Associations Between Changes in Activity and Dietary Behaviors after Metabolic and Bariatric Surgery

Impact of Laparoscopic Sleeve Gastrectomy on Fatigue in Obese Patients

Background: Fatigue with obesity negatively affects the motivation to lose weight and causes failure of treatment. So, obesity and fatigue are two related entities that worsen each other in a vicious circle. This study aimed to examine the changes in fatigue levels in obese patients undergoing laparoscopic sleeve gastrectomy (LSG). Methods: Preoperative and postoperative BMI, fat percentage, and obesity degree were determined based on Tanita test results, and the rates of change were calculated. The Fatigue Assessment Scale (FAS) was used to assess the impact of obesity on mental and physical fatigue. Results: Six months after LSG, there was a 29.7% decrease in Body Mass Index (BMI) across all patients (45.0 to 31.4, p < 0.001). Significant reductions in the percentage of body fat, obesity grade, and HgA1C were observed in both women and men and overall (p < 0.001 for all comparisons). Scores on the Fatigue Assessment Scale (FAS) for total, mental, and physical scales decreased significantly for women, men, and all participants (p < 0.001 for all comparisons). There was a weak but significant positive correlation between the percentage change in FAS total and FAS physical scale scores and the change in BMI% (p = 0.015 and 0.004; r = 0.089, 0.106, respectively). Change in obesity grade and FAS physical subscale scores negatively correlated (p = 0.029, r = 0.080). Conclusions: LSG not only leads to significant weight reduction but also improves fatigue levels in patients with obesity.

Associations of adherence to physical activity and dietary recommendations with weight recurrence 1-5 years after metabolic and bariatric surgery

BACKGROUND

Little is known about longer-term adherence to recommended physical activity (PA) and dietary behaviors after metabolic and bariatric surgery (MBS) and whether adherence is associated with weight recurrence.

OBJECTIVES

To explore (1) changes in and associations between adherence to PA and general dietary recommendations after MBS and (2) whether PA and dietary behaviors interact to predict weight recurrence.

SETTING

University hospital; public practice.

METHODS

Participants completed ActiGraph PA monitoring, dietary questionnaire, and weighing 1 and 5 years after surgery. Parametric and non-parametric tests evaluated changes in and associations between adherence to PA and dietary recommendations. Multiple linear regression explored associations of adherence and weight recurrence 5 years post-surgery.

RESULTS

A total of 73 participants (66% loss to follow-up, 80.8% females) were included. From 1 to 5 years after surgery, adherence to PA recommendations did not change (23.5% versus 20.5%, P = .824), whereas adherence to dietary recommendations decreased (P = <.001). Adherence to PA recommendations is positively associated with eating fruits and vegetables and limiting intake of sugar and fat at 1 year (P < .05) and negatively associated with choosing meat with less fat at 5 years (P = .018). Adherence to PA and dietary behaviors did not independently contribute or interact to predict weight recurrence.

CONCLUSIONS

Adherence to recommendations was poor. Dietary adherence decreased from 1 to 5 years post-surgery, whereas PA adherence remained stable. PA adherence was positively associated with adherence to some dietary recommendations at 1 year but not at 5 years. Neither behavioral adherences were associated with weight recurrence. Additional research is needed to understand how to improve adherence and its relationship with other health outcomes after MBS.

Transcranial Magnetic Stimulation for Reducing the Relative Reinforcing Value of Food in Adult Patients With Obesity Pursuing Metabolic and Bariatric Surgery: Protocol for a Pilot, Within-Participants, Sham-Controlled Trial

BACKGROUND

Metabolic and bariatric surgery (MBS) is the most effective and durable obesity treatment. However, there is heterogeneity in weight outcomes, which is partially attributed to variability in appetite and eating regulation. Patients with a strong desire to eat in response to the reward of palatable foods are more likely to overeat and experience suboptimal outcomes. This subgroup, classified as at risk, may benefit from repetitive transcranial magnetic stimulation (rTMS), a noninvasive brain stimulation technique that shows promise for reducing cravings and consumption of addictive drugs and food; no study has evaluated how rTMS affects the reinforcing value of food and brain reward processing in the context of MBS.

OBJECTIVE

The goal of the Transcranial Magnetic Stimulation to Reduce the Relative Reinforcing Value of Food (RESTRAIN) study is to perform an initial rTMS test on the relative reinforcing value (RRV) of food (the reinforcing value of palatable food compared with money) among adult patients who are pursuing MBS and report high food reinforcement. Using a within-participants sham-controlled crossover design, we will compare the active and sham rTMS conditions on pre- to posttest changes in the RRV of food (primary objective) and the neural modulation of reward, measured via electroencephalography (EEG; secondary objective). We hypothesize that participants will show larger decreases in food reinforcement and increases in brain reward processing after active versus sham rTMS.

METHODS

Participants (n=10) will attend 2 study sessions separated by a washout period. They will be randomized to active rTMS on 1 day and sham rTMS on the other day using a counterbalanced schedule. For both sessions, participants will arrive fasted in the morning and consume a standardized breakfast before being assessed on the RRV of food and reward tasks via EEG before and after rTMS of the left dorsolateral prefrontal cortex.

RESULTS

Recruitment and data collection began in December 2022. As of October 2023, overall, 52 patients have been screened; 36 (69%) screened eligible, and 17 (47%) were enrolled. Of these 17 patients, 3 (18%) were excluded before rTMS, 5 (29%) withdrew, 4 (24%) are in the process of completing the protocol, and 5 (29%) completed the protocol.

CONCLUSIONS

The RESTRAIN study is the first to test whether rTMS can target neural reward circuits to reduce behavioral (RRV) and neural (EEG) measures of food reward in patients who are pursuing MBS. If successful, the results would provide a rationale for a fully powered trial to examine whether rTMS-related changes in food reinforcement translate into healthier eating patterns and improved MBS outcomes. If the results do not support our hypotheses, we will continue this line of research to evaluate whether additional rTMS sessions and pulses as well as different stimulation locations produce clinically meaningful changes in food reinforcement.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05522803; https://clinicaltrials.gov/study/NCT05522803.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/50714.