Longitudinal assessment of physical activity in women undergoing Roux-en-Y gastric bypass

Levels of Physical Activity, Enjoyment, Self-Efficacy for Exercise, and Social Support Before and After Metabolic and Bariatric Surgery: a Longitudinal Prospective Observational Study

INTRODUCTION

Physical activity (PA) after metabolic and bariatric surgery (MBS) can influence weight loss, health status, and quality of life. Known mediators to participate in PA are enjoyment, self-efficacy, and social support. Little is known about PA behavior in MBS individuals. The aim of this study was to explore levels of PA and the PA mediators enjoyment, self-efficacy, and social support before and after MBS and to investigate changes over time.

METHODS

Adults scheduled to undergo MBS were recruited from a Swedish university hospital. Accelerometer-measured and self-reported PA, body weight, and PA mediators were collected at baseline and at 12 to 18 months post-surgery.

RESULTS

Among 90 individuals included, 50 completed the follow-up assessment and had valid accelerometer data. Sedentary time (minutes/day) was unchanged, but sedentary time as percentage of wear time decreased significantly from 67.2% to 64.5% (p<0.05). Time spent in light PA and total PA increased significantly from 259.3 to 288.7 min/day (p < 0.05) and from 270.5 to 303.5 min/day (p < 0.01), respectively. Step counts increased significantly from 6013 to 7460 steps/day (p < 0.01). There was a significant increase in self-reported PA, enjoyment, self-efficacy for exercise, and positive social support from family. The increase in PA mediators did not lead to a significant change in time spent in moderate to vigorous PA.

CONCLUSION

The increase in PA-mediators was not associated with an increase in moderate to vigorous PA, but the strengthened PA mediators suggest potential for an increase in moderate to vigorous PA in patients undergoing MBS.

Effects of obesity, and of weight loss following bariatric surgery, on methylation of DNA from the rectal mucosa and in cell-free DNA from blood

BACKGROUND

DNA methylation is an epigenetic mechanism through which environmental factors including nutrition and inflammation influence health. Obesity is a major modifiable risk factor for many common diseases including cardiovascular diseases and cancer. In particular, obesity-induced inflammation resulting from aberrantly-methylated inflammatory genes may drive risk of several non-communicable diseases including colorectal cancer (CRC). This study is the first to investigate the effects of weight loss induced by bariatric surgery (BS) on DNA methylation in the rectum and in cell-free DNA (cfDNA) from blood.

SUBJECTS AND METHODS

DNA methylation was quantified in rectal mucosal biopsies and cfDNA from serum of 28 participants with obesity before and 6 months after BS, as well as in 12 participants without obesity (control group) matched for age and sex from the Biomarkers Of Colorectal cancer After Bariatric Surgery (BOCABS) Study. DNA methylation of LEP, IL6, POMC, LINE1, MAPK7 and COX2 was quantified by pyrosequencing.

RESULTS

BMI decreased significantly from 41.8 kg/m2 pre-surgery to 32.3 kg/m2 at 6 months after BS. Compared with the control group, obesity was associated with lower LEP methylation in both the rectal mucosa and in cfDNA from serum. BS normalised LEP methylation in DNA from the rectal mucosa but not in cfDNA. BS decreased methylation of some CpG sites of LINE1 in the rectal mucosal DNA and in cfDNA to levels comparable with those in participants without obesity. Methylation of POMC in rectal mucosal DNA was normalised at 6 months after BS.

CONCLUSION

BS reversed LINE1, POMC and LEP methylation in the rectal mucosa of patients with obesity to levels similar to those in individuals without obesity. These findings support current evidence of effects of BS-induced weight loss on reversibility of DNA methylation in other tissues. The DNA methylation changes in the rectal mucosa shows promise as a biomarker for objective assessment of effects of weight loss interventions on risk of cancer and other diseases.

Associations of changes in physical activity and sedentary time with weight recurrence after bariatric surgery: a 5-year prospective study

BACKGROUND

Increasing physical activity and limiting sedentary time may minimize weight recurrence after bariatric surgery. However, few studies have evaluated potential associations of objectively-measured physical activity and sedentary time with post-surgical weight recurrence over time.

AIMS

To evaluate associations of change in physical activity and sedentary time with weight recurrence after bariatric surgery.

METHODS

Participants from the Oslo Bariatric Surgery Study, a prospective cohort study, wore an ActiGraph monitor for seven days at 1- and 5 years after surgery to assess daily physical activity and sedentary time. Participants' weight was measured at in-person clinic visits. Chi-square Test and Paired-samples T-test evaluated group differences and change over time, while Pearson's Correlation, multiple logistic and linear regression investigated associations between variables.

RESULTS

Five years after surgery 79 participants (70.5% response rate, 81% female) (mean (sd) age: 54.0 (±9.3), BMI: 32.1 (±4.7)) had valid monitor data. Participants increased their sedentary time (71.4 minutes/day (95% CI: 54.2-88.6, p = <0.001)) and reduced daily steps (-1411.1 (95% CI: 737.8-208.4), p = <0.001), light physical activity (-54.1 min/day (95% CI: 40.9-67.2, p = <0.001)), and total physical activity (-48.2 (95% CI: 34.6-63.3), p = <0.001) from 1- to 5 years after surgery. No change was found for moderate-to-vigorous intensity physical activity. No associations were found between changes in steps, physical activity or sedentary time and weight recurrence.

CONCLUSION

Participants increased sedentary time and decreased light- and total physical activity between 1- and 5 years post-surgery. Overall, changes in physical activity and sedentary time were not associated with weight recurrence. Interventions to help patients increase physical activity and limit sedentary time after bariatric surgery are needed.

Exercise/Physical Activity in Individuals with Type 2 Diabetes: A Consensus Statement from the American College of Sports Medicine

ABSTRACT

This consensus statement is an update of the 2010 American College of Sports Medicine position stand on exercise and type 2 diabetes. Since then, a substantial amount of research on select topics in exercise in individuals of various ages with type 2 diabetes has been published while diabetes prevalence has continued to expand worldwide. This consensus statement provides a brief summary of the current evidence and extends and updates the prior recommendations. The document has been expanded to include physical activity, a broader, more comprehensive definition of human movement than planned exercise, and reducing sedentary time. Various types of physical activity enhance health and glycemic management in people with type 2 diabetes, including flexibility and balance exercise, and the importance of each recommended type or mode are discussed. In general, the 2018 Physical Activity Guidelines for Americans apply to all individuals with type 2 diabetes, with a few exceptions and modifications. People with type 2 diabetes should engage in physical activity regularly and be encouraged to reduce sedentary time and break up sitting time with frequent activity breaks. Any activities undertaken with acute and chronic health complications related to diabetes may require accommodations to ensure safe and effective participation. Other topics addressed are exercise timing to maximize its glucose-lowering effects and barriers to and inequities in physical activity adoption and maintenance.

Physical activity in women attending a dissonance-based intervention after Roux-en-Y Gastric Bypass: A 2-year follow-up of a randomized controlled trial

Background

The majority of Roux-en-Y gastric bypass (RYGB) patients are not sufficiently physically active post-surgery, yet little support from the Swedish healthcare system is offered. We investigated if a dissonance-based group intervention, aiming to increase health-related quality of life after surgery, had any effect on patients’ physical activity two years post-RYGB.

Methods

Women undergoing RYGB surgery were recruited from five Swedish hospitals and randomized to intervention or control group (standard post-surgery care). The dissonance-based intervention was conducted three months post-RYGB and consisted of four group sessions, each with a specific topic, of which one addressed physical activity. ActiGraph GT3X+ accelerometers were used to measure physical activity at pre-RYGB, one- and two-years post-surgery.

Results

At pre-RYGB, 259 women were recruited and randomized (intervention n = 156 and control n = 103). Participants had a mean age of 44.7 years (SD 10.3) and pre-RYGB body mass index of 40.8 (SD 4.5) kg/m². At two-years follow-up, 99 participants (63.5%) in intervention group and 68 (66.0%) in control group had valid accelerometer-measurements. Pre- to post-surgery increases were seen in all physical activity outcomes, but no statistically significant differences between the groups were observed at the two-years follow-up, and intervention effects were poor (d = 0.02–0.35).

Conclusion

To our knowledge, this is the first dissonance-based intervention targeting women undergoing RYGB surgery. At two-years follow-up, we did not observe any differences in physical activity levels between the intervention group and control group.

Trial registration number: ISRCTN16417174.

Patterns of Change in Device-Based Physical Activity and Sedentary Time Following Bariatric Surgery: a Longitudinal Observational Study

PURPOSE

The aim of this study is to investigate changes in physical activity (PA) and sedentary time (ST) over 12 months following bariatric surgery.

METHODS

Pre-surgery and at 3, 6, 9, and 12 months post-surgery, wearable devices were used to measure PA at different intensities, grouped according to energy expenditure and daily step count, and ST. Measures were also collected of weight and self-efficacy for exercise. Pre- and 12 months post-surgery, measures were collected of body composition and cardiovascular fitness.

RESULTS

Thirty adults scheduled for bariatric surgery were recruited (20 females, 44.1 [range, 22.0 to 65.0] years, body mass index 39.6 [range, 30.9 to 50.9] kg/m²). When compared to pre-surgery measures, over the 12 months post-surgery, there were no changes in the percentage of waking hours (mean [95% CI]) spent in ST (- 2% [- 6 to 3]), light intensity PA (1% [- 3 to 5]), and moderate-to-vigorous intensity PA (1% [- 1 to 3]). At all time points, participants spent most (> 70%) of their waking hours accumulating ST, with little time spent in light intensity PA (~ 21%) and almost no time in moderate-to-vigorous intensity PA (~ 5%). Step count and cardiovascular fitness were also unchanged. There were significant changes in weight, self-efficacy for exercise, and body composition.

CONCLUSIONS

Although bariatric surgery resulted in substantial weight loss and improved self-efficacy for exercise, it was insufficient to effect change in PA, ST or cardiovascular fitness. Complementing surgical intervention with behavioral interventions may optimize change in PA and ST.

Long-term effects of physical activity prescription after bariatric surgery: A randomized controlled trial

PURPOSE

This study examined the effects of physical activity prescription (PAP) in patients after gastric bypass surgery. Patients' physical activity (PA) levels and outcomes were followed over their first postoperative year.

METHODS

Patients slated for bariatric surgery were randomized to a control group (n = 64) (basic information about postoperative PA) or an intervention group (n = 57) (also received physical therapist-prescribed PAP). Outcome measures were self-reported PA/exercise and sedentary time; and weight, waist circumference, blood pressure, and blood lipids; recorded pre-operatively and at 2, 6, and 12 months postoperatively. Follow-ups were conducted by nurses/dieticians. Trial registration: "Research and Development in Sweden" number 107371.

RESULTS

There were no differences between the groups except for higher level of PA (579 vs. 182 minutes/week) six months after surgery (p = .046) and a larger decrease in cholesterol (-24 vs. -8%) after a year (p = .017) in the intervention group. Patients in both groups lost considerable weight, had reduced waist circumference, and increased PA (p < .001).

CONCLUSION

Although marked differences between groups were not observed over one year, the intervention group increased its PA 6-months postoperatively, but not at other time points. Whether long-term outcomes of PAP use are more robust with physical therapist participation across follow-ups warrants study.

Physical Activity Level, Sedentary Time, and Weight Regain After Bariatric Surgery in Patients Without Regular Medical Follow-up: a Cross-Sectional Study

PURPOSE

The impact of regular exercises or physical activity (PA) on weight of bariatric patients need to be elucidated. We investigated PA levels, sedentary time (ST), and weight regain on these patients who were without regular medical follow-up before recruitment. Moreover, we investigated correlation and concordance between self-reported and objective measures in moderate-to-vigorous PA (MVPA) and ST.

MATERIALS AND METHODS

We invited 132 patients previously subjected to a bariatric procedure to a medical appointment in our unit and proposed them to be volunteers. Ninety patients, aged 42 ± 8 years and BMI 32.9 ± 6.6 kg/m², entered the study and were allocated into groups according to time since surgery < or ≥5 years (G5- or G5+, respectively). They were further assigned into low or high rates of weight regain (RWR; cutoff 20%). PA and ST were measured by International PA Questionnaire (IPAQ) and ActiGraph GT3X+ accelerometer.

RESULTS

In G5- group, PA and ST were similar between low and high RWR. In G5+ group, MVPA time, number of steps/day, percent of patients somewhat active, and 30-60 min/day of MVPA were statistically higher in those with low RWR. Of note, measures of MVPA < 30 min/day occurred more frequently in those with high RWR. MVPA and ST self-reported vs. objective measures were correlated (P < 0.001). Nevertheless, there was no concordance between these measures (P > 0.05).

CONCLUSIONS

Low level of PA and longer ST occurred more frequently in those with high RWR and longer time since surgery. Although well-correlated, any concordance between IPAQ and accelerometer measures was noted.

Bariatric Surgery: Consequences on Functional Capacities in Patients With Obesity

INTRODUCTION

Bariatric surgery leads to loss of fat and fat-free mass (FFM). To preserve FFM it is recommended that weight loss interventions are accompanied by physical activity. However, it remains unknown if functional capacities spontaneously improve after a substantial weight loss. Study's aim was to assess the effect of bariatric surgery on strength, functional capacities and quality of life of participants with a body mass index (BMI) ≥ 35 kg/m².

METHOD

Anthropometric parameters (weight, BMI, waist circumference), physical functions (quadriceps strength, walking capacity, spatio-temporal gait parameters, dynamic balance, lower limb power) and quality of life were assessed before and at three months after the bariatric surgery in 33 individuals who did not follow any physical activity program.

RESULTS

The anthropometric parameters, quality of life and three functional abilities (walking capacity, normal gait speed and lower limb power) improved significantly three months post-surgery. In contrast, fast gait speed, absolute strength, normalized strength, and dynamic balance did not improve.

DISCUSSION

A massive weight loss should be accompanied by an exercise program aiming to maintain FFM and to enhance muscle strength and balance. Such a program might also enhance functional capacities and help to sustain the weight loss over time.

Physical activity, musculoskeletal disorders, sleep, depression, and quality of life before and after bariatric surgery

Objectives

This study aims to evaluate physical activity, sleep, depression, quality of life, and musculoskeletal problems pre- and postoperatively in morbidly obese patients who underwent bariatric surgery and analyze the factors that are strongly associated with physical activity.

Patients and methods

This prospective study conducted between January 2016 and May 2017 included 27 patients (4 males, 23 females; mean age 37.1±10.4 years; range, 18 to 52 years) who underwent bariatric surgery and 20 healthy controls (3 males, 17 females; mean age 32.0±5.7 years; range, 26 to 46 years). All patients were evaluated by using the short form of International Physical Activity Questionnaire (IPAQ), Pittsburgh Sleep Quality Index (PSQI), Beck Depression Inventory (BDI), and short form 36 (SF-36). Patients were evaluated for regional musculoskeletal pain including back, waist, hip, knee, ankle, heel, and metatarsal pain using Visual Analog Scale. Presence of pes planus was recorded. The examinations and tests performed in the preoperative period were repeated at postoperative six months and the results were compared with the control group.

Results

The body mass index was 46.2±5.2 kg/m² preoperatively and 33.8±5.0 kg/m² postoperatively (p<0.001). The total IPAQ was 345.4±172.8 metabolic equivalent (MET)-min/week preoperatively and 672.8±227.8 MET-min/week postoperatively (p<0.001). Pittsburgh Sleep Quality Index was 7.6±3.0 preoperatively and 3.5±2.4 postoperatively, whereas BDI was 20.2±8.5 preoperatively and 9.9±7.4 postoperatively. The results were statistically significant (p<0.001, p<0.001, respectively). A statistically significant improvement was found in all subsections of the SF-36. Pre- and postoperative results of the 27 patients were compared with those of the control group.

Conclusion

Obesity is significantly associated with joint pain, physical function impairment, depression, and sleep disorders. Significant weight loss after bariatric surgery improves functional recovery and patient's psychology in a short time.

Physical Activity, Sedentary Behavior, and Sleep Before and After Bariatric Surgery and Associations with Weight Loss Outcome

PURPOSE

Physical activity, sedentary behavior, and sleep have been linked to the likelihood of maintaining healthy body weight. This study aimed to determine objectively measured movement behaviors before and up to 18 months after bariatric surgery and to investigate whether preoperative levels of these movement behaviors and potential changes of these behaviors were associated with changes in body weight and boy composition.

MATERIALS AND METHODS

Accelerometer determined total physical activity, moderate-to-vigorous physical activity (MVPA), light physical activity, sedentary behavior, and sleep (for six consecutive days and seven nights) were assessed approximately 3 months and 1-2 weeks before surgery as well as 6 and 18 months after surgery (n = 41). Body weight and body composition (waist circumference, fat mass, and fat-free mass) were determined at each visit.

RESULTS

Mean weight loss 18 months after surgery was 42.0 ± 1.9 kg. There were no pre- to postoperative improvements in physical activity, sedentary behavior, or sleep. However, greater increases in levels of total physical activity and time spent in MVPA from 3 months before to 6 months after surgery predicted better weight loss and larger reductions in fat mass and waist circumference. Unexpectedly, a lower level of physical activity and a higher level of sedentary behavior before surgery predicted better weight loss outcomes.

CONCLUSION

Objectively measured movement behaviors do not improve after bariatric surgery despite a substantial weight loss. However, increasing total physical activity and/or more time spent in MVPA after surgery may increase weight loss and lead to favorable changes in body composition.

The Relationship Between Energy Intake and Weight Loss in Bariatric Patients

INTRODUCTION

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.

OBJECTIVE

To explore the relationship between total energy intake and % total body weight loss (%TBWL) over a period of 4 years post-surgery.

METHODS

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).

RESULTS

%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).

CONCLUSION

This study showed a higher decrease in energy intake to be related with a higher %TBWL.

Changes in Cardiorespiratory Fitness After Gastric Bypass: Relations with Accelerometry-Assessed Physical Activity

BACKGROUND

Exercise training optimizes cardiorespiratory fitness (CRF) after bariatric surgery, but the effect of spontaneous physical activity is not well known. This study aimed to objectively quantify changes in CRF and habitual physical activity 6 months after bariatric surgery and to examine whether change in CRF was related to change in physical activity.

METHODS

Secondary analyses were performed on data from women who underwent Roux-en-Y gastric bypass (RYGB) between 2010 and 2014. Measurements were performed before and 6 months after RYGB and included V̇O₂peak (graded maximal exercise test on a cycle ergometer), habitual physical activity (Actigraph GT3x accelerometer worn during 7 days), and body composition (DXA absorptiometry). Changes after RYGB were analyzed using Wilcoxon signed-rank test. Relations between change in CRF and change in physical activity were analyzed with Spearman correlations adjusted on age and preoperative BMI.

RESULTS

Forty-five women (median [P₂₅-P₇₅] age, 43.0 [38.0-51.0] year; BMI, 42.6 [40.0-45.5] kg/m²) were included. Mean (SD) weight loss 6 months after RYGB was - 27.5 (7.9) kg (P < 0.001). Absolute V̇O₂peak decreased by 0.35 (0.50) L/min (P < 0.001) and relative V̇O₂peak tended to increase by 1.7 (5.3) mL/kg/min (P = 0.06), both with large inter-individual variability. Based on objective accelerometry data, daily steps and moderate-to-vigorous physical activity increased by 1275 (3164) steps/day and 7.6 (19.3) min/day, respectively (both P < 0.05). Change in absolute V̇O₂peak was positively related to change in moderate-to-vigorous physical activity (r = 0.35; P = 0.03).

CONCLUSIONS

The decrease in absolute CRF observed 6 months after RYGB might be prevented by increasing habitual physical activity.

TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT01113996.

Changes in Bariatric Patients' Physical Activity Levels and Health-Related Quality of Life Following a Postoperative Motivational Physical Activity Intervention

PURPOSE

Self-determination theory (SDT) has been widely used as a useful motivational framework for improving long-term adherence to physical activity (PA) and health-related quality of life (HRQoL). The aim of this study was to examine the effects of a 6-month motivational PA intervention (MPAI) on bariatric patients' PA levels and HRQoL from pre-surgery to the end of the MPAI (7 months post-surgery). Additionally, a re-test was performed 13 months post-surgery.

METHODS

A total of 40 participants undergoing sleeve gastrectomy were assigned to a 6-month MPAI or to a control group. The MPAI was based on techniques and messages from SDT. At baseline and post-intervention measures, both groups wore accelerometers for one week and completed the SF-36 questionnaire.

RESULTS

A total of 32 participants (78.1% female) completed all measures and were included in the final analyses. PA levels did not significantly differ between groups as a consequence of the intervention. Clinically significant differences (d ≥ 0.5) favoring the MPAI group were found for SF-36 domains of bodily pain (at pre-surgery, increasing at 7 and 13 months post-surgery), general health and vitality (7 months post-surgery), and physical functioning and physical component score (both 7 and 13 months post-surgery). Social functioning also showed clinically significant differences favoring the MPAI group at pre-surgery, increasing at 7 months post-surgery. These differences disappeared at 13 months post-surgery.

CONCLUSIONS

SDT-based PA interventions could enhance several dimensions of bariatric patients' HRQoL after surgery. Further research is needed to understand what motivational processes are key aspects to promote PA participation in these patients.

Accelerometer-measured versus self-reported physical activity levels in women before and up to 48 months after Roux-en-Y Gastric Bypass

Background

Roux-en-Y Gastric Bypass (RYGB) patients overestimate their time spent in moderate-to-vigorous physical activity (MVPA) to a greater extent post-surgery than pre-surgery. However, there is no data on discrepancy between self-reported and accelerometer-measured MVPA beyond nine months post-RYGB. The aim was to investigate how the duration of MVPA (main outcome) differs when comparing a self-administered questionnaire to accelerometer-data from pre-surgery and up to 48 months post-RYGB.

Methods

Twenty-six (38%) RYGB-treated women with complete data from the original cohort (N = 69) were included. Participants were recruited from five Swedish hospitals. Mean pre-surgery BMI was 38.9 (standard deviation (SD) = 3.4) kg/m² and mean age 39.9 (SD = 6.5) years. MVPA was subjectively measured by a self-administered questionnaire and objectively measured by the ActiGraph GT3X+ accelerometer at 3 months pre-RYGB and 9- and 48 months post-RYGB. Means and SD were calculated at 3 months pre- and 9- and 48 months post-RYGB. We calculated the P-values of the differences with Wilcoxon Signed-Rank test. For correlations between the self-administered questionnaire and the accelerometers, Spearman’s rank correlation was used.

Results

Participants significantly overestimated (i.e. self-reported more time spent in MVPA compared to accelerometry) their MVPA in a higher degree post- compared to pre-RYGB surgery. Compared to pre-surgery, self-reported MVPA increased with 46.9 and 36.5% from pre- to 9- and 48 months, respectively, whereas changes were a 6.1% increase and 3.5% decrease with accelerometers. Correlations between self-reported and accelerometer-measured MVPA-assessments were poor at all measurement points (r = 0.21–0.42) and only significant at 48 months post-RYGB (P = 0.032).

Conclusions

The discrepancy between self-reported and objectively assessed MVPA within the same individual is greater up to 48 months post-RYGB compared to before surgery. To help bariatric patients understand and hopefully increase their physical activity behaviors post-surgery, objective measures of physical activity should be used.

To be or not to be active - a matter of attitudes and social support? Women's perceptions of physical activity five years after Roux-en-Y Gastric Bypass surgery

Purpose: Despite positive health advantages of post-surgery physical activity (PA) for bariatric surgery patients, the majority is not sufficiently physically active. The aim was to explore women’s perceptions and experiences concerning PA five years after Roux-en-Y Gastric Bypass (RYGB) surgery.

Methods: Eleven women were interviewed five years post-surgery. Grounded Theory approach was applied.

Results: The core-category “Attitudes and surrounding environment influence activity levels” includes three attitudes towards PA: “Positive attitudes”, “Shifting attitudes” and “Negative attitudes”. Participants with a positive attitude were regularly physically active, felt supported and proud of their achievements. Contrary, participants with a negative attitude didn’t prioritize PA, didn’t feel supported and saw no need or benefit of PA. Some participants revealed an on-off behaviour, hovering between the attitudes of vigorous PA and sedentary lifestyle, without sustainable balance. The majority mostly viewed PA as a mean to lose weight.

Conclusion: The level of perceived post-surgery PA was related to the participants’ attitudes towards PA and whether or not they had a supportive environment. These findings might explain why bariatric surgery patients often fail to be sufficiently active post-surgery, and highlight the need for prolonged support and motivational interventions to promote sustainable PA post-bariatric surgery.

Roux-en-Y gastric bypass surgery restores insulin-mediated glucose partitioning and mitochondrial dynamics in primary myotubes from severely obese humans

Background/Objectives:

Impaired insulin-mediated glucose partitioning is an intrinsic metabolic defect in skeletal muscle from severely obese humans (BMI ≥ 40 kg/m²). Roux-en-Y gastric bypass (RYGB) surgery has been shown to improve glucose metabolism in severely obese humans. The purpose of the study was to determine the effects of RYGB surgery on glucose partitioning, mitochondrial network morphology, and markers of mitochondrial dynamics skeletal muscle from severely obese humans.

Subject/Methods:

Human skeletal muscle cells were isolated from muscle biopsies obtained from RYGB patients (BMI = 48.0 ± 2.1, n=7) prior to, 1-month and 7-months following surgery and lean control subjects (BMI = 22.4 ± 1.1, n=7). Complete glucose oxidation, non-oxidized glycolysis rates, mitochondrial respiratory capacity, mitochondrial network morphology and regulatory proteins of mitochondrial dynamics were determined in differentiated human myotubes.

Results:

Myotubes derived from severely obese humans exhibited enhanced glucose oxidation (13.5%; 95%CI [7.6, 19.4], P = 0.043) and reduced non-oxidized glycolysis (−1.3%; 95%CI [−11.1, 8.6]) in response to insulin stimulation at 7-months after RYGB when compared to the pre-surgery state (−0.6%; 95%CI [−5.2, 4.0] and 19.5%; 95%CI [4.0, 35.0], P =0.006), and were not different from the lean controls (16.7%; 95%CI [11.8, 21.5] and 1.9%; 95%CI [−1.6, 5.4], respectively). Further, number of fragmented mitochondria and Drp1(Ser⁶¹⁶) phosphorylation and were trended to reduced/reduced (0.0104, 95%CI [0.0085, 0.0126], P = 0.091 and 0.0085, 95%CI [0.0068, 0.0102], P = 0.05) in myotubes derived from severely obese humans at 7-months after RYGB surgery in comparison to the pre-surgery state. Finally, Drp1(Ser⁶¹⁶) phosphorylation was negatively correlated with insulin-stimulated glucose oxidation (r = −0.49, P = 0.037).

Conclusion/Interpretation:

These data indicate that an intrinsic metabolic defect of glucose partitioning in skeletal muscle from severely obese humans is restored by RYGB surgery. The restoration of glucose partitioning may be regulated through reduced mitochondrial fission protein Drp1 phosphorylation.

Changes in Physical Activities and Body Composition after Roux-Y Gastric Bypass Surgery

PURPOSE

Given the importance of physical activities for health outcomes, it is still unclear whether bariatric surgery per se and the standard care after surgery would result in an increase of physical activity level. This study aimed to determine physical activities preoperatively and at 6 and 12 months postoperatively among female patients who underwent bariatric surgery, and to investigate its relationship with body composition changes.

MATERIAL AND METHODS

Thirty-four women who had Roux-Y gastric bypass (RYGB) surgery completed the study. Physical activity was measured objectively for 7 consecutive days by using an ActiGraph GT3X+ accelerometer. Body composition was estimated by using multifrequency bioimpedance analysis.

RESULTS

The percentage of time spent in moderate-to-vigorous physical activity (MVPA) changed significantly from preoperatively to 6 months postoperatively; however, no difference was observed at 12 months. No significant changes were detected for other physical activity variables. Multivariable regression analysis suggested that the percentage of time spent in sedentary activity was associated with fat-free mass loss at 6 months (β = - 0.323; 95% CI = - 0.649 to 0.003) and 12 months (β = - 0.510; 95% CI = - 0.867 to - 0.154) postoperatively.

CONCLUSION

The overall MVPA increased at 6 months post-RYGB surgery; however, this change was not maintained at 12 months. Despite the considerable body mass loss postoperatively, most of the subjects were classified as being physically inactive and did not change their sedentary behavior. These findings indicate that female patients undergoing bariatric surgery should be encouraged to increase their physical activity level.

Physical fitness and physical activity in women with obesity: short term effects of sleeve gastrectomy

INTRODUCTION

Introduction: the increase on prevalence of obesity has been linked to a higher number of bariatric surgeries, being sleeve gastrectomy (SG) the most frequent bariatric procedures in the world. However, there are few studies that determine the impact of SG on health's determinants such as physical fitness (PF) and physical activity (PA). Objectives: to describe the changes in PF and PA of patients after SG. Methods: twenty-three women with obesity (mean 36.1 ± 11.1 years old and body mass index [BMI] of 35.1 ± 3.4 kg/m2) were evaluated preoperatively to SG and at one and three months after surgery. An assessment of PF was conducted, including handgrip (HGS) and quadriceps muscle strength (QMS) with dynamometers and cardiorespiratory fitness (CRF) with an ergospirometer. PA was assessed with a three-axis accelerometer. Results: the absolute VO2 peak decreased after the first and third month (p < 0.001) post SG. The VO2 peak relative to body weight showed an increase from baseline after the SG (p = 0.002). After SG, there was a reduction in absolute values for HGS and QMS (p < 0.001) and an increase in relative HGS after three months post-surgery compared to preoperative (p = 0.011), without changes in relative QMS (p = 0.596). No changes in PA were observed. Conclusions: after SG, there is a short term decline on PF when it is expressed on absolute values. However, when it is expressed in relative terms to body weight, some components of PF improve, while others showed no change. There was no modification in PA levels of the participants.

Influence of Energy Balance on the Rate of Weight Loss Throughout One Year of Roux-en-Y Gastric Bypass: a Doubly Labeled Water Study

OBJECTIVE

To investigate the influence of changes in energy balance and body composition on the rate of weight loss throughout 1 year of Roux-en-Y gastric bypass.

METHODS

Variables were collected pre-, 6, and 12 months (M) post-surgery from 18 women (BMI ≥ 40 and ≤ 50 kg m^-2, 20 to 45 years). Total energy expenditure (TEE_m), fat-free mass (FFM), and fat mass (FM) were measured by doubly labeled water. Self-reported energy intake (EI_sr) was obtained from three non-consecutive food diaries. Metabolic adaptation was assessed via deviations from TEE predictive equation, and the calculated energy intake (EI_c) via the sum of TEE and change in body stores.

RESULTS

BMI significantly decreased (mean ± SD) from 45 ± 2 kg m^-2 to 32 ± 3 kg m^-2 at 6 M, and to 30 ± 3 kg m^-2 at 12 M after surgery. The TEE_m reduced significantly at both time points when compared with pre-surgery (6 M: - 612 ± 317 kcal day^-1; 12 M: - 447 ± 516 kcal day^-1). At 6 M, a metabolic adaptation was observed and the energy balance was - 1151 ± 195 kcal day^-1, while at 12 M it was - 332 ± 158 kcal day^-1. Changes in the values of TEE_m were associated with changes in body weight at 12 M post-surgery. A significant underreporting was observed for EI_sr (1057 ± 385 kcal day^-1) vs. EI_c (2083 ± 309 kcal day^-1) at 12 M post-operative.

CONCLUSION

The higher rate of weight loss at 6 M post-surgery was a response to energy imbalance, which was caused by high restriction in energy intake even with the presence of metabolic adaptation at this time. The EI_sr was not sufficiently accurate to assess the energy consumption of this population.

REGISTRATION OF CLINICAL TRIALS (OBSERVATIONAL STUDY)

Brazilian Clinical Trials Registry: RBR-8k5jsj. Universal Trial Number: U1111-1206-0858.

Meta-analysis of the effect of bariatric surgery on physical activity

BACKGROUND

Obesity leads to impairment of physical activity as measured by an inability to perform activities of daily living. Literature on the effect of bariatric surgery on physical activity is conflicting.

OBJECTIVE

The aim of this study was to perform a meta-analysis of the effect of bariatric surgery on physical activity from studies employing objective measurement and self-reporting of physical activity before and after bariatric surgery.

METHODS

Bibliographic databases were searched systematically for relevant literature until December 31, 2018. Studies employing objective and self-reported measurement of physical activity were included. Study quality was assessed using Risk of Bias in Nonrandomized Studies - of Interventions tool. Meta-analysis was performed using random effects model and presented as standardized mean difference (SMD) with 95% confidence intervals (CI).

RESULTS

Twenty studies identified 5886 patients suitable for the analysis. Physical activity showed significant improvement at 0-6 months (SMD: .50; 95% CI: .25-.76; P = .0001), >6-12 months (SMD: .58; 95% CI: .26-.91; P = .0004), and >12-36 months (SMD: .82; 95% CI: .27-1.36; P = .004) after bariatric surgery. Self-reported assessment after bariatric surgery showed significant improvement at 0-6 months (SMD: .65; 95% CI: .29-1.01; P = .0004), >6 to 12 months (SMD: .53; 95% CI: .18-.88; P = .003), and >12-36 months (SMD: .51; 95% CI: .46-.55; P < .00001). Objective assessment after bariatric surgery did not show improvement at 0-6 months (SMD: .31; 95%CI:-.05-.66; P = .09), but showed significant improvement at >6-12 months (SMD: .85; 95% CI:-.07-1.62; P = .03), and >12-36 months (SMD: 1.99; 95% CI: 1.13-2.86; P < .00001) after bariatric surgery.

CONCLUSIONS

Bariatric surgery improves physical activity significantly in a population with obesity up to 3 years after surgery. Objective measurement of physical activity does not show significant improvement within 6 months of bariatric surgery but begins to improve at >6 months. Self-reported measurement of physical activity begins to show improvement within 6 months of a bariatric procedure.

Meeting physical activity recommendations is associated with health-related quality of life in women before and after Roux-en-Y gastric bypass surgery

PURPOSE

Meeting physical activity (PA) recommendations is positively associated with health-related quality of life (HRQoL), but it is still unclear whether PA (specifically objectively measured) is associated with HRQoL in bariatric surgery candidates, both before and after surgery. Thus, the aim of this study was to examine the cross-sectional association between meeting objectively measured PA recommendations and HRQoL before and after Roux-en-Y gastric bypass (RYGB) surgery.

METHODS

Sixty-six women undergoing RYGB with pre-surgery and 62 women with post-surgery valid PA and HRQoL data were included from the control group of a RCT study aiming at improving HRQoL and PA post-RYGB surgery. Measures before and 12 months after RYGB included the Short Form Health Survey (SF-36) and objectively measured PA, sedentary time (ST), and step counts with GT3X+ accelerometers. Multiple linear regression models were used to analyze the associations between PA and HRQoL.

RESULTS

Participants who engaged in more than 150 min of moderate to vigorous PA (MVPA)/week (PA recommendations) had considerably higher SF-36 scores (HRQoL) than those who did not, both pre and 12-month post-surgery, with greatest difference in the subscale bodily pain, 15.5 (p = 0.021) higher score (higher scores means less pain) pre-surgery and a 19.7 (p = 0.004) higher score post-surgery. Higher LPA and step counts and lower ST also showed positive associations in some of the subscales of SF-36.

CONCLUSIONS

Meeting the PA recommendations and overall engaging in more PA was associated with higher HRQoL, pre-, and post-RYGB surgery, highlighting the importance of PA both pre- and post-surgery.

Effects of a Pre-surgery Supervised Exercise Training 1 Year After Bariatric Surgery: a Randomized Controlled Study

BACKGROUND

We have previously reported on the benefits of Pre-Surgical Exercise Training (PreSET) on physical fitness and social interactions in subjects awaiting bariatric surgery (BS). However, data are needed to know whether these benefits are maintained post-BS.

OBJECTIVES

The purpose of this paper was to evaluate the effect of PreSET on physical activity (PA) level, physical fitness, PA barriers, and quality of life (QoL) 1 year (1-Y) after BS.

METHODS

Of the 30 participants randomized into two groups (PreSET and usual care), 25 were included in the final analysis. One year after BS, time spent in different PA intensities and number of steps were assessed with an accelerometer. Before BS and until 1-Y after BS, physical fitness was assessed with symptom-limited cardiac exercise test, 6-min walk test (6MWT), and sit-to-stand, half-squat, and arm curl tests. QoL, PA barriers, and PA level were evaluated with questionnaires.

RESULTS

The number of steps (7460 vs 4287) and time spent in light (3.2 vs 2.2 h/day) and moderate (0.6 vs 0.3 h/day) PA were higher in the PreSET group 1-Y after BS. The changes in 6MWT heart cost (1.3 vs 0.6 m/beats/min), half-squat test (38.8 vs 10.3 s), and BMI (- 16.8 vs - 13.5 kg/m²) were significantly greater in the PreSET group compared to those in the usual care group. No other significant difference between groups was observed.

CONCLUSION

The addition of the PreSET to individual lifestyle counseling seems effective to improve PA level and submaximal physical fitness 1-Y after BS. Studies with larger cohorts are now required to confirm these results. The trial was registered at clinicaltrials.gov (NCT01452230).

Multi-sensor ecological momentary assessment of behavioral and psychosocial predictors of weight loss following bariatric surgery: study protocol for a multicenter prospective longitudinal evaluation

BACKGROUND

Bariatric surgery is currently the most effective strategy for producing significant and durable weight loss. Yet, not all patients achieve initial weight loss success and some degree of weight regain is very common, sometimes as early as 1-2 years post-surgery. Suboptimal weight loss not fully explained by surgical, demographic, and medical factors has led to greater emphasis on patient behaviors evidenced by clinical guidelines for appropriate eating and physical activity. However, research to inform such guidelines has often relied on imprecise measures or not been specific to bariatric surgery. There is also little understanding of what psychosocial factors and environmental contexts impact outcomes. To address research gaps and measurement limitations, we designed a protocol that innovatively integrates multiple measurement tools to determine which behaviors, environmental contexts, and psychosocial factors are related to outcomes and explore how psychosocial factors/environmental contexts influence weight. This paper provides a detailed description of our study protocol with a focus on developing and deploying a multi-sensor assessment tool to meet our study aims.

METHODS

This NIH-funded prospective cohort study evaluates behavioral, psychosocial, and environmental predictors of weight loss after bariatric surgery using a multi-sensor platform that integrates objective sensors and self-report information collected via smartphone in real-time in patients' natural environment. A target sample of 100 adult, bariatric surgery patients (ages 21-70) use this multi-sensor platform at preoperative baseline, as well as 3, 6, and 12 months postoperatively, to assess recommended behaviors (e.g., meal frequency, physical activity), psychosocial indicators with prior evidence of an association with surgical outcomes (e.g., mood/depression), and key environmental factors (e.g., type/quality of food environment). Weight also is measured at each assessment point.

DISCUSSION

This project has the potential to build a more sophisticated and valid understanding of behavioral and psychosocial factors contributing to success and risk after bariatric surgery. This new understanding could directly contribute to improved (i.e., specific, consistent, and validated) guidelines for recommended pre- and postoperative behaviors, which could lead to improved surgical outcomes. These data will also inform behavioral, psychosocial, and environmental targets for adjunctive interventions to improve surgical outcomes.

TRIAL REGISTRATION

Registered trial NCT02777177 on 5/19/2016.

Effects of 6 months supervised physical training on muscle strength and aerobic capacity in patients undergoing Roux-en-Y gastric bypass surgery: a randomized controlled trial

Obesity and physical inactivity are major health problems. Roux-en-Y gastric bypass (RYGB) surgery results in significant weight loss and reduces obesity-related morbidity and mortality. Physical activity lowers the risk of cardiovascular disease and premature death. The aims of this study were to elucidate the effects of RYGB followed by 6 months of supervised physical training on physical capacity. In a randomized controlled trial, 60 participants eligible for RYGB were randomized 6 months post-surgery to either two weekly physical training sessions for 26 weeks (INT) or a control group (CON). Aerobic capacity (VO₂ max), muscle strength (MS) of the shoulder and hip and physical function were measured pre-surgery and 6, 12 and 24 months post-surgery. RYGB per se decreased MS in all tested muscle groups, had no effects on VO₂ max but improved physical function. After the intervention, INT had a significant 0.33 L min^-1 increase in VO₂ max compared to CON (95% CI: 0.07-0.57, P = 0.013). Furthermore, MS in the hip adductor increased significantly with 13 N (95% CI: 3.6-22.4, P = 0.007) and a between-group difference was found in the Stair Climb Test (0.46 repetitions [95% CI: 0.02-0.91, P = 0.042]). The effects were not maintained at follow-up. Supervised physical training following RYGB improved VO₂ max, hip MS and physical function, but the positive effects were not maintained at follow-up. While activities of daily life may become easier as a result of RYGB, the observed extensive post-operative loss of MS requires more attention to increase the patient's physical capacity prospectively.

A dissonance-based intervention for women post roux-en-Y gastric bypass surgery aiming at improving quality of life and physical activity 24 months after surgery: study protocol for a randomized controlled trial

Background

Roux-en-Y gastric bypass (RYGB) surgery is the most common bariatric procedure in Sweden and results in substantial weight loss. Approximately one year post-surgery weight regain for these patient are common, followed by a decrease in health related quality of life (HRQoL) and physical activity (PA). Our aim is to investigate the effects of a dissonance-based intervention on HRQoL, PA and other health-related behaviors in female RYGB patients 24 months after surgery. We are not aware of any previous RCT that has investigated the effects of a similar intervention targeting health behaviors after RYGB.

Methods

The ongoing RCT, the “WELL-GBP”-trial (wellbeing after gastric bypass), is a dissonance-based intervention for female RYGB patients conducted at five hospitals in Sweden. The participants are randomized to either control group receiving usual follow-up care, or to receive an intervention consisting of four group sessions three months post-surgery during which a modified version of the Stice dissonance-based intervention model is used. The sessions are held at the hospitals, and topics discussed are PA, eating behavior, social and intimate relationships. All participants are asked to complete questionnaires measuring HRQoL and other health-related behaviors and wear an accelerometer for seven days before surgery and at six months, one year and two years after surgery. The intention to treat and per protocol analysis will focus on differences between the intervention and control group from pre-surgery assessments to follow-up assessments at 24 months after RYGB. Patients’ baseline characteristics are presented in this protocol paper.

Discussion

A total of 259 RYGB female patients has been enrolled in the “WELL-GBP”-trial, of which 156 women have been randomized to receive the intervention and 103 women to control group. The trial is conducted within a Swedish health care setting where female RYGB patients from diverse geographical areas are represented. Our results may, therefore, be representative for female RYGB patients in the country as a whole. If the intervention is effective, implementation within the Swedish health care system is possible within the near future.

Trial registration

The trial was registered on February 23th 2015 with registration number ISRCTN16417174.

Resting Metabolic Rate, Total Daily Energy Expenditure, and Metabolic Adaptation 6 Months and 24 Months After Bariatric Surgery

OBJECTIVE

Little is known about long-term metabolic (energy expenditure) adaptation after bariatric surgery.

METHODS

Resting metabolic rate under basal conditions (RMR), total daily energy expenditure (TDEE), and body composition were measured in 25 participants in the Longitudinal Assessment of Bariatric Surgery-2.

RESULTS

Six months after surgery, BMI (±SD) decreased (47 ± 6 kg/m² to 37 ± 5 kg/m² ), body fat went from 48% ± 6% to 40% ± 6% fat, and fat-free mass went from 67 ± 9 kg to 60 ± 9 kg. In absolute terms, RMR and TDEE both decreased significantly (1,730 ± 278 kcal/d vs. 1,430 ± 200 kcal/d and 2,879 ± 544 kcal/d vs. 2,369 ± 304 kcal/d), and the achieved energy balance was -1,293 ± 355 kcal/d. Sixteen of these participants underwent repeated measures at ∼24 months; TDEE decreased 6 months postoperatively (2,957 ± 540 kcal/d to 2,423 ± 324 kcal/d; P = 0.0003), but at ∼24 months, TDEE (2,602 ± 471 kcal/d) was not significantly different compared with month 6. The average negative energy balance from baseline to month 24 was -379 ± 131 kcal/d.

CONCLUSIONS

RMR and TDEE fall precipitously in the first 6 months after bariatric surgery, but these adaptive changes were no longer significant after 2 years.

Supervised Physical Training Improves Weight Loss After Roux-en-Y Gastric Bypass Surgery: A Randomized Controlled Trial

OBJECTIVE

Bariatric surgery results in significant weight loss and reduces cardiovascular morbidity. However, a large variation in postsurgery weight loss is seen. Physical activity promotes weight loss in nonsurgically treated subjects with obesity. The aim of this study was to investigate the effects of 6 months of supervised physical training following Roux-en-Y gastric bypass surgery (RYGB) on body weight and cardiovascular risk markers.

METHODS

Sixty participants eligible for RYGB were included. Six months post surgery, the participants were randomly assigned to either twice-weekly supervised physical training sessions in a fitness center (INT) or a control group (CON) for 26 weeks. Before surgery and 6, 12, and 24 months after surgery, the participants underwent an examination program that included anthropometric measurements, blood pressure, heart rate, blood samples, and an abdominal computed tomography scan.

RESULTS

RYGB significantly reduced body weight and improved cardiovascular risk markers (all P < 0.01). The supervised physical training intervention resulted in a 4.2-kg (CI: -0.2 to -8.3 kg) lower body weight in INT compared with CON at the study end (P = 0.042). The high-density lipoprotein concentration was significantly higher in INT than in CON at the termination of the intervention, but this was not maintained at the 24-months examination.

CONCLUSIONS

Physical training following RYGB improves weight loss and cardiovascular health.

Bariatric Surgery Resistance: Using Preoperative Lifestyle Medicine and/or Pharmacology for Metabolic Responsiveness

Bariatric surgery is an effective and durable treatment for individuals with obesity and its associated comorbidities. However, not all patients meet weight loss and/or cardiometabolic goals following bariatric surgery, suggesting that some people are bariatric surgery resistant. The reason for this resistance is unclear, but potential factors, such as adiposity-derived inflammation, insulin resistance, hyperglycemia, and aerobic fitness prior to surgery, have been related to blunted surgery responsiveness. Exercise, diet, and/or pharmacology are effective at reducing inflammation and improving insulin action as well as physical function. Herein, we present data that supports the novel hypothesis that intervening prior to surgery can enhance disease resolution in people who are resistant to bariatric surgery.

Effects of gastric bypass surgery followed by supervised physical training on inflammation and endothelial function: A randomized controlled trial

BACKGROUND AND AIMS

Obesity and physical inactivity are both associated with low-grade inflammation and endothelial dysfunction. Bariatric surgery improves markers of inflammation and endothelial function, but it is unknown if physical training after bariatric surgery can improve these markers even further. Therefore, we aimed to investigate the effects of Roux-en-Y gastric bypass (RYGB) followed by physical training on markers of low-grade inflammation and endothelial function.

METHODS

Sixty patients approved for RYGB underwent examinations pre-surgery, 6, 12, and 24 months post-surgery. Six months post-surgery, they were randomized 1:1 to an intervention group or a control group. The interventions consisted of two weekly sessions of supervised moderate intensity physical training for a period of 26 weeks. Fasting blood samples were analyzed for concentrations of interleukin 6 (IL-6), C-reactive protein (CRP), intercellular adhesion molecule 1 (ICAM-1), tissue-type plasminogen activator antigen (t-PA:Ag) and von Willebrand factor (vWF).

RESULTS

RYGB markedly improved markers of inflammation (IL-6, CRP) (p < 0.001) and endothelial function (ICAM-1, t-PA:Ag, vWF) (p < 0.05), and the improvements were sustained 24 months post-surgery (p < 0.01), except for the effects on vWF. We found no correlations between the changes in weight or BMI and the changes in markers of inflammation and endothelial function, except that the change in vWF was found to be inversely correlated with the changes in weight and BMI. We observed no effects of supervised physical training on markers on inflammation or endothelial function (p>0.1 for all).

CONCLUSIONS

RYGB causes substantial and sustained favorable effects on markers of inflammation and endothelial function. Supervised physical training after RYGB did not cause additional improvements.

Brain Feeding Circuits after Roux-en-Y Gastric Bypass

Metabolic surgical procedures, such as Roux-en-Y gastric bypass (RYGB), uniquely reprogram feeding behavior and body weight in obese subjects. Clinical neuroimaging and animal studies are only now beginning to shed light on some of the underlying central mechanisms. We present here the roles of key brain neurotransmitter/neuromodulator systems in food choice, value, and intake at various stages after RYGB. In doing so, we elaborate on how known signals emanating from the reorganized gut, including peptide hormones and microbiota products, impinge on newly mapped homeostatic and hedonic brain feeding circuits. Continued progress in the rapidly evolving field of metabolic surgery will inform the design of more effective weight-loss compounds.

Predictors of Physical Activity After Gastric Bypass-a Prospective Study

BACKGROUND

Most patients do not meet the recommended level of physical activity after bariatric surgery, and psychological factors underlying postoperative physical activity remain poorly understood. This study aimed at identifying self-regulatory predictors of physical activity after bariatric surgery.

METHODS

Questionnaire data including self-regulation variables and the short-version of the International Physical Activity Questionnaire were obtained in a prospective cohort of 230 patients 1 year after Roux-en-Y gastric bypass. The study sample consisted of participants consenting to wear an ActiGraph GT3X+ accelerometer for seven consecutive days, 18-24 months after surgery (n = 120).

RESULTS

A total of 112 participants with complete self-report data provided valid accelerometer data. Mean age was 46.8 years (SD = 9.3), and 81.3% was women. Preoperative and postoperative BMI was 44.8 ± 5.5 and 30.6 ± 5.0 kg/m², respectively. Total weight loss was 28.9% (SD = 7.5). By objective measures, 17.9% of the participants met the recommended level of moderate-to-vigorous-intensity of physical activity of ≥150 min/week, whereas 80.2% met the recommended level according to self-reported measures. Being single, higher education level, and greater self-regulation predicted objective physical activity in multivariate regression analysis. Greater self-regulation also predicted self-reported physical activity. Weight loss 1 year after surgery was not associated with self-reported or objectively measured physical activity.

CONCLUSIONS

Despite large differences between accelerometer-based and subjective estimates of physical activity, the associations of self-regulatory factors and weight loss with postoperative physical activity did not vary depending on mode of measurement. Self-regulation predicted both objective and self-reported physical activity. Targeting patients' self-regulatory ability may enhance physical activity after gastric bypass.

Physical Activity, Decision-Making Abilities, and Eating Disturbances in Pre- and Postbariatric Surgery Patients

BACKGROUND

Physical activity (PA) is considered to have a beneficial influence on executive functioning, including decision-making. Enhanced decision-making after bariatric surgery may strengthen patients' ability to delay gratification, helping to establish appropriate eating behavior. The objectives of this study were to (1) compare a preoperative group with a postoperative group with regard to daily PA, decision-making, and eating disturbances; and (2) investigate the relationship between these variables.

METHODS

The study included 71 bariatric surgery candidates (78 % women, BMI [kg/m²] M = 46.9, SD = 6.0) and 73 postoperative patients (78 % women, BMI M = 32.0, SD = 4.1; 89 % Roux-en-Y gastric bypass, 11 % sleeve gastrectomy; months postoperative M = 8.2, SD = 3.5; total weight loss [%] M = 33.2, SD = 8.9) who completed SenseWear Pro₂ activity monitoring. Decision-making was assessed using a computerized version of the Iowa Gambling Task and eating disorder psychopathology using the Eating Disorder Examination-Questionnaire.

RESULTS

The number of patients who were classified as physically inactive was similarly high in the pre- and postoperative groups. No group differences emerged with regard to decision-making, but the postoperative group exhibited less eating disturbances than the preoperative group. No significant associations were found between PA, decision-making, and eating behavior.

CONCLUSIONS

Patients after bariatric surgery were not more physically active than bariatric surgery candidates, which should be considered in care programs. Additionally, future research is needed to explore the possible link between PA, patients' decision-making abilities, and eating disturbances concerning dose-response questions.

Basal Ganglia Dysfunction Contributes to Physical Inactivity in Obesity

Obesity is associated with physical inactivity, which exacerbates the health consequences of weight gain. However, the mechanisms that mediate this association are unknown. We hypothesized that deficits in dopamine signaling contribute to physical inactivity in obesity. To investigate this, we quantified multiple aspects of dopamine signaling in lean and obese mice. We found that D2-type receptor (D2R) binding in the striatum, but not D1-type receptor binding or dopamine levels, was reduced in obese mice. Genetically removing D2Rs from striatal medium spiny neurons was sufficient to reduce motor activity in lean mice, whereas restoring G_i signaling in these neurons increased activity in obese mice. Surprisingly, although mice with low D2Rs were less active, they were not more vulnerable to diet-induced weight gain than control mice. We conclude that deficits in striatal D2R signaling contribute to physical inactivity in obesity, but inactivity is more a consequence than a cause of obesity.

Running from Disease: Molecular Mechanisms Associating Dopamine and Leptin Signaling in the Brain with Physical Inactivity, Obesity, and Type 2 Diabetes

Physical inactivity is a primary contributor to diseases such as obesity, cardiovascular disease, and type 2 diabetes. Accelerometry data suggest that a majority of US adults fail to perform substantial levels of physical activity needed to improve health. Thus, understanding the molecular factors that stimulate physical activity, and physical inactivity, is imperative for the development of strategies to reduce sedentary behavior and in turn prevent chronic disease. Despite many of the well-known health benefits of physical activity being described, little is known about genetic and biological factors that may influence this complex behavior. The mesolimbic dopamine system regulates motivating and rewarding behavior as well as motor movement. Here, we present data supporting the hypothesis that obesity may mechanistically lower voluntary physical activity levels via dopamine dysregulation. In doing so, we review data that suggest mesolimbic dopamine activity is a strong contributor to voluntary physical activity behavior. We also summarize findings suggesting that obesity leads to central dopaminergic dysfunction, which in turn contributes to reductions in physical activity that often accompany obesity. Additionally, we highlight examples in which central leptin activity influences physical activity levels in a dopamine-dependent manner. Future elucidation of these mechanisms will help support strategies to increase physical activity levels in obese patients and prevent diseases caused by physical inactivity.

Do Dopaminergic Impairments Underlie Physical Inactivity in People with Obesity?

Obesity is associated with physical inactivity, which exacerbates the negative health consequences of obesity. Despite a wide consensus that people with obesity should exercise more, there are few effective methods for increasing physical activity in people with obesity. This lack is reflected in our limited understanding of the cellular and molecular causes of physical inactivity in obesity. We hypothesize that impairments in dopamine signaling contribute to physical inactivity in people with obesity, as in classic movement disorders such as Parkinson's disease. Here, we review two lines of evidence supporting this hypothesis: (1) chronic exposure to obesogenic diets has been linked to impairments in dopamine synthesis, release, and receptor function, particularly in the striatum, and (2) striatal dopamine is necessary for the proper control of movement. Identifying the biological determinants of physical inactivity may lead to more effective strategies for increasing physical activity in people with obesity, as well as improve our understanding of why it is difficult for people with obesity to alter their levels of physical activity.

Changes in physical activity after bariatric surgery: using objective and self-reported measures

BACKGROUND

Many studies using self-reported physical activity (PA) assessment tools have suggested there is an increase in PA after bariatric surgery.

OBJECTIVES

Our aim was to assess PA and sedentary behavior before bariatric surgery and at 6 months after, using subjective and objective tools.

SETTING

Bariatric surgery candidates were recruited from a single center.

METHODS

Demographic data, medical history, current medications, and anthropometric measurements were recorded. Participants were asked to complete a PA and lifestyle questionnaire and to wear an accelerometer on their nondominant wrist. Data were collected before and at 6 months after surgery.

RESULTS

Twenty-two participants were included (17 gastric bypass; 4 sleeve gastrectomy; 1 intragastric balloon). Mean age was 46 years and the majority were female (72%). At a median of 6.3 months follow-up, there were significant reductions in measures of body fatness with a mean reduction of 27 kg in weight. The majority of daytime (12.5±1.1 out of 16 h) was spent in sedentary behavior presurgery with little change postsurgery (12.2±1.2; P = .186). Objectively measured mean moderate-vigorous PA did not change significantly from pre- to postsurgery (mean 11.5±13.9 and 11.6±13.1 min/d, respectively; P = .971). Self-reported total nonoccupational PA did not change significantly (P = .390).

CONCLUSIONS

The majority of bariatric surgery candidates were physically inactive presurgery, and there was no significant change in either subjectively or objectively measured PA at follow-up. This patient group may benefit from objective PA assessment and interventions aimed at increasing PA.

Relationship among physical activity, sedentary behaviors, and cardiometabolic risk factors during gastric bypass surgery-induced weight loss

BACKGROUND

The impact of daily physical activity (PA) on the cardiometabolic risk of bariatric surgery patients is not known.

OBJECTIVE

We examined the influence of physical activity and sedentary behavior on modifying cardiometabolic risk after Roux-en-Y gastric bypass (RYGB) surgery.

SETTING

University of Pittsburgh Medical Center and East Carolina University bariatric surgery centers.

METHODS

Data from 43 women and 7 men who completed testing at 1-3 months after RYGB surgery and again at 9 months postsurgery were analyzed. Outcomes measured included PA level (min/d), steps/d, sedentary time, and body composition. Insulin sensitivity was determined with an intravenous glucose tolerance test. Weight and blood lipid profiles also were obtained.

RESULTS

Patients reduced body mass index by a mean of -8.0±3.4 kg/m² (P<.001), increased moderate-to-vigorous PA by 17.0±47.0 min/d (P = .014), and decreased sedentary time (-47.9±101.0 min/d, P = .002). However, 24% of patients decreased overall PA (P<.001), and 39% increased sedentary behavior (P<.001). Changes in overall PA (rho = -.33, P = .006) and steps/d (rho = -.31, P = .0106) were related to weight loss. Insulin sensitivity was associated with light PA before (rho = .37, P<.001) and after (rho = .37, P = .015) intervention. Increasing overall PA also was related to higher levels of high-density lipoprotein cholesterol (rho = .33, P<.01). Decreasing sedentary time was related to decreased fat mass (rho = .35, P = .012) but not to other cardiometabolic risk factors.

CONCLUSIONS

The majority of patients increased PA (76%) and decreased sedentary time (61%) after RYGB surgery, but the amount of PA and sedentary time varied substantially. Higher PA, even at low intensity levels, was related to beneficial outcomes in body composition, insulin sensitivity, and high-density lipoprotein cholesterol.

Changes in physical activity behaviour and physical function after bariatric surgery: a systematic review and meta-analysis

Although physical activity performed after bariatric surgery is associated with enhanced weight loss outcomes, there is limited information on patients' physical activity behaviour in this context. This systematic review and meta-analysis assessed pre-operative to post-operative changes in physical activity and physical function outcomes among obese adults undergoing bariatric surgery. A total of 50 studies met inclusion criteria with 26 papers reporting data for meta-analysis. Increases in both objectively recorded and self-reported physical activity at 12 months were demonstrated. Studies indicated that there was a shift towards a greater amount of active time, but of a lower intensity within the first 6 months of bariatric surgery, suggested by a reduction in moderate to vigorous physical activity but an increase in step count. A standardized mean difference (SMD) of 1.53 (95% CI: 1.02-2.04) based on nine studies indicated improved walking performance at 12 months. Similarly, analysis of five studies demonstrated increased musculoskeletal function at 3-6 months (SMD: 1.51; 95% CI: 0.60-2.42). No relationship was identified between changes in weight and walking performance post-surgery. More studies assessing physical activity, physical function and weight loss would help understand the role of physical activity in optimizing post-operative weight and functional outcomes.

Measurement and Intervention on Physical Activity and Sedentary Behaviours in Bariatric Surgery Patients: Emphasis on Mobile Technology

Physical activity (PA) and sedentary behaviours (SB-i.e. activities involving low-energy expenditure and a sitting/reclining posture) may each have significant implications for weight loss and other bariatric surgery outcomes. While early studies suggested that patients typically comply with clinical recommendations to adopt habitual PA, these data were based on retrospective questionnaires. Conversely, recent studies incorporating mobile health (mHealth) technologies (e.g. objective monitors), which assess PA and SB in real time and in the natural environment, show that most patients are inactive and highly sedentary pre-operatively and only make modest changes in these behaviours postoperatively. In addition to using mHealth technologies for obtaining accurate and detailed information on PA and SB, they are increasingly being employed to intervene on patients' PA and SB and/or evaluate intervention outcomes. Researchers and clinicians are encouraged to consider the benefits of using mHealth technology when studying and treating PA and SB in bariatric surgery patients.

Physical activity is unrelated to cognitive performance in pre-bariatric surgery patients

OBJECTIVE

To investigate the relationship between physical activity (PA) and cognitive performance in extreme obesity.

METHODS

Seventy-one bariatric surgery candidates (77.5% women) with a mean body mass index (BMI) of 46.9 kg/m2 (SD=6.0) and a mean age of 41.4 (SD=11.9) years completed SenseWear Pro2 activity monitoring for seven days. Cognitive functioning was assessed by a computerized test battery including tasks of executive function (Iowa Gambling Task), visuospatial short-term memory (Corsi Block Tapping Test) and verbal short-term memory (Auditory-Verbal Learning Test). Questionnaires assessing eating disturbances and depressive symptoms were administered. Somatic comorbidities were assessed by medical chart review.

RESULTS

The level of PA was low with mean steps per day within wear time being 7140 (SD=3422). Most patients were categorized as sedentary (31.0%) or low active (26.8%). No significant association between PA estimates and cognitive performance was found. Lower PA was modestly correlated with higher BMI but not with age, somatic comorbidity or depressive symptoms. Moderated regression analyses suggested a significant interaction effect between depression and PA in predicting performance on the Corsi Block Tapping Test. Patients with (29.6%) and without (70.4%) regular binge eating did not differ with respect to PA or cognitive function.

CONCLUSION

The findings indicate no association between daily PA and cognitive performance in morbidly obese patients. Future studies should explore the relationship between the variables with regard to dose-response-questions, a broader BMI range and with respect to potential changes after substantial weight loss due to bariatric surgery.

Objective assessment of changes in physical activity and sedentary behavior: Pre- through 3 years post-bariatric surgery

OBJECTIVE

To evaluate change in sedentary behavior (SB) and physical activity (PA) over 3 years following bariatric surgery.

METHODS

A subset of participants in an observational study (n = 473 of 2,458; 79% female, median body mass index 45 kg m(-2) ) wore an activity monitor presurgery and at 1-3 annual postsurgery assessments.

RESULTS

Over the first year, on average, sedentary time decreased from 573 (95% CI: 563-582) to 545 (95% CI: 534-555) min days(-1) and moderate- to vigorous-intensity PA (MVPA) increased from 77 (95% CI: 71-84) to 106 (95% CI: 98-116) min week(-1) , or 7 (95% CI: 5-10) to 24 (95% CI: 18-29) min week(-1) in MVPA bouts ≥10 min. There were no changes in these parameters from years 1 to 3 (P for all > 0.05). The percentage of participants achieving ≥150 min week(-1) of bout-related MVPA was not different at year 3 [6.5% (95% CI: 3.1-12.7)] vs. presurgery [3.4% (95% CI: 1.8-5.0); P = 0.45]. Most participants followed SB and PA trajectories that paralleled mean change and were consistent with their presurgery position in relation to the group.

CONCLUSIONS

On average, bariatric surgical patients make small reductions in SB and increases in PA during the first postsurgery year, which are maintained through 3 years. Still, postsurgery PA levels fall short of PA guidelines for general health or weight control.