Establishment of Adequate Nutrient Intake Criteria to Achieve Target Weight Loss in Patients Undergoing Bariatric Surgery

Intestinal energy harvest is associated with post-bariatric surgery weight loss

Background/Objectives

Metabolic and bariatric surgery (MBS) is the most effective treatment for severe obesity; however, a significant subset of patients does not achieve expected weight loss or have substantial weight recurrence over time. The intestinal energy harvest is a potential determinant of varying weight loss outcomes, but with limited exploration. We assess the relationships between diet, intestinal energy harvest, and weight outcomes over 24 months in individuals who have undergone MBS.

Subjects/Methods

Calorie absorption was assessed with bomb calorimetry and dietary questionnaires before and after MBS. Within a total of 67 patients, fecal energy density was measured in 67, 56, 60, 67, 44, 47 samples at 0, 1, 6, 12, 18, and 24 months, respectively. Multivariate regression was developed to identify potential weight loss predictors, and random forest algorithms were employed to forecast weight results based on intestinal energy harvest.

Results

Intestinal energy harvest enhanced the predictability of patient weight loss outcomes with random forest models. A notable difference in relative fecal energy content was observed between patients experiencing optimal and sub-optimal weight loss (p<0.01). Prior to MBS, an increased energy content in feces (indicating less energy absorption) is associated with greater weight loss after the operation. Associations between diet and energy harvest were insignificant.

Conclusion

MBS changes energy harvest capacity post-surgery. A higher relative fecal energy content (lower energy absorption) at one month correlates with better weight loss outcomes at 6M, 12M, 18M and 24M post-MBS. Findings may guide the development of diagnostic tools and treatment guidelines for patients at risk of suboptimal weight loss outcomes.

CLINICAL TRIAL REGISTRATION

The trial is registered at clinicaltrials.gov (NCT03065426).

Enhancing Clinical Success Through Intensive Dietary Support in Bariatric Patients: a Retrospective Study in Asian Population

BACKGROUND

Weight loss surgery is an established intervention for obesity and related conditions, ensuring sustained weight reduction and improved comorbidities. Post-bariatric surgery, maintaining nutritional adequacy and weight loss necessitates ongoing, intensive dietary support. This research aims to discern the impact of standard care vs. intensive dietary support on outcomes following bariatric surgery within an Asian demographic. This study aims to research the part that intensive dietary support plays in contrast to standard care in altering weight loss and BMI change following bariatric surgery.

METHODS

A retrospective analysis of medical records from a Malaysian tertiary care hospital documented bariatric surgeries conducted from January 2020 to January 2022. Rigorous criteria selected 200 patients from 327, evenly split between standard care and intensive dietary support groups. The latter underwent six mandatory visits with a surgeon and a dietitian in the initial 3 months post-surgery. A dual-review mechanism was implemented for data interpretation, increasing robustness, and reducing biases in our findings.

RESULTS

At 6 and 12 months, the intensive dietary support group exhibited significantly greater weight loss and BMI reduction (p < 0.01). Postoperative complications did not significantly differ between groups.

CONCLUSION

In an Asian population, intensive dietary support enhances weight loss and BMI reduction compared to standard care after bariatric surgery.

Nutrition, Physical Activity, and Prescription of Supplements in Pre- and Post-bariatric Surgery Patients: An Updated Comprehensive Practical Guideline

Only in the USA, 315 billion dollars are spent annually on the medical cost of obesity in adult patients. Till now, bariatric surgery is the most effective method for treating obesity and can play an essential role in reducing the direct and indirect costs of obesity treatment. Nonetheless, there are few comprehensive guidelines which include nutrition, physical activity, and supplements, before and after surgery. The purpose of the present narrative review is to provide an updated and comprehensive practical guideline to help multidisciplinary teams. The core keywords include nutrition, diet, physical activity, exercise, supplements, macronutrients, micronutrients, weight reduction, bariatric surgery, Roux-en-Y Gastric Bypass, Sleeve Gastrostomy, Laparoscopic Adjustable Gastric Banding, and Biliopancreatic diversion with duodenal switch which were searched in databases including PubMed/Medline, Cochrane, and some other sources such as Google Scholar. We answered questions in five important areas: (a) nutritional strategies before bariatric surgery, (b) nutrition after bariatric surgery, (c) physical activity before and after bariatric surgery, (d) weight regain after bariatric surgery, and (e) micronutrient assessments and recommendations before and after bariatric surgery. Some new items were added in this updated guideline including "weight regain" and "pregnancy after bariatric surgery." Other fields were updated based on new evidence and guidelines.

Longer-Term Weight Loss Outcomes Are Not Primarily Driven by Diet Following Roux-en-Y Gastric Bypass and Sleeve Gastrectomy

Metabolic and bariatric surgery (MBS) is the most effective long-term treatment for Class III obesity. Reduced dietary intake is considered a behavioral driver of post-surgical weight loss, but limited data have examined this association. Therefore, this study examined prospective, longitudinal relationships between dietary intake and weight loss over 24 months following Roux-en-Y Gastric Bypass and Sleeve Gastrectomy. Relationships between weight loss and dietary intake were examined using a validated 24-h dietary recall method. Associations between total energy/macronutrient intake and weight loss outcomes were assessed at 12-, 18-, and 24-months following MBS, defining patients as "responders" and "suboptimal responders". Consistent with previous literature, 12-month responders and suboptimal responders showed significant associations between weight loss and energy (p = 0.018), protein (p = 0.002), and total fat intake (p = 0.005). However, this study also revealed that many of these associations are no longer significant 24 months post-MBS (p > 0.05), despite consistent weight loss trends. This study suggests a short-term signal between these dietary factors and weight loss outcomes 12 months post-MBS; however, this signal does not persist beyond 12 months. These results are essential for interpreting and designing clinical studies measuring long-term post-surgical weight loss outcomes.

Relationship between dietary macronutrient composition with weight loss after bariatric surgery: A systematic review

This systematic review evaluated the relationship between macronutrient intake and weight loss after bariatric surgery (BS). The MEDLINE/Pubmed, EMBASE, COCHRANE/CENTRAL, and SCOPUS databases were accessed in August 2021 to search for eligible articles: original publications with adults undergoing BS and indicating the relationship between macronutrients and weight loss. Titles that did not meet these criteria were excluded. The review was written according to the PRISMA guide, and the risk of bias was according to the Joanna Briggs manual. Data were extracted by one reviewer and checked by another. Eight articles with 2.378 subjects were included. The studies indicated a positive relationship between weight loss and protein intake after BS. Prioritization of protein followed by carbohydrates with a lower percentage of lipids favors weight loss and increases weight stability after BS. Among the results found, a 1% increase in protein intake raises the probability of obesity remission by 6%, and high-protein diet increase 50% weight loss success. Limitations are the methods of included studies and review process. It is concluded that high-protein intake >60 g a 90 g/day may favor weight loss and maintenance after BS, but it is relevant to balance the other macronutrients.

Postoperative Resting Metabolic Rate and Successful Weight Loss After Roux-en-Y Gastric Bypass

OBJECTIVE

To analyze whether changes in RMR 6 months after RYGB could be a predictor of weight loss on late follow-up.

METHODS

Prospective study of 45 individuals submitted to RYGB in a university tertiary care hospital. Body composition was evaluated by bioelectrical impedance analysis and RMR by indirect calorimetry before (T0), 6 (T1), and 36 months (T2) after surgery.

RESULTS

RMR/day was lower in T1 (1.552 ± 275 kcal/day) than in T0 (1734 ± 372 kcal/day; p < 0.001) with a return to similar values at T2 (1.795 ± 396 kcal/day; p < 0.001). In T0, there was no correlation between RMR/kg and body composition. In T1, there was a negative correlation between RMR and BW, BMI, and % FM, and a positive correlation with % FFM. The results in T2 were similar to T1. There was a significant increase in RMR/kg between T0, T1, and T2 (13.6 ± 2.2 kcal/kg, 16.9 ± 2.7 kcal/kg, and 19.9 ± 3.4 kcal/kg) in the total group and according to gender. Eighty percent of the patients who had increased RMR/kg ≥ 2 kcal at T1 achieved > 50% EWL in T2, particularly in women (odds ratio: 27.09, p < 0.037).

CONCLUSIONS

The increase in RMR/kg after RYGB is a major factor related to a satisfactory % excess weight loss on late follow-up.

Assessment of the Clinical Condition and Way of Patients' Nutrition before and after Laparoscopic Sleeve Gastrectomy

One of the most commonly performed bariatric procedures is the laparoscopic sleeve gastrectomy (LSG). It is highly effective in reducing body weight, but it carries the risk of developing nutritional deficiencies and their consequences. The aim of the study was to determine the clinical condition of obese patients after LSG in terms of nutritional status, metabolic disorders, and way of nutrition. Thirty participants (15 women and 15 men) took part in the study. A statistically significant reduction in the total body fat mass (women by 37.5% p < 0.05, men by 37.06% p < 0.05) and total fat free mass (women by 10% p < 0,05, men by 12.5% p < 0.05) was demonstrated 6 months after LSG. Moreover, insufficient protein intake has been shown in over 73% of women and 40% of men. Before and 6 months after LSG, insufficient intake of calcium, magnesium, potassium, folate, vitamin D, and iron was observed. Six months after the LSG, significant decreases of fasting glucose (p < 0.05), insulin (p < 0.05), TG (p < 0.05), and AST (p < 0.05) concentrations, were observed in both groups. Optimization of nutrition in order to prevent nutritional deficiencies and their complications is a key element of the therapy of obese patients treated surgically.

Determinants of Dietary Adherence Among Chinese Patients After Bariatric Surgery Based on the Attitude-Social Influence-Efficacy Model

PURPOSE

To explore main determinants of dietary adherence among Chinese patients after bariatric surgery based on the Attitude-Social influence-Efficacy (ASE) model.

METHODS

A cross-sectional survey was conducted by using convenience sampling method to select 288 participants in a tertiary hospital in Jiangsu, China. General information and disease-related information were collected as well as applying the Dietary Adherence Scale after Bariatric Surgery (DASBS) and Attitude-Social influence-Efficacy Questionnaire after Bariatric Surgery (ASEQBS). Univariate analysis, correlation analysis, and multivariate analysis were used to identify determinants of dietary adherence among patients after bariatric surgery.

RESULTS

A total of 288 questionnaires were effectively collected. The mean DASBS score was 54.90 ± 10.08 among post-bariatric patients. Univariate analysis results showed that education level, time since surgery, smoking, exercise, participation in peer support groups, and participation in nutrition counseling had significant effects on postoperative diet adherence level of patients (P < 0.05). The correlation analysis results showed that the total score of dietary adherence was positively correlated with the total score of intention, attitude, social influence, and self-efficacy, and the correlation coefficients were 0.511, 0.550, 0.460, and 0.484, respectively (P < 0.05). The results of multiple linear regression analysis showed that time since surgery, attitude, intention, social influence, exercise, and self-efficacy entered the regression equation (P < 0.05). The standardized regression coefficients of attitude and intention are 0.237 and 0.196, respectively. The regression model could explain 44.0% of the total variation.

CONCLUSION

The dietary adherence of Chinese post-bariatric patients is at an upper-middle level, which needs to be further improved. Time since surgery, exercise, intention, attitude, social influence, and self-efficacy had significant effects on patients' dietary adherence. Attitude had the greatest effect on dietary adherence, followed by intention. The results shed light on that these factors should be emphasized to take personalized intervention strategy in designing dietary intervention program, in order to improve the patient's dietary adherence and surgical outcomes.

Development and Validation of a Questionnaire to Assess the Determinants of Dietary Adherence Among Patients After Bariatric Surgery

PURPOSE

This study was aimed to develop a questionnaire to assess the determinants of dietary adherence among patients after bariatric surgery based on the attitude-social influence-efficacy (ASE) model and to evaluate its psychometric properties.

PATIENTS AND METHODS

According to semi-structured interview, Delphi expert consultation and pilot study, the initial questionnaire was formed and applied to investigate 319 patients after bariatric surgery in a tertiary hospital in Jiangsu Province, China. The reliability and validity of the scale were tested.

RESULTS

The 28-item of the attitude-social influence-efficacy questionnaire after bariatric surgery (ASEQBS) was formed. The results of exploratory factor analysis showed that four factors, including intention, attitude, social influence, and self-efficacy, could be extracted, and the cumulative variance contribution rate reached 59.98%. Confirmatory factor analysis showed the model fit well. The content validity index of each item was 0.800-1.000, and the content validity index of the ASEQBS was 0.857. The total Cronbach's α of the ASEQBS was 0.920, the split-half reliability was 0.774, and the retest reliability was 0.922.

CONCLUSION

The results suggest that ASEQBS is a valid and reliable measure of determinants of dietary adherence. It may be useful to evaluate the influence factors of dietary adherence and helpful to evaluate the efficacy of tailored dietary intervention programs.