Commercial Very Low Energy Meal Replacements for Preoperative Weight Loss in Obese Patients: a Systematic Review

Remote Delivery of Partial Meal Replacement for Weight Loss in People Awaiting Arthroplasty

Background: Obesity is linked to higher rates of complications; lower absolute recovery of mobility, pain, and function; and increased costs of care following total knee or hip arthroplasty (TKA, THA). The aim of this prospective cohort study was to evaluate the effectiveness of a 12-week partial meal replacement (PMR) weight loss program for people awaiting TKA or THA and living with obesity (body mass index (BMI) ≥ 30 kg/m2). Methods: The intervention was delivered remotely and included a 12-week PMR plan of 1200 calories/day, incorporating two meal replacement shakes/soups and a third suitable simple meal option. The intervention support was provided through online group education sessions, one-to-one teleconsultation with a dietitian, and access to a structured PMR App with functions for goal setting and providing educational content on diet, physical activity, and behaviour changes. Results: Of the 182 patients approached, 29 provided consent to participate, 26 participants commenced the program, and 22 participants completed the 12-week PMR plan. Completers exhibited statistically significant weight loss from baseline to 12 weeks, with a paired difference of 6.3 kg (95% CI: 4.8, 7.7; p < 0.001), with 15 out of 22 (68.2%) participants achieving at least 5% weight loss. Statistically significant reductions in HbA1c and low density lipoprotein (LDL) were observed at 12 weeks compared to baseline. Moreover, a significant increase in the proportion of participants in the action and maintenance phases of the readiness to change diet, physical activity, and weight were observed at 12 weeks. The majority of program completers (18 out of 22) expressed willingness to pay for the service if offered on a long-term basis following the arthroplasty. Conclusions: This study's findings demonstrated that significant weight loss is achievable for people living with obesity awaiting arthroplasty following a 12-week PMR weight loss program. The remote delivery of the intervention was feasible and well accepted by people awaiting TKA or THA.

Preoperative dietitian-led Very Low Calorie Diet (VLCD) Clinic for adults living with obesity undergoing gynaecology, laparoscopic cholecystectomy and hernia repair procedures: a pilot parallel randomised controlled trial

Obesity can increase the risk of postoperative complications. Despite increased demand for patients living with obesity to lose weight prior to common surgical procedures, the impact of intentional weight loss on surgical outcomes is largely unknown. We aimed to conduct a pilot study to assess the feasibility of a full-scale randomised controlled trial (RCT) to examine the effect of preoperative dietitian-led Very Low Calorie Diet (VLCD) Clinic on surgical outcomes in gynaecology and general surgeries. Between August 2021 and January 2023, a convenience sample of adults living with obesity (BMI ≥ 30 kg/m2) awaiting gynaecology, laparoscopic cholecystectomy and ventral hernia repair procedures were randomised to dietitian-led VLCD (800-1000 kcal using meal replacements and allowed foods), or control (no dietary intervention), 2-12 weeks preoperatively. Primary outcome was feasibility (recruitment, adherence, safety, attendance, acceptability and quality of life (QoL)). Secondary outcomes were anthropometry and 30-d postoperative outcomes. Outcomes were analysed as intention-to-treat. Fifty-one participants were recruited (n 23 VLCD, n 28 control), mean 48 (sd 13) years, 86 % female, and mean BMI 35·8 (sd 4·6) kg/m2. Recruitment was disrupted by COVID-19, but other thresholds for feasibility were met for VLCD group: high adherence without unfavourable body composition change, high acceptability, improved pre/post QoL (22·1 ± 15 points, < 0·001), with greater reductions in weight (-5·5 kg VLCD v. -0·9 kg control, P < 0·05) waist circumference (-6·6 cm VLCD v. +0·6 control, P < 0·05) and fewer 30-d complications (n 4/21) than controls (n 8/22) (P > 0·05). The RCT study design was deemed feasible in a public hospital setting. The dietitian-led VLCD resulted in significant weight loss and waist circumference reduction compared with a control group, without unfavourable body composition change and improved QoL.

Use of a Very Low Calorie Diet for Weight Loss in a Patient with Acute Kidney Injury and Class III Obesity: A Case Study

Very low calorie diets (VLCDs) induce rapid weight loss through severe energy restriction resulting in ketosis. VLCD manufacturer guidelines list acute kidney injury (AKI) as a contraindication for use with concerns around further damage to kidney function through increased protein catabolic load, diuresis, and risk of electrolyte derangements. We report on the successful concurrent management of AKI alongside provision of a VLCD for weight loss in the acute setting in a patient with class III obesity and comorbid complications during a prolonged hospital stay. AKI resolved at week 5 of a 15-week VLCD program, with no adverse side effects noted on electrolytes, fluid, or kidney function. A weight loss of 76 kg was attained. VLCD appears safe for use in patients with AKI during hospitalization under close medical supervision. Both health system sustainability and patients may benefit from seizing the opportunity to address obesity during protracted hospital admission.

Very low energy diets before nonbariatric surgery: A systematic review and meta-analysis

BACKGROUND

Very low energy diets serve as an intensive approach to weight loss in a short period of time. Although the preoperative use of very low energy diets to optimize patients with obesity before bariatric surgery is well established, the evidence for very low energy diets before other types of surgery remains unclear. The aim of this review was to determine the impact of preoperative very low energy diets on perioperative outcomes in nonbariatric surgery.

METHODS

Medline, EMBASE, CENTRAL, and PubMed were systematically searched from inception through to July 2021. Articles were included if they evaluated very low energy diets use before any type of nonbariatric surgery. The primary outcome was postoperative morbidity. Secondary outcomes included compliance, safety, and preoperative weight loss. A pairwise meta-analyses using inverse variance random effects was performed.

RESULTS

From 792 citations, 13 studies with 395 patients (mean age: 56.5 years, 55.8% female) receiving very low energy diets preoperatively in preparation for nonbariatric surgery were included. Mean duration of preoperative very low energy diets was 6.6 weeks (range, 0.42-17 weeks). Target daily caloric intake ranged from 450 kcal to 1,400 kcal. Compliance with very low energy diets ranged from 94% to 100%. The mean preoperative weight loss ranged from 3.2 kg to 19.2 kg. There were no significant differences in postoperative morbidity (odds ratio, 1.10; 95% confidence interval, 0.64-1.91; P = .72), operative time (standard mean difference -0.35; 95% confidence interval, 1.13-0.43, P = .38), or postoperative length of stay (standard mean difference 0.40, 95% confidence interval -0.11-0.91, P = .12) with very low energy diets.

CONCLUSION

Although the currently available evidence is heterogenous, preoperative very low energy diets are safe, well tolerated, and effectively induce preoperative weight loss in patients undergoing nonbariatric surgery for both benign and malignant disease. Further prospective studies are warranted.

Developing and Piloting a Novel Ranking System to Assess Popular Dietary Patterns and Healthy Eating Principles

A multitude of weight loss diets exist. However, no one diet has been proven to be superior, despite their claims. Resultingly, this creates confusion amongst consumers and conflicting nutrition messages. The aim of the ranking system was to evaluate a range of dietary pattern’s nutrition profile and financial costs, as well as their potential long-term sustainability and associated adverse effects. Nutrition profile is typically the focal point of weight loss diets with less attention focused towards other factors that may affect their suitability. Five popular diets (Keto, Paleo, Intermittent Fasting, Optifast, and 8 Weeks to Wow) and two energy restricted healthy eating principles (Australian Guide to Healthy Eating and the Mediterranean Diet) were compared for diet quality, cost, adverse effects, and support for behaviour change. In general, healthy eating principles scored more favourably compared to popular weight loss diets in all categories. Lower carbohydrate diets tended to score lower for diet quality due to restricting multiple food groups, had more associated adverse effects and did not encourage behaviour change compared to the other weight loss diets. Optifast was the only weight loss diet to receive a negative score for cost. There should be considerations when undertaking a change to dietary patterns beyond nutrition profile. Diets indeed vary in terms of diet quality, and in addition can be costly, incur adverse effects, and disregard behaviour change which is important for sustainable weight loss and maintenance. This ranking system could create a reference point for future comparisons of diets.

The use of very low-calorie diets in subjects with obesity complicated with nonalcoholic fatty liver disease: A scoping review

This scoping review synthesizes the existing research on the use of very low-calorie diets (VLCDs) in subjects with nonalcoholic fatty liver disease (NAFLD) and end-stage liver disease (ESLD). 19 studies were included, of which 5 were clinical trials, 11 were cohort studies, 1 was a case-control study, and 2 were case series totaling 968 subjects. About 17 studies were focused on patients with NAFLD while the two case series described in patients with ESLD on the transplant list or post-liver transplant. Six studies included subjects managed with VLCDs prior bariatric surgery. Most studies were short term and demonstrated acute improvement of diverse liver biomarkers including liver function tests, indices of hepatosteatosis and reduction in liver size. Adherence rates in these studies were between 69% and 93%. Eight studies did not report any adverse events and four subjects were reported to have discontinued VLCD due to adverse effects in two different studies. Aggregated adverse events were mild. Treatments based on VLCD in subjects with NAFLD seem to be safe and tolerable but can result in mild adverse effects. The findings of this scoping review suggest that the use of VLCD in patients with obesity complicated with NAFLD and potentially in ESLD appear to be effective to induce weight loss and to acutely reduce hepatosteatosis.

The relationship between preoperative weight loss and intra and post-bariatric surgery complications: an appraisal of the current preoperative nutritional strategies

Preoperative weight loss before a bariatric surgery reduces long-term complications, but there is no solid evidence for short-term or perioperative complications. This review highlights recent evidence on dietary protocols and the possible correlation between weight loss and surgical complications. Updated evidence was searched in PubMedDirect with the terms "preoperative very low-calorie diet or very-low-calorie ketogenic diet or low-fat diet or intermittent fasting or Mediterranean diet and bariatric surgery or bariatric surgery complications." The main characteristics of each diet, achievements related to weight loss, liver reduction, peri and postoperative outcomes, surgical complications, tolerance, and adherence to the diet are presented from the selected studies. There are few reports about the Mediterranean diet as a strategy to reach these goals. The VLCKD has been associated with better body weight reduction and lesser postoperative complications risk. However, the results in animal models are still controversial. When comparing VLCD with an LCD, there is no apparent superiority between one against the other one. However, LCD has shown better tolerance and adherence than VLCD. There is still a need for more controlled studies to define the best preoperative dietary treatment for weight loss before bariatric surgery since there are controversial positions regarding this issue.

Systematic review of randomized control trials into effective preoperative weight loss interventions and impact on surgical outcomes for major benign gynecological surgery

AIMS

Limited information exists on what preoperative weight loss interventions (lifestyle, pharmacological, surgical) are effective in improving outcomes of elective, nononcological, gynecological surgery. Obesity rates are increasing and associated with poorer operative outcomes. We aimed to identify high quality studies into preoperative weight loss interventions and perform a systematic review of the literature to guide recommendations for reducing gynecological surgical complications and guide future research. Primary outcomes were mortality and surgical complications including conversion to open surgery, duration of surgery, and recovery.

METHODS

The review was pre-registered with PROPSERO. A systematic search was undertaken of the major electronic bibliographic databases. Search results were compiled and abstracts of studies identified before application of the Cochrane highly sensitive search strategy (CHSSS) were reviewed. Full text of studies after application of the CHSSS were evaluated for suitability. For data collection and analysis, a minimum three high-quality randomized control trials were required to synthesize data in relation to the primary outcome.

RESULTS

No trials met the inclusion criteria. No randomized control trials in gynecological cohorts were identified. Studies in gynecology-oncology were excluded due to the confounding nature of weight loss as a feature of illness as opposed to health optimization.

CONCLUSION

There is limited evidence regarding preoperative weight loss interventions in gynecology. Further research is needed as the prevalence of obesity among women is increasing and definitive surgical management options in gynecology remain essential. PROSPERO registration ID: 165643.

Weight loss interventions and nonalcoholic fatty liver disease: Optimizing liver outcomes

The growth in prevalence of obesity, type 2 diabetes and nonalcoholic fatty liver disease (NAFLD) has become one of the most important global health challenges. The three chronic diseases are closely linked in their epidemiology and pathophysiology. Currently, weight loss is the most effective treatment for NAFLD (even in the minority of patients with NAFLD who do not have obesity) and is recommended in all national and international guidelines. Accumulating evidence has shown that weight loss, whether achieved by diet and lifestyle interventions, bariatric surgery or pharmacotherapy, can improve biomarkers of NAFLD, as well as prevent progression and, in some cases, reverse fibrosis. There is a dose dependency of weight loss with NAFLD improvement. Pharmacotherapy with antiobesity medications, alone or in combination with intensive lifestyle interventions or other weight-loss drugs, is closing the efficacy gap between diet and exercise and weight-loss surgery in efficacy at reversing obesity. Given the importance of providing effective weight-loss treatment to patients with NAFLD, weight management services need to be made increasingly available and embedded within hepatology services. This narrative review addresses the evidence that weight loss optimizes liver outcomes in people with NAFLD.

Guidelines for Perioperative Care in Bariatric Surgery: Enhanced Recovery After Surgery (ERAS) Society Recommendations: A 2021 Update

Background

This is the second updated Enhanced Recovery After Surgery (ERAS®) Society guideline, presenting a consensus for optimal perioperative care in bariatric surgery and providing recommendations for each ERAS item within the ERAS® protocol.

Methods

A principal literature search was performed utilizing the Pubmed, EMBASE, Cochrane databases and ClinicalTrials.gov through December 2020, with particular attention paid to meta-analyses, randomized controlled trials and large prospective cohort studies. Selected studies were examined, reviewed and graded according to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. After critical appraisal of these studies, the group of authors reached consensus regarding recommendations.

Results

The quality of evidence for many ERAS interventions remains relatively low in a bariatric setting and evidence-based practices may need to be extrapolated from other surgeries.

Conclusion

A comprehensive, updated evidence-based consensus was reached and is presented in this review by the ERAS® Society.

Prehabilitation in adult patients undergoing surgery: an umbrella review of systematic reviews

BACKGROUND

The certainty that prehabilitation improves postoperative outcomes is not clear. The objective of this umbrella review (i.e. systematic review of systematic reviews) was to synthesise and evaluate evidence for prehabilitation in improving health, experience, or cost outcomes.

METHODS

We performed an umbrella review of prehabilitation systematic reviews. MEDLINE, Embase, Cochrane, Cumulative Index to Nursing and Allied Health Literature, PsycINFO, Joanna Briggs Institute's database, and Web of Science were searched (inception to October 20, 2020). We included all systematic reviews of elective, adult patients undergoing surgery and exposed to a prehabilitation intervention, where health, experience, or cost outcomes were reported. Evidence certainty was assessed using Grading of Recommendations Assessment, Development and Evaluation. Primary syntheses of any prehabilitation were stratified by surgery type.

RESULTS

From 1412 titles, 55 systematic reviews were included. For patients with cancer undergoing surgery who participate in any prehabilitation, moderate certainty evidence supports improvements in functional recovery. Low to very low certainty evidence supports reductions in complications (mixed, cardiovascular, and cancer surgery), non-home discharge (orthopaedic surgery), and length of stay (mixed, cardiovascular, and cancer surgery). There was low to very low certainty evidence that exercise prehabilitation reduces the risk of complications, non-home discharge, and length of stay. There was low to very low certainty evidence that nutritional prehabilitation reduces risk of complications, mortality, and length of stay.

CONCLUSIONS

Low certainty evidence suggests that prehabilitation may improve postoperative outcomes. Future low risk of bias, randomised trials, synthesised using recommended standards, are required to inform practice. Optimal patient selection, intervention design, and intervention duration must also be determined.

Elective Surgery in Adult Patients with Excess Weight: Can Preoperative Dietary Interventions Improve Surgical Outcomes? A Systematic Review

This systematic review summarises the literature regarding the impact of preoperative dietary interventions on non-bariatric surgery outcomes for patients with excess weight/obesity, a known risk factor for poor surgical outcomes. Four electronic databases were searched for non-bariatric surgery studies that evaluated the surgical outcomes of a preoperative diet that focused on weight/fat loss or improvement of liver steatosis. Meta-analysis was unfeasible due to the extreme heterogeneity of variables. Fourteen studies, including five randomised controlled trials, were selected. Laparoscopic cholecystectomy, hernia repair, and liver resection were most studied. Diet-induced weight loss ranged from 1.4 kg to 25 kg. Preoperative very low calorie diet (≤800 kcal) or low calorie diet (≤900 kcal) for one to three weeks resulted in: reduction in blood loss for two liver resection and one gastrectomy study (-27 to -411 mL, p < 0.05), and for laparoscopic cholecystectomy, reduction of six minutes in operating time (p < 0.05) and reduced difficulty of aspects of procedure (p < 0.05). There was no difference in length of stay (n = 7 studies). Preoperative ≤ 900 kcal diets for one to three weeks could improve surgical outcomes for laparoscopic cholecystectomy, liver resection, and gastrectomy. Multiple randomised controlled trials with common surgical outcomes are required to establish impact on other surgeries.

A Pilot Randomized Controlled Trial of a Partial Meal Replacement Preconception Weight Loss Program for Women with Overweight and Obesity

About half of Australian women have a body mass index in the overweight or obese range at the start of pregnancy, with serious consequences including preterm birth, gestational hypertension and diabetes, caesarean section, stillbirth, and childhood obesity. Trials to limit weight gain during pregnancy have had limited success and reducing weight before pregnancy has greater potential to improve outcomes. The PreBabe Pilot study was a randomised controlled pilot trial to assess the feasibility, acceptability and potential weight loss achieved using a commercial online partial meal replacement program, (MR) vs. telephone-based conventional dietary advice, (DA) for pre-conception weight-loss over a 10-week period. Women 18–40 years of age with a BMI ≥ 25 kg/m² planning pregnancy within the next 6 to 12 months were included in the study. All participants had three clinic visits with a dietitian and one obstetric consultation. In total, 50 women were enrolled in the study between June 2018 and October 2019–26 in MR and 24 in DA. Study retention at the end of 10 week intervention 81% in the MR arm and 75% in the DA arm. In the-intention-to-treat analysis, women using meal replacements lost on average 5.4 ± 3.1% body weight compared to 2.3 ± 4.2% for women receiving conventional advice (p = 0.029). Over 80% of women in the MR arm rated the support received as excellent, compared to 39% in the DA arm (p < 0.001). Women assigned to the MR intervention were more likely to achieve pregnancy within 12 months of the 10 week intervention (57% (12 of 21) women assigned to MR intervention vs. 22% (4 of 18) assigned to the DA group (p = 0.049) became pregnant). The findings suggest that a weight loss intervention using meal replacements in the preconception period was acceptable and may result in greater weight loss than conventional dietary advice alone.

Nutritional Assessment and Preparation for Adult Bariatric Surgery Candidates: Clinical Practice

Bariatric surgery (BS) has proven to be highly efficacious in the treatment of obesity and its comorbidities. However, careful patient selection is critical for its success. Thus, patients should undergo medical, behavioral, and nutritional assessment by a multidisciplinary team. From the nutritional point of view, BS candidates should undergo nutritional assessment, preparation, and education by a registered dietitian in the preoperative period. Currently, detailed specified and comprehensive information on these topics is lacking. The present narrative review aimed to summarize the available literature concerning both the preoperative nutritional assessment components and the preoperative nutritional preparation and education components of patients planning to undergo BS. Current literature indicates that proper management before BS should include a comprehensive nutritional assessment, in which it is advisable to perform a clinical interview to assess patients' medical background, weight management history, eating patterns and pathologies, oral health, physical activity habits, nutritional status, supplementation usage, BS knowledge, surgery expectations and anthropometric measurements. Nutritional preparation and educational strategies should include an individualized preoperative weight-loss nutrition program, improvement of glycemic control, micronutrients deficiencies correction, eating and lifestyle habits adaptation, physical activity initiation, and strengthening knowledge on obesity and BS. At this stage, more well-designed intervention and long-term cohort studies are needed in order to formulate uniform evidence-based nutritional guidelines for patients who plan to undergo BS, including populations at higher nutritional risk. Moreover, postoperative outcomes of presurgical nutritional intervention programs should be studied.

Nutrient and Food Intake of Participants in a Whole-Food Plant-Based Lifestyle Program

OBJECTIVE

We evaluated the nutrient adequacy of a well-planned supplemented whole-food plant-based (WFPB) diet as a component of an ongoing community lifestyle optimization program. We investigated the contributions of nutrients from foods and supplements and plant-based meal replacement (SMR) separately (foods, SMR) and combined (vs recommendations) as well as food group intake, both according to sex.

METHOD

Our cross-sectional study included 151 healthy, active participants (aged 39.6 years) who were on a Western-type diet when they voluntarily joined our WFPB lifestyle program (0.5-10 years ago). We assessed diet using 3-day weighed dietary records (foods, S, and MR). After we standardized nutrient intake to 2000 kcal/d, we calculated the contribution of macro- and micronutrients from foods and SMR separately and combined (foods + SMR) (vs central European Recommendations), as well as food group intake, both according to sex.

RESULTS

All macro- and micronutrient intake (total: from foods plus SMR) exceeded the reference values, except for calcium (95% and 82% in females and males) and vitamin D (both sexes, in summertime). Compared with male participants, female participants consumed (i.e., from foods and SMR together) significantly larger amounts of 23 (/25) micronutrients (8 [/25] from foods and 22 [/25] from SMR). The diet was primarily composed of the following (by mass in descending order): unprocessed vegetables/fruits, whole grains, legumes, potatoes, nuts/seeds, MR, and spices/herbs.

CONCLUSIONS

Participants in our WFPB lifestyle program ingested a nutrient-rich WFPB diet and targeted supplementation. The presented ongoing community WFPB lifestyle program ensures a healthy, balanced, and environment-friendly dietary pattern for participants who are compliant.

Dietary Intakes and Cardiovascular Health of Healthy Adults in Short-, Medium-, and Long-Term Whole-Food Plant-Based Lifestyle Program

An effective lifestyle strategy to reduce cardiovascular diseases risk (CVD) factors is needed. We examined the effects of a whole-food plant-based (WFPB) lifestyle program on dietary intake and cardiovascular (CV) risk factors in 151 adults (mean 39.6 (SD 12.5) years). Adherence was categorised into short-, medium- and long-term (years: (0.5-<2), (2-<5) and (5-10)), for both genders separately. Dietary intakes were assessed, fasting blood lipids and blood pressure (BP) were measured, and % participants reaching guideline recommended targets for LDL-cholesterol, triglycerides and BP in the primary CVD prevention was assessed. There were no statistically significant differences in intakes of energy and most nutrients among participants (both genders), that were short-, medium- and long term in our program. Diet was mainly composed of unprocessed vegetables/fruits, whole grains, legumes, potatoes, and nuts/seeds. LDL-cholesterol, triglycerides, systolic and diastolic BP were within targets for: 93%, 97%, 88% and 95% participants, respectively. In females (vs. males), total- and HDL-cholesterol were higher (mean): 3.8 (SD 0.7) vs. 3.4 (SD 0.9), p = 0.002 and 1.5 (SD 0.3) vs. 1.1 (SD 0.2) mmol/L, p < 0.001), systolic BP was lower (113 (SD 11) vs. 120 (SD 10) mmHg, p = 0.001), while there was no difference in diastolic BP (71 (SD 9) vs. 72 (SD 8) mmHg, p = 0.143). More females vs. males reached target triglycerides (99% vs. 91%, p = 0.021) and systolic BP (92% vs. 79%, p = 0.046), while similar females and males reached target LDL-cholesterol (94% vs. 91%, p = 0.500) and diastolic BP (93% vs. 100%, p = 0.107). Participation in our WFPB lifestyle program is associated with favourable dietary intakes, safety markers, and CV risk factor profiles.

Management of Diabetes in Patients Undergoing Bariatric Surgery

PURPOSE OF REVIEW

The number of bariatric surgeries for patients with type 1 or type 2 diabetes continues to grow. Clinicians are challenged to choose therapies that reach glycemic targets without inducing adverse effects in post-bariatric patients without published guidelines. This review evaluates data supporting the best strategies for diabetes management in patients undergoing bariatric surgery.

RECENT FINDINGS

Though few clinical trials have evaluated the safety and effectiveness of different glucose-lowering therapies following bariatric surgery, remission of diabetes or reduced medications is an established benefit of bariatric surgery. Adverse events including diabetic ketoacidosis in post-bariatric patients on sodium-glucose co-transporter 2 (SGLT2) inhibitors or inadequate insulin have been reported in patient's with both type 1 and type 2 diabetes. Metformin, glucagon-like peptide-1 (GLP-1) agonists, dipeptidyl peptidase-4 (DPP-4) inhibitors, SGLT2 inhibitors, insulin, and sulfonylureas have been used successfully in the perioperative period for other surgeries and guidelines recommend adjusting the doses of these medications especially in the perioperative period. Clinicians should favor weight-neutral or weight-loss promoting therapies in post-bariatric surgery patients such as medical nutrition therapy, metformin, GLP-1 agonists, SGLT2 inhibitors, and DPP-4 inhibitors.

Very-low-calorie ketogenic diet (VLCKD) in the management of metabolic diseases: systematic review and consensus statement from the Italian Society of Endocrinology (SIE)

BACKGROUND

Weight loss is a milestone in the prevention of chronic diseases associated with high morbility and mortality in industrialized countries. Very-low calorie ketogenic diets (VLCKDs) are increasingly used in clinical practice for weight loss and management of obesity-related comorbidities. Despite evidence on the clinical benefits of VLCKDs is rapidly emerging, some concern still exists about their potential risks and their use in the long-term, due to paucity of clinical studies. Notably, there is an important lack of guidelines on this topic, and the use and implementation of VLCKDs occurs vastly in the absence of clear evidence-based indications.

PURPOSE

We describe here the biochemistry, benefits and risks of VLCKDs, and provide recommendations on the correct use of this therapeutic approach for weight loss and management of metabolic diseases at different stages of life.

The Efficacy of Energy-Restricted Diets in Achieving Preoperative Weight Loss for Bariatric Patients: a Systematic Review

In bariatric practice, a preoperative weight loss of at least 5% is recommended. However, the hypocaloric diets prescribed vary and no consensus exists. This study examined the efficacy of preoperative diets in achieving 5% weight loss. From a systematic literature search, eight randomised controlled trials (n = 862) were identified. Half of the trials used a "very-low-calorie diet" whilst the rest employed a "low-calorie diet". Only five diets achieved ≥ 5% weight loss over varying durations and energy intakes. By inference, compliance with a 700-1050 kcal (2929-4393 kJ) diet, consisting of moderate carbohydrate, high protein and low/moderate fat, for 3 weeks is likely to achieve 5% weight loss. A low-carbohydrate diet (< 20 g/day) may achieve this target within a shorter duration. Additional research is required to validate these conclusions.

Dietary Management in the Immediate Preoperative Period of Bariatric Surgery: a National Overview : Bariatric Preoperative Diets

BACKGROUND

Although widely applied, there is no consensus about the characteristics of the diets prescribed in the immediate preoperative period of bariatric surgery (BS). The objective of this study was to perform a survey on preoperative dietary management in BS centers.

METHODS

This was a cross-sectional study with BS Brazilian centers. Only BS centers with certificate of excellence by Surgical Review Corporation were included. An electronic questionnaire was applied to assess details about the dietary management in the immediate preoperative period of BS.

RESULTS

Of the 15 centers invited, 80% (n = 12) answered the questionnaire. Preoperative weight loss was required to patients in all 12 centers. For 8.3% (n = 1), this request was applied to all patients; 91.7% (n = 11) of the centers requested weight loss in specific cases. Ten (83.3%) centers prescribed restrictive diets; none of these adopted a standard dietary protocol. The caloric value of the diets ranged from 800 to 2000 kcal/day. The duration of the diet ranged from 10 to 20 days in 40% (n = 4) of the centers and from 20 to 90 days in 60% (n = 6) of the centers. Dietary prescription was based on team consensus in 100% (n = 12) of the centers. In 33.3% (n = 4) of the centers, scientific evidence supporting dietary prescription was cited.

CONCLUSION

This study identified the frequent practice of requesting preoperative weight loss and the diversity of diets used in the immediate preoperative period by Brazilian BS centers. Future guideline proposal is needed on preoperative BS diets.

A 4-Week Preoperative Ketogenic Micronutrient-Enriched Diet Is Effective in Reducing Body Weight, Left Hepatic Lobe Volume, and Micronutrient Deficiencies in Patients Undergoing Bariatric Surgery: a Prospective Pilot Study

BACKGROUND

Before bariatric surgery (BS), moderate weight loss, left hepatic lobe volume reduction, and micronutrient deficiency (MD) identification and correction are desirable.

OBJECTIVES

The objective of this study was to assess the safety and the effectiveness of a 4-week preoperative ketogenic micronutrient-enriched diet (KMED) in reducing body weight (BW), left hepatic lobe volume, and correcting MD in patients scheduled for BS.

MATERIALS AND METHODS

In this prospective pilot study, a cohort of morbidly obese patients (n = 27, 17 females, 10 males) with a mean body mass index (BMI) of 45.2 kg/m² scheduled for BS underwent a 4-week preoperative KMED. Their BW, BMI, fat mass (FM), fat-free mass (FFM), resting metabolic rate (RMR), left hepatic lobe volume, micronutrient status, and biochemical and metabolic patterns were measured before and after the 4-week KMED. Patient compliance was assessed by validated questionnaires (3-day estimated food records and 72-h recall). Qualitative methods (5-point Likert questionnaire) were used to measure diet acceptability and side effects.

RESULTS

All patients completed the study. We observed highly significant decreases in BW (- 10.3%, p < 0.001, in males; - 8.2%, p < 0.001, in females), left hepatic lobe volume (- 19.8%, p < 0.001), and an amelioration of patient micronutrient status. All patients showed a high frequency of acceptability and compliance in following the diet. No adverse side effect was reported.

CONCLUSION

This study demonstrates that a 4-week preoperative KMED is safe and effective in reducing BW, left hepatic lobe volume, and correcting MD in obese patients scheduled for BS.

The Importance of Creating Habits and Routine

One of the greatest challenges to lifestyle medicine is patient adherence. Lifestyle diseases inherently require lifetime prevention and treatment. Therefore, adherence to lifestyle medicine recommendations must also be long-term. Long-term adherence implies that a routine incorporating health recommendations has been developed. Instead of focusing on the immediacy of adherence in lifestyle changes, health care providers could consider helping patients develop a routine to slowly incorporate those changes. This perspective may enable greater long-term adherence to lifestyle change recommendations.

Preoperative weight loss program involving a 20-day very low-calorie diet for obesity before laparoscopic gastrectomy for gastric cancer

INTRODUCTION

The increased visceral fat in patients with obesity can increase the technical difficulty of surgery. This study was performed to evaluate a preoperative 20-day very low-calorie diet for obesity before laparoscopic gastrectomy for gastric cancer.

METHODS

This prospective single-center study involved patients with obesity who were planning to undergo laparoscopic gastrectomy for gastric cancer. Obesity was defined according to the Japanese criteria: BMI ≥25 kg/m² or waist circumference ≥85 cm in men and ≥90 cm in women. The patients underwent a preoperative 20-day very low-calorie diet and received nutritional counseling. Weight loss, body composition, visceral fat mass, and operative outcomes were evaluated.

RESULTS

Thirty-three patients were enrolled from September 2013 to August 2015. Their median age was 71 years, and 78.8% were men. Their median bodyweight and BMI were 72.3 kg (range, 53.8-82.5 kg) and 26.0 kg/m² (range, 23.5-31.0 kg/m² ), respectively. The patients achieved a mean weight loss of 4.5% (95% confidence interval [CI]: 3.8-5.1), corresponding to 3.2 kg (95%CI: 2.7-3.7 kg). Body fat mass was significantly decreased by a mean of 2.5 kg (95%CI: 1.9-3.1), whereas skeletal muscle mass was unaffected (mean: -0.20 kg [95%CI: -0.55-0.15]). The visceral fat mass reduction rate was high as 16.8% (range, 11.6%-22.0%). All patients underwent laparoscopic gastrectomy as planned. Severe postoperative morbidity (Clavien-Dindo grade ≥III) was seen in only one patient (3.0%).

CONCLUSION

The preoperative 20-day very low-calorie diet weight loss program is promising for the treatment of obesity before laparoscopic gastrectomy for gastric cancer.

'The only chance of a normal weight life': A qualitative analysis of online forum discussions about bariatric surgery

Background

The only effective weight loss treatment for severe obesity is bariatric surgery, with Roux-en-Y gastric bypass being the most common method. Patients often have unrealistic expectations of surgery and expect a “miracle cure” even though the procedure requires major lifelong lifestyle changes. Most patients access information about the procedure online, and come into contact with others who have had the surgery.

Objective

The objective of this study was to describe shared values, feelings, and thoughts among visitors to a web-based forum for those undergoing bariatric surgery.

Methods

In this cross-sectional observation study using qualitative contents analysis, the material consisted of an online discussion forum thread about bariatric surgery, with 498 posts. These were saved in a document, read and re-read. Through coding of meaningful units of text, themes were established.

Results

Four themes were constructed during data analysis: a) A new life—anticipating dramatic changes of body and mind; b) Negotiating the system and playing the waiting game; c) A means to an end—managing the pre-operative diet; and d) Managing the attitudes of others. Posters described the process of bariatric surgery as a journey, riddled with roadblocks, setbacks and trials, but also with joy and expectations of a new life.

Conclusion

Professionals who encounter this group should be aware of their need for support throughout the process, and investigate the possibility of both pre- and postoperative support groups, either online or face-to-face. The results also show that the posters on the forum had very high, and often unrealistic, expectations on how the surgery would change their lives. It is important for those who encounter this group before surgery to be aware of this tendency and to take measures to ensure that patients undergo the surgery with realistic expectations.

Nutritional Recommendations for Adult Bariatric Surgery Patients: Clinical Practice

Bariatric surgery is currently the most effective treatment for morbid obesity and its associated metabolic complications. To ensure long-term postoperative success, patients must be prepared to adopt comprehensive lifestyle changes. This review summarizes the current evidence and expert opinions with regard to nutritional care in the perioperative and long-term postoperative periods. A literature search was performed with the use of different lines of searches for narrative reviews. Nutritional recommendations are divided into 3 main sections: 1) presurgery nutritional evaluation and presurgery diet and supplementation; 2) postsurgery diet progression, eating-related behaviors, and nutritional therapy for common gastrointestinal symptoms; and 3) recommendations for lifelong supplementation and advice for nutritional follow-up. We recognize the need for uniform, evidence-based nutritional guidelines for bariatric patients and summarize recommendations with the aim of optimizing long-term success and preventing complications.

Predictors of preoperative weight loss achievement in adult bariatric surgery candidates while following a low-calorie diet for 4 weeks

BACKGROUND

Achieving program-mandated preoperative weight loss poses a challenge for many bariatric surgery candidates. No systematic method exists to identify at-risk patients early in preoperative care.

OBJECTIVES

This study sought to explore predictors of preoperative weight loss achievement and to develop a treatment algorithm for guiding clinical decision-making.

SETTING

Greenville Health System, South Carolina.

METHODS

A retrospective chart review was conducted for 378 patients who followed a program-mandated low-calorie diet (LCD) for 4 weeks to achieve≥8% excess weight loss (EWL). Associations between weight loss achievement and patient demographic, nutrition, psychological, clinical, anthropometric, and treatment characteristics documented at 5 preoperative evaluation events were analyzed using logistic regression.

RESULTS

During the LCD, 62.7% of patients achieved≥8% EWL. Independent predictors of achievement (all P<.05) were male sex (OR 2.31, 95% CI 1.21-4.42), Caucasian race (OR 2.45, 95% CI 1.38-4.34), body mass index (BMI) at surgeon evaluation (50.0-59.9 kg/m²: OR .44, 95% CI .20-.97;≥60 kg/m²: OR .15, 95% CI .05-.42), number of co-morbidities (OR .83, 95% CI .74-.93), hypertension diagnosis (OR 2.42, 95% CI 1.42-4.13), prediet weight change (OR 1.08, 95% CI 1.01-1.16), and time between surgeon evaluation and preoperative LCD initiation (61-90 d: OR .46, 95% CI .23-.93).

CONCLUSION

Patients of female sex or non-Caucasian race; with a BMI≥50 kg/m², many co-morbidities, or no hypertension diagnosis at surgeon evaluation; who demonstrate prediet weight loss or extended wait time between surgeon evaluation and preoperative LCD initiation may be at risk for preoperative weight loss failure and may require preemptive diet modification to improve outcomes.