (FM), and all PA levels (r s=-0.41- -0.68, p<0.05); while muscle mass was positively associated with moderate-to-vigorous PA, and upper-body lean mass with all PA levels (r s =0.40-0.53, p<0.05). The HICT intervention showed significant improvements (p<0.05) in %BF, FM, fat free mass, and whole-body and lower extremities lean mass and strength after three weeks; however, only leg strength and upper extremities' FM improved significantly compared to CON and HICT. In conclusion, although all types of PA showed a positive influence on body fat content, only VPA significantly impacted on CAT volume. Moreover, three weeks of HICT induced positive changes in PFit in women with obesity. Further research is needed to explore VPA levels and high-intensity exercise interventions for short- and long-term CAT management.

Association between fat-free mass loss, changes in appetite and weight regain in individuals with obesity

BACKGROUND

The role of fat-free mass loss (FFML) in modulating weight regain, in individuals with obesity, as well as the potential mechanisms involved, remain inconsistent.

AIMS

To determine if % FFML following weight loss (WL) is a predictor of weight regain, and to investigate the association between %FFML and changes in appetite markers.

METHODS

Seventy individuals with obesity (BMI: 36±4kg/m²; age: 44±9 years; 29 males) underwent 8 weeks of a very low-energy diet (550-660 kcal/day), followed by 4 weeks of gradual refeeding and weight stabilization, and a 9-month maintenance program (eucaloric diet). Body weight and body composition (fat mass (FM) and FFM) (primary outcomes), as well as ß-hydroxybutyrate (ßHB) plasma concentration (a marker of ketosis) in fasting and appetite-related hormones (ghrelin, glucagon-like peptide 1, peptide YY, and cholecystokinin) and subjective appetite feelings, in fasting and every 30 minutes after a fixed breakfast for 2.5h (secondary outcomes), were measured at baseline, week 9 and 1 year (and week 13 in 35 subjects (25 males)). The association between FFML, weight regain and changes in appetite was assessed by linear regression.

RESULTS

WL at week 9 was 17.5±4.3kg and %FFML 20.4±10.6%. Weight regain at 1 year was 1.7±8.2kg (8.8±45.0%). After adjusting for WL and FM at baseline, %FFML at week 9 was not a significant predictor of weight regain. Similar results were seen at week 13. The greater the %FFML at week 9, but not 13, the smaller the reduction, or greater the increase in basal ghrelin concentration (ß:-3.2; 95% CI: -5.0, -1.1; P=0.003), even after adjusting for WL and ß-hydroxybutyrate.

CONCLUSION

%FFML was not a significant predictor of weight regain at 1-year in individuals with obesity. However, a greater %FFML was accompanied by a greater increase in ghrelin secretion under ketogenic conditions, suggesting a link between FFM and appetite regulation.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT01834859.

Physiological, perceptual and affective responses to high-intensity interval training using two work-matched programs with different bout duration in obese males

Objectives

This study compared physiological, perceptual, and affective responses to high-intensity interval training (HIIT) between two work-matched programs with different bout durations in obese males.

Methods

Sixteen low-to-moderately active obese men completed an eight-week cycling program of supervised HIIT (3 days/week) using either short bouts [48 × 10 s at 100% of peak power output (PPO) with 15 s of recovery (HIIT10)] or long bouts [8 × 60 s at 100% PPO with 90 s of recovery (HIIT60)]. Workload was progressively adjusted, to maintain high intensity (100% PPO), throughout training. Blood lactate (BLa), heart rate (HR), ratings of perceived exertion (RPE), and feeling scale ratings (pleasure/displeasure) were measured in each HIIT session.

Results

Average HR decreased in the last 2 weeks of training in both groups by 2.2 ± 1.8% of peak HR (p < 0.001). Training resulted in a reduction in BLa during exercise by 28 ± 19% (p < 0.001) from the 10th min onward only in HIIT10. Similarly, during the last weeks of training, RPE decreased (by 1.0 ± 1.1 units, p < 0.05) and feeling scale ratings were improved only in HIIT10, while RPE remained unchanged and feeling scale ratings deteriorated in HIIT60 (from 3.0 ± 1.1 to 2.1 ± 0.9 units, p < 0.001). No differences in post-exercise enjoyment were found.

Conclusion

Both HIIT formats induced similar HR adaptations, but improvement of BLa, perceptual and affective responses occurred only when bout duration was shorter. Our findings suggest that, in low-to-moderately active obese men, HIIT may be more effective in improving metabolic, perceptual, and affective responses when shorter, rather than longer, bouts of exercise are used.

The CLOCK 3111T/C polymorphism is associated with hour-by-hour physical activity levels only on weekends among Japanese male and female university students

BACKGROUND

CLOCK 3111T/C has been shown to be closely associated with morningness-eveningness, such as sleep-wake rhythms in healthy humans. However, previous studies examined the physical activity (PA) in a single day, and no study has investigated the relationships between CLOCK 3111T/C polymorphism and PA for an entire week. It was hypothesized that the CLOCK 3111T/C polymorphism might be associated with diurnal PA patterns, especially on the weekends.

METHODS

Eighty-one university students (male, n=14; female, n=67; age, 20.4±2.9 years) wore a digital accelerometer for 7 successive days, including the weekend, to collect hour-by-hour objectively-measured PA. CLOCK 3111T/C polymorphism was assessed using the oral mucosa. During the study, participants recorded their wake time and bedtime each day. Furthermore, lifestyle-related variables (i.e. morningness-eveningness, habitual meal and sleep timings) were collected using questionnaires. Linear mixed-effects models assessed the association of polymorphism (TT carriers vs. TC+CC carriers) with wake time and bedtime as well as daily PA throughout the week (time).

RESULTS

TT carriers had an earlier wake time (weekly mean: 44 min [95% CI, -82 to -5 min], time interaction: p=0.026) and bedtime (weekly mean: 30 min [95% CI, -61 min to - 15 sec], time interaction: p=0.048) than TC+CC carriers. Furthermore, TT carriers' wake time and bedtime on Saturday were significantly later than on other days (gene interaction: all p<0.05). On Saturday, the hour-by-hour PA in TT carriers was significantly greater than that in TC+CC carriers (hourly mean 1.7 min [95% CI, 0.2 to 3.4 min], time: p<0.001, group: p=0.028, interaction: p=0.155).

CONCLUSIONS

CLOCK 3111T/C polymorphism may be associated with objectively measured hour-by-hour PA only on Saturday. Academic/social obligations may mask the genetically determined biological rhythm of PA on weekdays.

Physical activity motives, barriers, and preferences in people with obesity: A systematic review

Background

Although the benefits of physical activity (PA) are well known, physical inactivity is highly prevalent among people with obesity. The objective of this systematic review was to i) appraise knowledge on PA motives, barriers, and preferences in individuals with obesity, and ii) quantify the most frequently reported PA motives, barriers and preferences in this population.

Methods

Six databases (Pubmed, CINAHL, Psyarticle, SportDiscus, Web of science and Proquest) were searched by independent reviewers to identify relevant quantitative or qualitative articles reporting PA motives, barriers or preferences in adults with body mass index ≥ 30 kg/m² (last searched in June 2020). Risk of bias for each study was assessed by two independent reviewers with the Mixed Methods Appraisal Tool (MMAT).

Results

From 5,899 papers identified, a total of 27 studies, 14 quantitative, 10 qualitative and 3 mixed studies were included. About 30% of studies have a MMAT score below 50% (k = 8). The three most reported PA motives in people with obesity were weight management, energy/physical fitness, and social support. The three most common PA barriers were lack of self-discipline/motivation, pain or physical discomfort, and lack of time. Based on the only 4 studies available, walking seems to be the preferred mode of PA in people with obesity.

Conclusions

Weight management, lack of motivation and pain are key PA motives and barriers in people with obesity, and should be addressed in future interventions to facilitate PA initiation and maintenance. Further research is needed to investigate the PA preferences of people with obesity.

Metabolic adaptation is associated with less weight and fat mass loss in response to low-energy diets

BACKGROUND

The practical relevance of metabolic adaptation remains a controversial issue. To the best of our knowledge, no study has properly evaluated the role of metabolic adaptation in modulating weight loss outcomes. Therefore, the aim of this study was to determine the association between metabolic adaptation, at the level of resting metabolic rate (RMR), and weight and fat mass (FM) loss after low-energy diets (LED), after adjusting for dietary adherence and other confounders.

METHODS

71 individuals with obesity (BMI: 34.6 ± 3.4 kg/m2; age: 45.4 ± 8.2 years; 33 males) were randomized to one of three 1000 kcal/day diets for 8 weeks. Body weight, FM and fat-free mass (FFM) (air displacement plethysmography), RMR (indirect calorimetry) and physical activity level (PAL) (armbands) were measured at baseline and at week 9. Metabolic adaptation at week 9 was defined as measured RMR minus predicted RMR at week 9. An equation to predict RMR was derived from baseline data of all participants that were part of this analysis and included age, sex, FM and FFM as predictors. Dietary adherence was calculated from RMR, PAL and body composition changes. Linear regression was used to assess the potential role of metabolic adaptation in predicting weight and FM loss after adjusting for dietary adherence, average PAL, sex, baseline FM and FFM and randomization group.

RESULTS

Participants lost on average 14 ± 4 kg of body weight (13 ± 3%) and presented with metabolic adaptation (-92 ± 110 kcal/day, P < 0.001). Metabolic adaptation was a significant predictor of both weight (β = -0.009, P < 0.001) and FM loss (β = -0.008, P < 0.001), even after adjusting for confounders (R2 = 0.88, 0.93, respectively, P < 0.001 for both). On average, an increase in metabolic adaptation of 50 kcal/day was associated with a 0.5 kg lower weight and FM loss in response to the LED.

CONCLUSION

In individuals with obesity, metabolic adaptation at the level of RMR is associated with less weight and FM loss in response to LED. Trial registration ID: NCT02944253.

Scoping Review of Healthcare Literature on Mobile, Wearable, and Textile Sensing Technology for Continuous Monitoring

Remote monitoring of health can reduce frequent hospitalisations, diminishing the burden on the healthcare system and cost to the community. Patient monitoring helps identify symptoms associated with diseases or disease-driven disorders, which makes it an essential element of medical diagnoses, clinical interventions, and rehabilitation treatments for severe medical conditions. This monitoring can be expensive and time-consuming and provide an incomplete picture of the state of the patient. In the last decade, there has been a significant increase in the adoption of mobile and wearable devices, along with the introduction of smart textile solutions that offer the possibility of continuous monitoring. These alternatives fuel a technology shift in healthcare, one that involves the continuous tracking and monitoring of individuals. This scoping review examines how mobile, wearable, and textile sensing technology have been permeating healthcare by offering alternate solutions to challenging issues, such as personalised prescriptions or home-based secondary prevention. To do so, we have selected 222 healthcare literature articles published from 2007 to 2019 and reviewed them following the PRISMA process under the schema of a scoping review framework. Overall, our findings show a recent increase in research on mobile sensing technology to address patient monitoring, reflected by 128 articles published in journals and 19 articles in conference proceedings between 2014 and 2019, which represents 57.65% and 8.55% respectively of all included articles.

Associations of movement behaviors and body mass index: comparison between a report-based and monitor-based method using Compositional Data Analysis

BACKGROUND/OBJECTIVES

Evidence on the associations between lifestyle movement behaviors and obesity has been established without taking into account the time-constrained nature of categorized, time-based lifestyle behaviors. We examined the associations of sleep, sedentary behavior (SED), light-intensity physical activity (LPA), and moderate-to-vigorous PA (MVPA) with body mass index (BMI) using Compositional Data Analysis (CoDA), and compared the associations between a report-based method (24-h Physical Activity Recall; 24PAR) and a monitor-based method (SenseWear Armband; SWA).

SUBJECTS/METHODS

Replicate data from a representative sample of 1247 adults from the Physical Activity Measurement Survey (PAMS) were used in the study. Participants completed activity monitoring on two randomly selected days, each of which required wearing a SWA for a full day, and then completing a telephone-administered 24PAR the following day. Relationships among behavioral compositional parts and BMI were analyzed using CoDA via multiple linear regression models with both 24PAR and SWA data.

RESULTS

Using 24PAR, time spent in sleep (γ = -3.58, p = 0.011), SED (γ = 3.70, p = 0.002), and MVPA (γ = -0.53, p = 0.018) was associated with BMI. Using SWA, time spent in sleep (γ = -5.10, p < 0.001), SED (γ = 8.93, p < 0.001), LPA (γ = -3.12, p < 0.001), and MVPA (γ = -1.43, p < 0.001) was associated with BMI. The SWA models explained more variance in BMI (R2 = 0.28) compared with the 24PAR models (R2 = 0.07). The compositional isotemporal substitution models revealed reductions in BMI when replacing SED by MVPA, LPA (not with 24PAR) or sleep for both 24PAR and SWA, but the effect estimates were larger with SWA.

CONCLUSIONS

Favorable levels of relative time spent in lifestyle movement behaviors were, in general, associated with decreased BMI. The observed associations were stronger using the monitor-based SWA method compared with the report-based 24PAR method.

Metabolic adaptation is an illusion, only present when participants are in negative energy balance

BACKGROUND

The existence of metabolic adaptation, following weight loss, remains a controversial issue. To our knowledge, no study has evaluated the role of energy balance (EB) in modulating metabolic adaptation.

OBJECTIVES

The aim of this study was to determine if metabolic adaptation, at the level of resting metabolic rate (RMR), is modulated by participants' EB status. A secondary aim was to investigate if metabolic adaptation was associated with weight regain.

METHODS

Seventy-one individuals with obesity (BMI: 34.6 ± 3.4 kg/m2; age: 45.4 ± 8.2 y; 33 men) enrolled in a 1000-kcal/d diet for 8 wk, followed by 4 wk of weight stabilization and a 9-mo weight loss maintenance program. Body weight/composition and RMR were measured at baseline, week 9 (W9), week 13 (W13), and 1 y (1Y). Metabolic adaptation was defined as a significantly different (lower or higher) measured compared with predicted RMR.

RESULTS

Participants lost on average 14 kg by W9, followed by weight stabilization at W13, and regained 29% of their initial weight loss at 1Y. Metabolic adaptation was found at W9 (-92 ± 110 kcal/d, P < 0.001) and W13 (-38 ± 124 kcal/d, P = 0.011) but was not correlated with weight regain. A significant reduction in metabolic adaptation was seen between W9 and W13 (-53 ± 101 kcal/d, P < 0.001). In a subset of participants who gained weight between W9 and W13 (n = 33), no metabolic adaptation was seen at W13 (-26.8 ± 121.5 kcal/d, P = 0.214). In a subset of participants with data at all time points (n = 45), metabolic adaptation was present at W9 and W13 (-107 ± 102 kcal/d, P < 0.001 and -49 ± 128 kcal/d, P = 0.013) but not at 1Y (-7 ± 129, P = 0.701).

CONCLUSION

After weight loss, metabolic adaptation at the level of RMR is dependent on the EB status of the participants, being reduced to half after a period of weight stabilization. Moreover, metabolic adaptation does not predict weight regain at 1Y follow-up. These trials were registered at clinicaltrials.gov as NCT02944253 and NCT03287726.

Declared and real physical activity in obese individuals as assessed by the questionnaire and accelerometer

BACKGROUND

Due to the lack of precise research data related to the evaluation of the physical activity level (PAL) among obese individuals, the aims of the study were to evaluate declared and real volume of physical activity, and to assess the correlations between these methods.

METHODS

The study consisted of 30 female (M<inf>age</inf>=32.9±7.3 years) and 16 male (M<inf>age</inf>=36.4±8.4 years) a total of 46 obese volunteer individuals were included (M<inf>bmi</inf>: 37.6±6.6 kg/m², M<inf>bmi</inf>: 34.2±4.3 kg/m²; body fat percentage: 42.1% and 35.2%, respectively). A cross-sectional study was conducted on the obese people. The information form was prepared for obese individuals who applied the Health Institutions and body composition measurements were performed with Tanita BC-1000. PAL was assessed objectively by a Sense Wear Armband (SWA) for 7 consecutive days- and seven day later the participants fill out the International Physical Activity Questionnaire - Short Form (IPAQ-SF). For statistical analysis, the data were presented as mean values, Standard deviations (SD), frequency (f), and percentage (%). Spearman's Rho Correlation were used, and the significant level was P<0.05.

RESULTS

According to IPAQ and SWA, 69.6% (10.9% plus 58.7%) of the participants (N.=32) estimated activity levels as "correct." The PAL of 30.4% (N.=14) of the participants does not seem to be consistent. According to the IPAQ and SWA, the rates of moderate-vigorous physical activity (MVPA) were 80.4%, 67.4% respectively. Weak correlation was found-between IPAQ-MET and SWA-step/day and SWA-MET respectively (r<inf>(</inf>s)=0.381; 0.410 (P<0.01).

CONCLUSIONS

Physical activity level being assessed by a subjective method was different from the objective method in obese individuals. In addition to this, sample groups and limitations should be taken into consideration when determining suitable methods.

Physiological Predictors of Weight Regain at 1-Year Follow-Up in Weight-Reduced Adults with Obesity

OBJECTIVE

This study aimed to assess whether changes in resting metabolic rate (RMR), exercise-induced energy expenditure (EIEE), and appetite following weight loss (WL) are associated with weight regain at 1 year.

METHODS

Thirty-six adults with obesity underwent 8 weeks of a very-low-energy diet, followed by 4 weeks of refeeding and a 1-year maintenance program. RMR, EIEE, appetite ratings, and active ghrelin, peptide YY, glucagon-like peptide-1, cholecystokinin, and insulin concentrations were measured at baseline, week 13, and 1 year.

RESULTS

A 17% WL (-20 ± 5 kg [mean ± SD]; range: -11.7 to -32.2 kg; P < 0.001) was achieved at week 13. After 1 year, weight regain was 2.5 ± 9.0 kg (not significant), ranging from -18.2 to 22.5 kg. Both fat mass and fat-free mass were reduced at week 13 (-17.9 ± 4.8 and -2.9 ± 2.7 kg, respectively; P < 0.001), while only loss of fat mass was sustained at 1 year. WL was associated with reduced RMR, EIEE, and fasting/postprandial insulin (all P < 0.001), as well as increased fasting hunger (P < 0.01) and fasting/postprandial active ghrelin (P < 0.001). There were no significant correlations between changes in RMR, EIEE, or appetite with WL and weight regain at 1 year.

CONCLUSIONS

No clear evidence emerged that changes in RMR, EIEE, or appetite following WL can predict weight regain at 1 year, but larger studies are needed to confirm these results.

Investigating the effect of sex and ketosis on weight-loss-induced changes in appetite

BACKGROUND

Diet-induced weight loss (WL) is usually accompanied by increased appetite, a response that seems to be absent when ketogenic diets are used. It remains unknown if sex modulates the appetite suppressant effect of ketosis.

OBJECTIVE

The aim of this study was to examine if sex modulates the impact of WL-induced changes in appetite and if ketosis alters these responses.

METHODS

Ninety-five individuals (55 females) with obesity (BMI [kg/m 2]: 37  ± 4) underwent 8 wk of a very-low-energy diet, followed by 4 wk of refeeding and weight stabilization. Body composition, plasma concentration of β-hydroxybutyrate (β-HB) and appetite-related hormones (active ghrelin, active glucagon-like peptide 1 [GLP-1], total peptide YY [PYY], cholecystokinin and insulin), and subjective feelings of appetite were measured at baseline, week 9 in ketosis, and week 13 out of ketosis.

RESULTS

The mean WL at week 9 was 17% for males and 15% for females, which was maintained at week 13. Weight, fat, and fat-free mass loss were greater in males (P < 0.001 for all) and the increase in β-HB at week 9 higher in females (1.174 ± 0.096 compared with 0.783 ± 0.112 mmol/L, P = 0.029). Basal and postprandial GLP-1 and postprandial PYY (all P < 0.05) were significantly different for males and females. There were no significant sex × time interactions for any other appetite-related hormones or subjective feelings of appetite. At week 9, basal GLP-1 was decreased only in males (P < 0.001), whereas postprandial GLP-1 was increased only in females (P < 0.001). No significant changes in postprandial PYY were observed over time for either sex.

CONCLUSIONS

Ketosis appears to have a greater beneficial impact on GLP-1 in females. However, sex does not seem to modulate the changes in the secretion of other appetite-related hormones, or subjective feelings of appetite, seen with WL, regardless of the ketotic state. This trial was registered at clinicaltrials.gov as NCT01834859.

Effectiveness of interventions aiming at reducing sedentary behaviour in a non-surgical population with overweight or obesity: A systematic review and meta-analysis

AIM

This systematic review and meta-analyses of randomised controlled trials (RCTs) investigated the effectiveness of interventions to reduce sedentary behaviour amongst people with overweight or obesity. Secondarily, it aimed to investigate the effectiveness of these interventions on body mass index (BMI), time spent in moderate-to-vigorous physical activity (MVPA) and health-related quality of life (HRQoL).

METHODS

A search of six databases (CENTRAL, PubMed, Embase, PEDro, CINAHL and PsycINFO) was conducted from inception to July 2018. RCTs in which sedentary behaviour was measured by accelerometry or inclinometry, with participants of any age with overweight or obesity were included. Subgroup analyses were undertaken comparing studies that included adults versus children and studies with an active component (e.g., treadmill desk, physically active breaks) versus no active component to their intervention.

RESULTS

Nine studies (n=1859) were included. Compared to the control group, the interventions significantly reduced time spent in sedentary behaviour (standardised mean difference [95% confidence interval] -0.33 [-0.59 to -0.08] overall; -0.53 [-0.95 to -0.11] in adults). Subgroup analyses demonstrated that only interventions that included active components reduced time spent in sedentary behaviour (-0.54 [-0.88 to -0.20]) and increased time spent in MVPA (1.29 [0.02 to 2.56]). Subgroup analyses demonstrated that interventions only reduced BMI in studies of children (-0.09 [-0.18 to -0.00]) and in those with no active component (-0.09 [-0.18 to -0.01]). There were insufficient data to investigate the effectiveness of these interventions on HRQoL.

CONCLUSIONS

This novel systematic review and meta-analyses suggests interventions aiming to effectively reduce objectively-measured sedentary behaviour need to specifically include an active component.

The Role of Objectively Measured, Altered Physical Activity Patterns for Body Mass Index Change during Inpatient Treatment in Female Patients with Anorexia Nervosa

Increased physical activity (PA) affects outcomes in patients with anorexia nervosa (AN). To objectively assess PA patterns of hospitalized AN patients in comparison with healthy, outpatient controls (HC), and to analyze the effect of PA on Body Mass Index (BMI) change in patients with AN, we measured PA in 50 female patients with AN (median age = 25 years, range = 18–52 years; mean BMI = 14.4 ± 2.0 kg/m²) at the initiation of inpatient treatment and in 30 female healthy controls (median age = 26 years, range = 19–53 years; mean BMI = 21.3 ± 1.7 kg/m²) using the SenseWear™ armband. Duration of inpatient stay and weight at discharge were abstracted from medical records. Compared with controls, AN patients spent more time in very light-intensity physical activity (VLPA) (median VLPA = 647 vs. 566 min/day, p = 0.004) and light-intensity physical activity (LPA) (median LPA = 126 vs. 84 min/day, p < 0.001) and less time in moderate-intensity physical activity (MPA) (median MPA = 82 vs. 114 min/day, p = 0.022) and vigorous physical activity (VPA) (median VPA = 0 vs. 16 min/day, p < 0.001). PA and BMI increase were not associated in a linear model, and BMI increase was mostly explained by lower admission BMI and longer inpatient stay. In a non-linear model, an influence of PA on BMI increase seemed probable (jack knife validation, r² = 0.203; p < 0.001). No direct association was observed between physical inactivity and BMI increase in AN. An altered PA pattern exists in AN patients compared to controls, yet the origin and consequences thereof deserve further investigation.

Investigation of the long-term sustainability of changes in appetite after weight loss

Background/Objective

Diet-induced weight loss (WL) leads to a compensatory increase in appetite and changes in the plasma concentration of appetite-regulating hormones are likely to play a role. Whether these changes are transient or sustained remains unclear. This study aimed to assess if changes in subjective and objective appetite markers observed with WL are sustained after 1 year (1Y).

Subjects/Methods

In total 100 (45 males) individuals with obesity (BMI: 37 ± 4 kg/m², age: 43 ± 10 years) underwent 8 weeks (wks) of a very-low energy diet (VLED), followed by 4 wks refeeding, and a 1Y maintenance program. Fasting/postprandial subjective ratings of hunger, fullness, desire to eat, and prospective food consumption (PFC) were assessed, and plasma concentration of active ghrelin (AG), total peptide YY (PYY), active glucagon-like peptide 1, cholecystokinin (CCK), and insulin measured, at baseline, week 13 (Wk13) and 1Y.

Results

At Wk13, 16% WL (−18 ± 1 kg, P < 0.001) was associated with a significant increase in fasting and postprandial hunger ratings (P < 0.01 and P < 0.05, respectively), and postprandial fullness (P < 0.01) combined with a reduction in PFC (P < 0.001). These were accompanied by a significant rise in basal and postprandial AG concentrations (P < 0.001, for both), a reduction in postprandial CCK (P < 0.01) and in basal and postprandial insulin (P < 0.001). At 1Y follow-up, with sustained WL (15%; −16 ± 1 kg, P < 0.001), fasting hunger and postprandial fullness ratings remained increased (P < 0.05 for both), and postprandial PFC reduced (P < 0.001). Basal and postprandial AG remained elevated and insulin reduced (P < 0.001, for all), while postprandial CCK was increased (P < 0.01) and PYY decreased (P < 0.001).

Conclusion

With a 15% sustained WL at 1Y, the drive to eat in the fasting state is increased, but this may be balanced out by raised postprandial feelings of fullness. To assist with WL maintenance, new strategies are required to manage increased hunger and drive to eat.

Timeline of changes in adaptive physiological responses, at the level of energy expenditure, with progressive weight loss

Diet-induced weight loss (WL) is associated with reduced resting and non-resting energy expenditure (EE), driven not only by changes in body composition but also potentially by adaptive thermogenesis (AT). When exactly this happens, during progressive WL, remains unknown. The aim of this study was to determine the timeline of changes in RMR and exercise-induced EE (EIEE), stemming from changes in body composition v. the presence of AT, during WL with a very-low-energy diet (VLED). In all, thirty-one adults (eighteen men) with obesity (BMI: 37 (sem 4·5) kg/m²; age: 43 (sem 10) years) underwent 8 weeks of a VLED, followed by 4 weeks of weight maintenance. Body weight and composition, RMR, net EIEE (10, 25 and 50 W) and AT (for RMR (AT_RMR) and EIEE (AT_EIEE)) were measured at baseline, day 3 (2 (sem 1) % WL), after 5 and 10 % WL and at weeks 9 (16 (sem 2) %) and 13 (16 (sem 1) %). RMR and fat mass were significantly reduced for the first time at 5 % WL (12 (sem 8) d) (P<0·01 and P<0·001, respectively) and EIEE at 10 % WL (32 (sem 8) d), for all levels of power (P<0·05), and sustained up to week 13. AT_RMR was transiently present at 10 % WL (−460 (sem 690) kJ/d, P<0·01). A fall in RMR should be anticipated at ≥5 % WL and a reduction in EIEE at ≥10 % WL. Transient AT_RMR can be expected at 10 % WL. These physiological adaptations may make progressive WL difficult and will probably contribute to relapse.

Effects of Body Mass Index on Bone Loading Due to Physical Activity

The aim of the current study was to compare bone loading due to physical activity between lean, and overweight and obese individuals. Fifteen participants (lower BMI group: BMI < 25 kg/m², n = 7; higher BMI group: 25 kg/m² < BMI < 36.35 kg/m², n = 8) wore a tri-axial accelerometer on 1 day to collect data for the calculation of bone loading. The International Physical Activity Questionnaire (short form) was used to measure time spent at different physical activity levels. Daily step counts were measured using a pedometer. Differences between groups were compared using independent t-tests. Accelerometer data revealed greater loading dose at the hip in lower BMI participants at a frequency band of 0.1-2 Hz (P = .039, Cohen's d = 1.27) and 2-4 Hz (P = .044, d = 1.24). Lower BMI participants also had a significantly greater step count (P = .023, d = 1.55). This corroborated with loading intensity (d ≥ 0.93) and questionnaire (d = 0.79) effect sizes to indicate higher BMI participants tended to spend more time in very light activity, and less time in light and moderate activity. Overall, participants with a lower BMI exhibited greater bone loading due to physical activity; participants with a higher BMI may benefit from more light and moderate level activity to maintain bone health.

Obesity History and Daily Patterns of Physical Activity at Age 60-64 Years: Findings From the MRC National Survey of Health and Development

Background

The aim of this study was to investigate associations of current body mass index (BMI) and obesity history with daily patterns of physical activity.

Methods

At age 60-64, participants from a British birth cohort study wore accelerometers for 5 days. Accelerometry counts were log-transformed and mean log-counts were used to derive a summary variable indicating total daily log-activity counts. Among those with complete data (n = 1,388) the associations of current BMI and age of first obesity were examined with: (a) total daily log-activity counts and (b) total log-activity counts in four segments of the day.

Results

Higher current BMI and younger age at obesity were strongly associated with lower levels of total daily activity at age 60-64 even after adjustment for sex, socioeconomic factors, and health status. The fully-adjusted mean difference in total daily log-activity counts was -581.7 (95% confidence interval: -757.2, -406.3) when comparing BMI ≥35 kg/m2 with <25 kg/m2, representing an 18.4% difference. Participants who had been obese since early adulthood had the lowest levels of activity (mean difference in total daily log-activity counts was -413.1 (-638.1, -188.2) when comparing those who were obese by age 26 or 36 with those who were never obese, representing a 13.1% difference).

Conclusions

Obese older adults may require targeted interventions and additional support to improve their daily activity levels. As younger generations with greater lifetime exposure to obesity reach old age the proportion of adults achieving sufficient levels of activity to realize its associated health benefits is likely to decline.

Timeline of changes in appetite during weight loss with a ketogenic diet

Background/objective:

Diet-induced weight loss (WL) leads to increased hunger and reduced fullness feelings, increased ghrelin and reduced satiety peptides concentration (glucagon-like peptide-1 (GLP-1), cholecystokinin (CCK) and peptide YY (PYY)). Ketogenic diets seem to minimise or supress some of these responses. The aim of this study was to determine the timeline over which changes in appetite occur during progressive WL with a ketogenic very-low-energy diet (VLED).

Subjects/methods:

Thirty-one sedentary adults (18 men), with obesity (body mass index: 37±4.5 kg m⁻²) underwent 8 weeks (wks) of a VLED followed by 4 wks of weight maintenance. Body weight and composition, subjective feelings of appetite and appetite-related hormones (insulin, active ghrelin (AG), active GLP-1, total PYY and CCK) were measured in fasting and postprandially, at baseline, on day 3 of the diet, 5 and 10% WL, and at wks 9 and 13. Data are shown as mean±s.d.

Results:

A significant increase in fasting hunger was observed by day 3 (2±1% WL), (P<0.01), 5% WL (12±8 days) (P<0.05) and wk 13 (17±2% WL) (P<0.05). Increased desire to eat was observed by day 3 (P<0.01) and 5% WL (P<0.05). Postprandial prospective food consumption was significantly reduced at wk 9 (16±2% WL) (P<0.01). Basal total PYY was significantly reduced at 10% WL (32±8 days) (P<0.05). Postprandial active GLP-1 was increased at 5% WL (P<0.01) and CCK reduced at 5 and 10% WL (P<0.01, for both) and wk 9 (P<0.001). Basal and postprandial AG were significantly increased at wk 13 (P<0.001, both).

Conclusions:

WL with a ketogenic VLED transiently increases the drive to eat up to 3 weeks (5% WL). After that, and while participants are ketotic, a 10–17% WL is not associated with increased appetite. However, hunger feelings and AG concentrations increase significantly from baseline, once refeeding occurs.

The impact of rate of weight loss on body composition and compensatory mechanisms during weight reduction: A randomized control trial

BACKGROUND & AIMS

Rapid weight loss (WL) has been associated with a larger loss of fat free mass and a disproportional reduction in resting metabolic rate (RMR), but the evidence is inconclusive. We aimed to evaluate the impact of WL rate on body composition and compensatory mechanisms activated with WL (reduced RMR, increased exercise efficiency (ExEff) and appetite), both during negative and neutral energy balance (EB).

METHODS

Thirty-five participants with obesity were randomized to lose a similar weight rapidly (4 weeks) or gradually (8 weeks), and afterwards to maintain it (4 weeks). Body weight and composition, RMR, ExEff (10, 25 and 50 W), appetite feelings and appetite-regulating hormones (active ghrelin, cholecystokinin, total peptide YY (PYY), active glucagon-like peptide-1 and insulin), in fasting and every 30 min up to 2.5 h, were measured at baseline and after each phase.

RESULTS

Changes in body weight (≈9%) and composition were similar in both groups. With WL, RMR decreased and ExEff at 10 W increased significantly in the rapid WL group only. However, fasting hunger increased significantly with gradual WL only, while fasting and postprandial prospective food consumption, and postprandial hunger decreased (and postprandial fullness increased) significantly with rapid WL only. Basal total PYY, and basal and postprandial insulin decreased significantly, and similarly in both groups. After weight stabilization and no ketosis no differences between groups were found.

CONCLUSIONS

Despite differences while under negative EB, WL rate does not seem to have a significant impact on body composition or on compensatory mechanisms, once EB is reestablished.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01912742 (the study was registered in clinicaltrial.gov).

Minimum number of days required for a reliable estimate of daily step count and energy expenditure, in people with MS who walk unaided

BACKGROUND AND PURPOSE

The purpose of this study was to examine the minimum number of days needed to reliably estimate daily step count and energy expenditure (EE), in people with multiple sclerosis (MS) who walked unaided.

METHODS

Seven days of activity monitor data were collected for 26 participants with MS (age=44.5±11.9years; time since diagnosis=6.5±6.2years; Patient Determined Disease Steps=≤3). Mean daily step count and mean daily EE (kcal) were calculated for all combinations of days (127 combinations), and compared to the respective 7-day mean daily step count or mean daily EE using intra-class correlations (ICC), the Generalizability Theory and Bland-Altman.

RESULTS

For step count, ICC values of 0.94-0.98 and a G-coefficient of 0.81 indicate a minimum of any random 2-day combination is required to reliably calculate mean daily step count. For EE, ICC values of 0.96-0.99 and a G-coefficient of 0.83 indicate a minimum of any random 4-day combination is required to reliably calculate mean daily EE. For Bland-Altman analyses all combinations of days, bar single day combinations, resulted in a mean bias within ±10%, when expressed as a percentage of the 7-day mean daily step count or mean daily EE.

CONCLUSIONS

A minimum of 2days for step count and 4days for EE, regardless of day type, is needed to reliably estimate daily step count and daily EE, in people with MS who walk unaided.

Short- and long-term effectiveness of a three-month individualized need-supportive physical activity counseling intervention at the workplace

Background

The objective of the present study was to evaluate the short- and long-term intervention and mediation effects of a 3-month individualized need-supportive physical activity (PA) counseling intervention on employees’ PA and sedentary behavior.

Methods

Insufficiently active employees (n = 300; mean age 42 ± 9 years; 78% female) were recruited from a large pharmaceutical company in Flanders, Belgium. A quasi-experimental design was used in which the intervention group (N = 246) was recruited separately from the reference group (N = 54). Intervention group participants received a 3-month behavioral support intervention, which consisted of two one-hour face-to-face counseling sessions and three follow-up counseling contacts by e-mail or telephone at weeks three, six and nine. PA counseling, delivered by qualified PA counselors, aimed to satisfy participants’ basic psychological needs for autonomy, competence, and relatedness. Reference group participants did not receive individualized PA counseling. Outcome measures included objectively assessed and self-reported PA and sedentary time and psychological need satisfaction. Assessments were held at baseline, immediately after the intervention (short-term) and 6 months post-intervention (long-term). Mixed model analyses and bootstrapping analyses were used to determine intervention and mediation effects, respectively.

Results

The intervention group increased weekday daily steps both in the short- and long-term, while the reference group showed reductions in daily step count (ES = .65 and ES = .48 in the short- and long-term, respectively). In the short-term, weekday moderate-to-vigorous PA increased more pronouncedly in the intervention group compared to the reference group (ES = .34). Moreover, the intervention group demonstrated reductions in self-reported sitting time during weekends both in the short- and long-term, whereas the reference group reported increased sitting time (ES = .44 and ES = .32 in the short- and long-term, respectively). Changes in perceived autonomy and competence need satisfaction mediated the long-term intervention effects on daily step count.

Conclusions

A 3-month individualized need-supportive PA counseling intervention among employees resulted in significant and sustained improvements in weekday daily step count and in decreased self-reported sitting during weekends. Our findings contribute to the growing evidence of the long-term effectiveness of need-supportive PA counseling.

Trial registration

ClinicalTrials.gov NCT01759927. Registered December 30, 2012.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3965-1) contains supplementary material, which is available to authorized users.

The Norwegian Healthy Life Study: protocol for a pragmatic RCT with longitudinal follow-up on physical activity and diet for adults

BACKGROUND

The Norwegian Directorate of Health recommends that Healthy Life Centres (HLCs) be established in primary health care to support behaviour change and reduce the risk of non-communicable diseases. The aim of the present study protocol is to present the rationale, design and methods of a combined pragmatic randomized controlled trial (RCT) and longitudinal cohort study of the effects of attending HLCs concerning physical activity, sedentary behaviour and diet and to explore how psychological well-being and motivational factors may mediate short- and long-term effects.

METHODS

The present study will combine a 6-month RCT with a longitudinal cohort study (24 months from baseline) conducted at six HLCs from June 2014 to Sept 2017. Participants are randomized to behavioural change interventions or a 6-month waiting list control group.

DISCUSSION

A randomized trial of interventions in HLCs has the potential to influence the development of policy and practice for behaviour change interventions and patient education programmes in Norway. We discuss some of the important preconditions for obtaining valid results from a complex intervention and outline some of the characteristics of ecological approaches in health care research that can enable a pragmatic intervention study.

TRIAL REGISTRATION

The study was retrospectively registered on September 19, 2014 and is available online at ClinicalTrials.gov (ID: NCT02247219 ).

Quantifying the effect of body mass index, age, and depression severity on 24-h activity patterns in persons with a lifetime history of affective disorders

BACKGROUND

Patients with affective disorders of different ages have been found to present weight changes and different circadian activity patterns. This study assessed the effects of age, Body Mass Index (BMI) and depression severity on the activity-rest cycle in persons with affective disorders using a novel multifactorial 24-h analysis method.

METHODS

Two hundred and thirty-six participants aged between 14 and 85 years underwent 5 to 22 days of actigraphy monitoring (mean duration = 14 days). BMI was also recorded and symptom severity was assessed with the Hamilton Depression Rating Scale (HDRS). Participants were divided into two groups: healthy controls (n = 68) and participants with a lifetime diagnosis of affective disorders (n = 168). First, the multiple regression method was employed to formulate the circadian activity pattern in term of the factors age, BMI and HDRS. For each group, the functional linear analysis method was applied to assess the relative effects of the factors. Finally, Wald-tests were used to assess the contribution of each factor on the circadian activity pattern.

RESULTS

In the affective disorders group, higher BMI was associated with higher activity levels from 3 am until 5.30 am and with lower activity levels from 10 am until 10.30 pm. Older age was associated with less activity across the day, evening, and night - from 11 am until 5.30 am. Higher HDRS scores were associated with higher activity around 1:30 am. In healthy controls, the effects of BMI and age on activity patterns were less pronounced and affected a narrower portion of the 24-h period.

CONCLUSION

These findings suggest that older age and higher BMI are linked to lower daytime activity levels. Higher BMI and worse symptom severity were also associated with nocturnal activity patterns suggestive of sleep disturbances. The influence of age and BMI on 24-h activity profiles appear to be especially pronounced in people with affective disorders.

The Association of Physical Activity during Weekdays and Weekend with Body Composition in Young Adults

Physical activity (PA) is a key contributor in long-term weight management but there remains limited research on the association between weekly PA patterns and weight change. The purpose of the present study was to examine the prospective association between weekly PA patterns and weight change in generally healthy young adults. Anthropometric measurements, including dual X-ray absorptiometry, were obtained every 3 months over a period of one year in 338 adults (53% male). At each measurement time, participants wore a multisensor device for a minimum of 10 days to determine total daily energy expenditure and time spent sleeping, sedentary, in light PA (LPA), in moderate PA (MPA), and in vigorous PA (VPA). PA did not differ between weekdays and the weekend at baseline. Twenty-four-hour sleep time, however, was significantly longer during weekends compared to weekdays, which was associated with less time spent sedentary. Weight loss was associated with a significant increase in LPA at the expense of sedentary time during the weekend but not during weekdays. Regression analyses further revealed an inverse association between change in VPA during the weekend and body composition at 12-month follow-up. Taken together, these results suggest that weekend PA plays an important role in long-term weight management.

Leisure time computer use and overweight development in young adults--a prospective study

Background

The prevalence of overweight among Swedish young adults has nearly doubled since the 1980s. The weight increase has been paralleled by the increased use of computers at work, at school, and at leisure time. The aim was to examine leisure time computer use for gaming, and for emailing/chatting, in relation to overweight development in young adults.

Methods

A prospective cohort study with Swedish young adults (20–24 years at baseline) who responded to a questionnaire at baseline (n = 6735), and after 1 year (n = 3928) and 5 years (n = 2593). Exposure variables were average daily time spent on leisure time computer gaming and emailing/chatting. Logistic regression was performed for cross-sectional analyses with overweight (BMI ≥ 25) and obesity (BMI ≥ 30) as the outcomes, and for prospective analyses with new cases of overweight at the 1- and 5-year follow-ups. Change in BMI from baseline to 5 year-follow-up was analyzed with linear regression.

Results

There were cross-sectional and prospective associations between computer gaming and overweight (BMI ≥ 25) in women, after adjusting for age, occupation, physical activity, sleep, social support, and total computer use. For the men, only cross-sectional associations could be seen. Spending more than 2 h daily for emailing and chatting was related cross-sectionally to overweight in the women. No clear prospective associations were found for emailing/chatting and overweight development in either sex.

Conclusions

We have identified a new risk group for overweight development: young adult female computer gamers. Leisure time computer gaming was a prospective risk factor for overweight in women even after adjusting for demographic and lifestyle factors, but not in men. There were no clear prospective associations between computer use for emailing/chatting and overweight in either sex.

Temporal patterns of physical activity and sedentary behavior in 10-14 year-old children on weekdays

Background

An important but often ignored aspect of physical activity (PA) and sedentary behavior (SB) is the chronological succession of activities, or temporal pattern. The main purposes of this study were (1) to investigate when certain types of PA and SB compete against each other during the course of the day and (2) compare intensity- and domain-specific activity levels during different day-segments.

Methods

The study sample consists of 211 children aged 10–14, recruited from 15 primary and 15 secondary schools. PA was assessed combining the SenseWear Mini Armband (SWM) with an electronic activity diary. The intensity- and domain-specific temporal patterns were plotted and PA differences between different day-segments (i.e., morning, school, early evening and late evening) were examined using repeated-measures ANCOVA models.

Results

Physical activity level (PAL) was highest during the early evening (2.51 MET_SWM) and school hours (2.49 MET_SWM); the late evening segment was significantly less active (2.21 MET_SWM) and showed the highest proportion of sedentary time (54 % of total time-use). Throughout the different day-segments, several domains of PA and SB competed with each other. During the critical early-evening segment, screentime (12 % of time-use) and homework (10 %) were dominant compared to activity domains of sports (4 %) and active leisure (3 %). The domain of active travel competed directly with motor travel during the morning (5 % and 6 % respectively) and early-evening segment (both 8 %).

Conclusions

Throughout the day, different aspects of PA and SB go in competition with each other, especially during the time period immediately after school. Detailed information on the temporal patterns of PA and SB of children could help health professionals to develop more effective PA interventions and promotion strategies. By making adaptations to the typical day schedule of children (e.g., through the introduction of extra-curricular PA after school hours), their daily activity levels might improve.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2093-7) contains supplementary material, which is available to authorized users.

Do overweight workers profit by workplace health promotion, more than their normal-weight peers? Evaluation of a worksite intervention

Background

Worksite health promotion programs have been identified as strongly effective in decreasing body weight and increasing awareness and change in health behavior. Aim of this study is to determine the effects of a multi-component intervention in workplace health promotion.

Methods

In a controlled study trail, 1,573 workers of a logistics company had the chance to participate in a one year worksite health promotion program. Main elements of the multi-component intervention were physical activity training in combination with nutrition counseling. Employees completed a questionnaire at baseline and then again after twelve month. Main outcome variables were changes in body weight and health behaviors. Secondary outcomes were subjective health indicators.

Results

Our results showed preliminary improvements in physical activity and eating behavior among normal weight and overweight/obesity weight groups. No significant weight reduction could be found, only a minimal reduction of BMI. The reduction was larger in the overweight group. Workers considered overweight or obese showed significantly greater body weight loss and changes in eating behavior than workers with a normal weight status. Workers with obesity/overweight scored their general health status significantly lower than their colleagues with normal weight status. No significant improvements were found for overall perception of health status between baseline and follow-up in the BMI-groups.

Conclusion

This 12-month intervention-control study suggests that a well-implemented multi-component workplace health promotion program may support substantial change in health behavior (e.g. nutrition and physical activity). It is indicated that overweight employees may especially profit from such worksite health promotion. An investigation of long-term effects of this multi-component intervention is strongly recommended.

Self-Directed Weight Loss Strategies: Energy Expenditure Due to Physical Activity Is Not Increased to Achieve Intended Weight Loss

Reduced physical activity and almost unlimited availability of food are major contributors to the development of obesity. With the decline of strenuous work, energy expenditure due to spontaneous physical activity has attracted increasing attention. Our aim was to assess changes in energy expenditure, physical activity patterns and nutritional habits in obese subjects aiming at self-directed weight loss.

METHODS

Energy expenditure and physical activity patterns were measured with a portable armband device. Nutritional habits were assessed with a food frequency questionnaire.

RESULTS

Data on weight development, energy expenditure, physical activity patterns and nutritional habits were obtained for 105 patients over a six-month period from an initial cohort of 160 outpatients aiming at weight loss. Mean weight loss was -1.5 ± 7.0 kg (p = 0.028). Patients with weight maintenance (n = 75), with substantial weight loss (>5% body weight, n = 20) and with substantial weight gain (>5% body weight, n = 10) did not differ in regard to changes of body weight adjusted energy expenditure components (total energy expenditure: -0.2 kcal/kg/day; non-exercise activity thermogenesis: -0.3 kcal/kg/day; exercise-related activity thermogenesis (EAT): -0.2 kcal/kg/day) or patterns of physical activity (duration of EAT: -2 min/day; steps/day: -156; metabolic equivalent unchanged) measured objectively with a portable armband device. Self-reported consumption frequency of unfavorable food decreased significantly (p = 0.019) over the six-month period.

CONCLUSIONS

An increase in energy expenditure or changes of physical activity patterns (objectively assessed with a portable armband device) are not employed by obese subjects to achieve self-directed weight loss. However, modified nutritional habits could be detected with the use of a food frequency questionnaire.

Associations of physical activity with depressiveness and coping in subjects with high-grade obesity aiming at bariatric surgery: a cross-sectional study

Background

Reduced physical activity is supposed to be associated with depressiveness and more passive coping patterns. For further evaluation of this assumed relation we studied energy expenditure due to physical activity - usually referred to as activity thermogenesis (AT) - together with depressiveness (clinical diagnosis, depression module of the Patient Health Questionnaire), and coping behaviours (Brief COPE Inventory) in 50 patients with high-grade obesity (42 ± 12 years; 9 with II° and 41 with III° obesity) aiming at bariatric surgery.

Methods

AT was assessed with a portable armband device (SenseWear™ armband). Depressiveness and coping were assessed using validated questionnaires.

Results

Weight-adjusted non-exercise AT and intensity of physical activity (metabolic equivalent) correlated inversely with body mass index (non-exercise AT: r = −0.32, P < 0.05; mean metabolic equivalent: r = −0.37, P < 0.01) but not with depressiveness. The coping strategies “support coping” and “active coping” showed significant inverse correlations to a) weight-adjusted non-exercise AT (“support coping”: r = −0.34, P < 0.05; “active coping”: r = −0.36, P < 0.05), b) weight-adjusted exercise-related AT (“support coping”: r = −0.36, P < 0.05; “active coping”: r = −0.38, P < 0.01) and c) intensity of physical activity (for mean metabolic equivalent: “support coping”: r = −0.38, P < 0.01; “active coping”: r = −0.40, P < 0.01; for duration of exercise-related AT: “support coping”: r = −0.36, P < 0.05; “active coping”: r = −0.38, P < 0.01).

Conclusions

AT was not associated with depressiveness. Furthermore, supposed adaptive coping strategies of individuals aiming at bariatric surgery were negatively associated with AT.

The Impact of Different Degrees of Feedback on Physical Activity Levels: A 4-Week Intervention Study

Assessing levels of physical activity (PA) and providing feedback about these levels might have an effect on participant's PA behavior. This study discusses the effect of different levels of feedback--from minimal to use of a feedback display and coach--on PA over a 4-week intervention period. PA was measured at baseline, during and immediately after the intervention. Participants (n=227) were randomly assigned to a Minimal Intervention Group (MIG-no feedback), Pedometer Group (PG-feedback on steps taken), Display Group (DG-feedback on steps, minutes of moderate to vigorous physical activity and energy expenditure) or Coaching Group (CoachG-same as DG with need-supportive coaching). Two-way ANCOVA showed no significant Group×Time interaction effect for the different PA variables between the MIG and PG. Also no differences emerged between PG and DG. As hypothesized, CoachG had higher PA values throughout the intervention compared with DG. Self-monitoring using a pedometer resulted in more steps compared with a no-feedback condition at the start of the intervention. However, adding individualized coaching seems necessary to increase the PA level until the end of the intervention.

Descriptive study of sedentary behaviours in 35,444 French working adults: cross-sectional findings from the ACTI-Cités study

Background

Given the unfavourable health outcomes associated with sedentary behaviours, there is a need to better understand the context in which these behaviours take place to better address this public health concern. We explored self-reported sedentary behaviours by type of day (work/non-work), occupation, and perceptions towards physical activity, in a large sample of adults.

Methods

We assessed sedentary behaviours cross-sectionally in 35,444 working adults (mean ± SD age: 44.5 ± 13.0 y) from the French NutriNet-Santé web-based cohort. Participants self-reported sedentary behaviours, assessed as domain-specific sitting time (work, transport, leisure) and time spent in sedentary entertainment (TV/DVD, computer and other screen-based activities, non-screen-based activities) on workdays and non-workdays, along with occupation type (ranging from mainly sitting to heavy manual work) and perceptions towards physical activity. Associations of each type of sedentary behaviour with occupation type and perceptions towards physical activity were analysed by day type in multiple linear regression analyses.

Results

On workdays, adults spent a mean (SD) of 4.17 (3.07) h/day in work sitting, 1.10 (1.69) h/day in transport sitting, 2.19 (1.62) h/day in leisure-time sitting, 1.53 (1.24) h/day viewing TV/DVDs, 2.19 (2.62) h/day on other screen time, and 0.97 (1.49) on non-screen time. On non-workdays, this was 0.85 (1.53) h/day in transport sitting, 3.19 (2.05) h/day in leisure-time sitting, 2.24 (1.76) h/day viewing TV/DVDs, 1.85 (1.74) h/day on other screen time, and 1.30 (1.35) on non-screen time. Time spent in sedentary behaviours differed by occupation type, with more sedentary behaviour outside of work (both sitting and entertainment time), in those with sedentary occupations, especially on workdays. Negative perceptions towards physical activity were associated with more sedentary behaviour outside of work (both sitting and entertainment time), irrespective of day type.

Conclusions

A substantial amount of waking hours was spent in different types of sedentary behaviours on workdays and non-workdays. Being sedentary at work was associated with more sedentary behaviour outside of work. Negative perceptions towards physical activity may influence the amount of time spent in sedentary behaviours. These data should help to better identify target groups in public health interventions to reduce sedentary behaviours in working adults.

Associations of breaks in sedentary time with abdominal obesity in Portuguese older adults

In older adults, sedentary time is positively associated with obesity. The manner in which it is accumulated, i.e., the number of breaks in sedentary time, might be also important. We examined the cross-sectional associations of breaks in sedentary time with abdominal obesity in 301 older adults (111 men and 190 women) aged 75.0 ± 6.8 years. Sedentary time (counts min(-1) < 100) and physical activity were objectively measured by accelerometry, worn during waking hours for at least three consecutive days. A break was defined as an interruption (≥ 100 counts min(-1) < 2020) in sedentary time while performing light intensity physical activities. Sedentary time was expressed as the number of daily breaks in sedentary time or hourly breaks in sedentary time. Abdominal obesity was defined by waist circumference (men >102 cm; women >88 cm). Using binary logistic regression analyses, the odds for abdominal obesity decreased 7 % for each additional hourly break in sedentary time in women (OR = 0.93, 95 % CI: 0.87-1.00), but not men, independently of total sedentary time and moderate-to-vigorous physical activity. The odds for abdominal obesity were 3.21 times higher (p = 0.039) for women in quartile 1 (<225 breaks day(-1)) of daily breaks in sedentary time compared to those in quartile 4 (>353 breaks day(-1)) of daily breaks in sedentary time.These findings indicate that older women who interrupt their sedentary time more frequently are less likely to present abdominal obesity. Public health recommendations regarding breaking-up sedentary time complementary to those for physical activity are likely to be relevant.

The association between different types of exercise and energy expenditure in young nonoverweight and overweight adults

With decades of trends for decreasing activity during work and travel, exercise becomes an important contributor to total physical activity (PA) and energy expenditure. The purpose of this study was to examine the contribution of different types of exercise to the variability in energy expenditure and time spent at different PA intensities in young adults. Four hundred and seventeen adults (49.9% male; 46.2 overweight/obese) between 21 and 36 years of age provided valid objective PA and energy expenditure data, assessed via the SenseWear Armband (BodyMedia Inc.). Frequency and duration of participation in various exercise types was self-reported. Weight status was based on body mass index (BMI) (kg/m(2)) with body weight and height being measured according to standard procedures. Eighty-four percent of the participants reported regular exercise engagement with no difference in participation rate by sex or BMI category. Exercise time along with sex and ethnicity explained roughly 60% of the variability in total daily energy expenditure (TDEE) while the association between exercise and time spent in moderate to vigorous PA or being sedentary was low or nonsignificant. Engagement in endurance exercise and sports contributed predominantly to the variability in energy expenditure and PA in nonoverweight participants. In overweight/obese participants engagement in resistance exercise and swimming contributed significantly to variability in TDEE. Current exercise recommendations focus primarily on aerobic exercise, but results of the present study suggest that nonweight-bearing exercises, such as resistance exercise and swimming, contribute significantly to the variability in TDEE in overweight/obese adults, which would make these types of activities viable options for exercise interventions.

Physical activity after surgically obtained weight loss: study with a SenseWear armband in subjects undergoing biliopancreatic diversion

BACKGROUND

This study aimed to understand the role of the extra load of body mass in limiting physical activity and in preventing an active lifestyle in severely obese patients.

MATERIALS AND METHODS

The study was carried out in a University Hospital setting, and investigates severely obese patients, having undergone biliopancreatic diversion (BPD) for obesity and control subjects with a body weight closely similar to that of the BPD subjects; energy intake was evaluated by alimentary interview and energy expenditure was assessed with the Body Media SenseWear® Pro armband (SWA).

RESULTS

SWA metabolic efficiency (MET) was negatively associated with body mass index values (ρ = -0.464, p < 0.01), and the SWA overall energy expenditure was very similar to the energy alimentary intake in the obese patients and in the control subjects. Among the controls, the MET mean value was higher (p < 0.05) than that observed both in obese and in BPD subjects (1.392 ± 0.211 vs. 1.149 ± 0.181 and 1.252 ± 0.284, respectively); furthermore, in comparison with the obese and the BPD groups, among the control individuals a greater number of active persons (27% vs. 0 and 7%, respectively) and a lower number of sedentary persons (27% vs. 70 and 43%, respectively) was found (p < 0.01).

CONCLUSIONS

These preliminary results suggest the reliability of SWA data in assessing energy expenditure and tend to rule out the hypothesis that in severely obese patients the extra load of body mass by itself is a main factor limiting physical activity and leading to a sedentary lifestyle.

Physical activity levels during pregnancy and gestational weight gain among women who are overweight or obese

ISSUE ADDRESSED

There is contradictory research assessing physical activity patterns during pregnancy and postpartum among women who are overweight or obese. The aim of this study was to evaluate physical activity among overweight and obese women over the course of pregnancy and the initial postpartum period.

METHODS

Three hundred and five overweight or obese pregnant women completed physical-activity questionnaires at three time points during pregnancy and at 4-months postpartum.

RESULTS

Physical activity declined between early pregnancy and 28-weeks gestation (P<0.001) and declined further at 36-weeks gestation (P<0.001) before increasing significantly at 4-months postpartum (P<0.001). However, reported activity at 4-months postpartum remained significantly lower than that reported in early pregnancy (P<0.001). There was no significant difference either cross-sectionally or for changes over pregnancy and postpartum for total levels or categories of physical activity for women with different body mass index (BMI) or gestational weight gain (GWG). BMI was the only independent predictor of the change in total physical activity over the study and GWG, with women with higher BMI having larger decline of physical activity (β=0.114, s.e.=0.750, P=0.032) and less GWG (β=-0.253, s.e.=0.063, P<0.001).

CONCLUSIONS

Physical activity declined significantly between early pregnancy and 28-weeks gestation, with a further decline to 36-weeks gestation. At 4-months postpartum, physical activity significantly increased but not to the level of that reported at early pregnancy. SO WHAT?: The promotion of appropriate physical activity should be implemented early in pregnancy and postpartum to prevent the decline in activity we have observed in overweight and obese women. Future research should also explore the barriers and enablers to women engaging in exercise during pregnancy and the postpartum period.

Maternal high fat diet consumption during the perinatal period programs offspring behavior

The environment that a developing offspring experiences during the perinatal period is markedly influenced by maternal health and diet composition. Evidence from both epidemiological studies and animal models indicates that maternal diet and metabolic status play a critical role in programming the neural circuitry that regulates behavior, resulting in long-term consequences for offspring behavior. Maternal diet and metabolic state influence the behavior of offspring directly by impacting the intrauterine environment and indirectly by modulating maternal behavior. The mechanisms by which maternal diet and metabolic profile shape the perinatal environment remain largely unknown, but recent research has found that increases in inflammatory cytokines, nutrients (glucose and fatty acids), and hormones (insulin and leptin) affect the environment of the developing offspring. Offspring exposed to maternal obesity and high fat diet consumption during development are more susceptible to developing mental health and behavioral disorders such as anxiety, depression, attention deficit hyperactivity disorder, and autism spectrum disorders. Recent evidence suggests that this increased risk for behavioral disorders is driven by modifications in the development of neural pathways involved in behavioral regulation. In particular, research indicates that the development of the serotonergic system is impacted by exposure to maternal obesity and high fat diet consumption, and this disruption may underlie many of the behavioral disturbances observed in these offspring. Given the high rates of obesity and high fat diet consumption in pregnant women, it is vital to examine the influence that maternal nutrition and metabolic profile have on the developing offspring.