Malnutrition in patients with obesity: An overview perspective.

Malnutrition in patients with obesity presents a complex and often overlooked clinical challenge. Although obesity is traditionally associated with overnutrition and excessive caloric intake, it can also coincide with varying degrees of malnutrition. The etiopathogenesis of obesity is multifaceted and may arise from several factors such as poor diet quality, nutrient deficiencies despite excess calorie consumption, genetics, and metabolic abnormalities affecting nutrient absorption and utilization. Moreover, a chronic low-grade inflammatory state resulting from excess adipose tissue, commonly observed in obesity, can further exacerbate malnutrition by altering nutrient metabolism and increasing metabolic demands. The dual burden of obesity and malnutrition poses significant risks, including immune dysfunction, delayed wound healing, anemia, metabolic disturbances, and deficiencies in micronutrients such as vitamin D, iron, magnesium, and zinc, among others. Malnutrition is often neglected or not given enough attention in individuals with obesity undergoing rapid weight loss through aggressive caloric restriction, pharmacological therapies, and/or surgical interventions. These factors often exacerbate vulnerability to nutrition deficiencies. We advocate for healthcare practitioners to prioritize nutrition assessment and initiate medical intervention strategies tailored to address both excessive caloric intake and insufficient consumption of essential nutrients. Raising awareness among healthcare professionals and the general population about the critical role of adequate nutrition in caring for patients with obesity is vital for mitigating the adverse health effects associated with malnutrition in this population.

Safety of Same-Day Discharge after Bariatric Surgery: Retrospective 6-Year North American Analysis.

BACKGROUND: With increasing implementation of Enhanced Recovery After Surgery protocols and rising demand for inpatient hospital beds accentuated by COVID-19, there has been interest in same-day discharge (SDD) for bariatric surgery. The aim of this study was to determine the national trends, safety profile, and risk factors for complications of SDD for minimally invasive bariatric surgery. STUDY DESIGN: We analyzed the MBSAQIP database from 2016 to 2021 to characterize trends in SDD for minimally invasive bariatric operation. Multivariate logistic regression was performed on preoperative patient characteristics predictive of increased complications associated with SDD. A comparative analysis of postoperative outcomes within 30 days was performed for SDD and admission after 1:1 nearest neighbor propensity score matching for patient demographics and preoperative comorbidities. RESULTS: SDD increased from 2.4% in 2016 to 7.4% in 2021. Major preoperative factors associated with increased complications for SDD included Black race, history of MI, renal insufficiency, deep vein thrombosis, and smoking. SDD for Roux-en-Y gastric bypass had 72% increased risk of postoperative complications compared with sleeve gastrectomy. The overall major complications were lower in SDD cohort vs admission cohort (odds ratio [OR] 0.62, p < 0.01). However, there was a significant increase in deaths within 30 days (OR 2.11, p = 0.01), cardiac arrest (OR 2.73; p < 0.01), and dehydration requiring treatment (OR 1.33; p < 0.01) in SDD cohort compared with admission cohort. CONCLUSIONS: Nationally, there has been a rise in SDD for bariatric operation from 2016 to 2021. Matched analysis demonstrates that SDD is associated with a significantly higher mortality rate. Additionally, the risk of complications with SDD is higher for RYGB compared with sleeve gastrectomy. Therefore, further studies are required to appropriately select patients for whom bariatric surgery can be safely performed as an outpatient.

Concomitant use of monoamine oxidase inhibitor and tyrosine in parenteral nutrition.

Monoamine oxidase inhibitors (MAOIs) prevent the breakdown of tyramine in the body, and can cause a sudden increase in blood pressure with significant tyramine build up. This phenomenon, when it occurs, is known as tyramine pressor response. It is unknown if tyrosine administered in parenteral nutrition (PN) leads to tyramine build-up with concomitant use of MAOIs. It is also unknown if PN patients who are taking MAOI are at risk for the tyramine pressor response. This is a theoretical possibility as tyrosine endogenously undergoes decarboxylation to produce tyramine. We describe our experience with a 67-year-old woman with severe depression who was on the MAOI, transdermal selegiline. Her clinical course was complicated by an inability to take adequate per oral (PO) intake and she met criteria for unspecified severe protein-calorie-malnutrition in the context of social or environmental circumstances. Therefore, she required PN initiation. PlenamineTM (B. Braun, Bethlehem, PA, USA) was used as the amino acid source in the PN, which contains 39 mg of tyrosine per 100 ml of solution. The patient was monitored closely for any signs of hypertensive crisis while on PN and selegiline. She safely tolerated the combined therapy without any side effects. This is the first documented report of co-administration of PN containing tyrosine along with a MAOI. Our findings suggest that the dose of selegiline used in this patient can be co-administered safely in the setting of PN. However, further study is needed to verify our findings beyond this one patient. In conclusion, we recommend initiating PN and increasing it to goal in patients taking MAOIs, gradually, while monitoring for hypertensive crisis given the theoretical possibility of the tyramine pressor response.

Nephrogenic Calciphylaxis Arising after Bariatric Surgery: A Case Series.

Nephrogenic calciphylaxis is associated with multiple risk factors including long-term dialysis dependence, hyperphosphatemia, hypercalcemia, parathyroid hormone derangements, vitamin K deficiency, obesity, diabetes mellitus, warfarin use, and female sex. Bariatric surgery is known to cause altered absorption, leading to mineral and hormonal abnormalities in addition to nutritional deficiency. Prior case reports on calciphylaxis development following bariatric surgery have been published, though are limited in number. We report a case series of five bariatric patients from a single institution who developed nephrogenic calciphylaxis between 2012 and 2018. These patients had a history of bariatric surgery, and at the time of calciphylaxis diagnosis, demonstrated laboratory abnormalities associated with surgery including hypercalcemia (n = 3), hyperparathyroidism (n = 2), hypoalbuminemia (n = 5), and vitamin D deficiency (n = 5), in addition to other medication exposures such as vitamin D supplementation (n = 2), calcium supplementation (n = 4), warfarin (n = 2), and intravenous iron (n = 1). Despite the multifactorial etiology of calciphylaxis and the many risk factors present in the subjects of this case series, we submit that bariatric surgery represents an additional potential risk factor for calciphylaxis directly stemming from the adverse impact of malabsorption and overuse of therapeutic supplementation. We draw attention to this phenomenon to encourage early consideration of calciphylaxis in the differential for painful skin lesions arising after bariatric surgery as swift intervention is essential for these high-risk patients.

Procedure Matters in Gender-Associated Outcomes following Metabolic-Bariatric Surgery: Five Year North American Matched Cohort Analysis.

PURPOSE: Eighty percent of patients who undergo metabolic-bariatric surgery self-identify as female. It is unclear why there is a disparate use of metabolic-bariatric surgery by men compared to women given the widely accepted safety of weight loss surgical procedures. One possible explanation is that post-operative outcomes of metabolic-bariatric surgery have been shown to be worse for men compared to women in prior studies. The purpose of this study was to characterize the impact of gender on outcomes of metabolic-bariatric surgery using the most recent MBSAQIP data registry from 2017-2021. MATERIALS AND METHODS: Data entered into the MBSAQIP registry from 2017-2021 for patients who underwent primary metabolic-bariatric surgery procedures was identified. The data was then matched for multiple pre-operative factors and comorbidities, and outcomes were assessed and compared for men and women. RESULTS: No significant difference was observed in anastomotic leak, wound complications, and bleeding between men and women. However, men were at 0.15% (p < 0.01) higher risk of major complications (encompassing unplanned ICU admission, deep organ space infection, unplanned intubation, bleeding, anastomotic leak, sepsis, pneumonia, myocardial infarction, cardiac arrest, cerebrovascular accident, pulmonary embolism, reoperation, and death) compared to women. While men had higher major complications compared to women for SG, there was no significant difference between the two cohorts for RYGB, BPD and LAGB. CONCLUSION: While there are some differences in outcomes between male and female patients, the difference is modest. Male gender should not be considered a high-risk factor for all bariatric procedures and cannot explain the difference in utilization of metabolic-bariatric surgery by men compared to women.

Cost-Effectiveness of Surgical Weight-Loss Interventions for Patients With Knee Osteoarthritis and Class III Obesity.

OBJECTIVE: Class III obesity (body mass index [BMI] ≥40 kg/m2 ) is associated with worse knee pain and total knee replacement (TKR) outcomes. Because bariatric surgery yields sustainable weight loss for individuals with BMI ≥40 kg/m2 , our objective was to establish the value of Roux-en-Y gastric bypass (RYGB) and laparoscopic sleeve gastrectomy (LSG) in conjunction with usual care for knee osteoarthritis (OA) patients with BMI ≥40 kg/m2 . METHODS: We used the Osteoarthritis Policy model to assess long-term clinical benefits, costs, and cost-effectiveness of RYGB and LSG. We derived model inputs for efficacy, costs, and complications associated with these treatments from published data. Primary outcomes included quality-adjusted life-years (QALYs), lifetime costs, and incremental cost-effectiveness ratios (ICERs), all discounted at 3%/year. This analysis was conducted from a health care sector perspective. We performed sensitivity analyses to evaluate uncertainty in input parameters. RESULTS: The usual care + RYGB strategy increased the quality-adjusted life expectancy by 1.35 years and lifetime costs by $7,209, compared to usual care alone (ICER = $5,300/QALY). The usual care + LSG strategy yielded less benefit than usual care + RYGB and was dominated. Relative to usual care alone, both usual care + RYGB and usual care + LSG reduced opioid use from 13% to 4%, and increased TKR usage from 30% to 50% and 41%, respectively. For cohorts with BMI between 38 and 41 kg/m2 , usual care + LSG dominated usual care + RYGB. In the probabilistic sensitivity analysis, at a willingness-to-pay threshold of $50,000/QALY, usual care + RYGB and usual care + LSG were cost-effective in 70% and 30% of iterations, respectively. CONCLUSION: RYGB offers good value among knee OA patients with BMI ≥40 kg/m2 , while LSG may provide good value among those with BMI between 35 and 41 kg/m2 .

Cost-Effectiveness of Weight-Loss Interventions Prior to Total Knee Replacement for Patients With Class III Obesity.

OBJECTIVE: Class III obesity (body mass index >40 kg/m2 ) is associated with higher complications following total knee replacement (TKR), and weight loss is recommended. We aimed to establish the cost-effectiveness of Roux-en-Y gastric bypass (RYGB), laparoscopic sleeve gastrectomy (LSG), and lifestyle nonsurgical weight loss (LNSWL) interventions in knee osteoarthritis patients with class III obesity considering TKR. METHODS: Using the Osteoarthritis Policy model and data from published literature to derive model inputs for RYGB, LSG, LNSWL, and TKR, we assessed the long-term clinical benefits, costs, and cost-effectiveness of weight-loss interventions for patients with class III obesity considering TKR. We assessed the following strategies with a health care sector perspective: 1) no weight loss/no TKR, 2) immediate TKR, 3) LNSWL, 4) LSG, and 5) RYGB. Each weight-loss strategy was followed by annual TKR reevaluation. Primary outcomes were cost, quality-adjusted life expectancy (QALE), and incremental cost-effectiveness ratios (ICERs), discounted at 3% per year. We conducted deterministic and probabilistic sensitivity analyses to examine the robustness of conclusions to input uncertainty. RESULTS: LSG increased QALE by 1.64 quality-adjusted life-years (QALYs) and lifetime medical costs by $17,347 compared to no intervention, leading to an ICER of $10,600/QALY. RYGB increased QALE by 0.22 and costs by $4,607 beyond LSG, resulting in an ICER of $20,500/QALY. Relative to immediate TKR, LSG and RYGB delayed and decreased TKR utilization. In the probabilistic sensitivity analysis, RYGB was cost-effective in 67% of iterations at a willingness-to-pay threshold of $50,000/QALY. CONCLUSION: For patients with class III obesity considering TKR, RYGB provides good value while immediate TKR without weight loss is not economically efficient.

Comparison of Bariatric Branded Chewable Multivitamin/Multimineral Formulations to the 2016 American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines.

Postoperative vitamin and mineral supplementation are integral components of the management of the weight loss surgery patient. Supplements differ in type, amount, and salt form. No recent publication has compared bariatric branded commercially available products with current practice guidelines. Registered dietitians belonging to the New England Bariatric Dietitians LinkedIn group were surveyed to identify their recommendation practices. These results were then used to compare and discuss in a comprehensive fashion the most widely recommended bariatric branded chewable supplements to the 2016 American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines.

Under-Recognizing Malnutrition in Hospitalized Obese Populations: The Real Paradox.

PURPOSE OF REVIEW: Obesity and malnutrition are frequently encountered in the hospitalized population. Although malnutrition associated with low or normal body mass index (BMI) is easily identified, malnutrition in obese patients goes frequently unrecognized as their fat mass masks underlying muscle mass deterioration. The purpose of this review is to explore if malnutrition has been studied in the obese hospitalized population and if that may be one of the reasons for the variable results in the obesity outcome data. RECENT FINDINGS: Various studies have shown a conflicting association between obesity and outcomes in hospitalized patient population. Most prior studies used BMI alone as an indicator of obesity and although some recent studies have included body fat percentage, muscle mass, and functional status, they still showed variable outcomes. Unfortunately, there are not many studies that looked into nutrition status specifically in obese patients to study the outcomes. Studies evaluating clinical outcomes in obese patients showed a wide range of outcomes; some showed a protective effect while others were neutral. We explored recent data about obesity, malnutrition, and outcomes, where researchers more precisely defined malnutrition and obesity to determine health outcomes.

Pathophysiology of Critical Illness and Role of Nutrition.

Critical illness is a hypercatabolic state. It has been hypothesized that timely and adequate nutrition support may optimize the host response and thereby minimize nutritionally related complications while improving overall outcome. Any illness in due course can lead to a malnourished state-critical illness can worsen this state as patients may become immunocompromised and unable to mount an adequate inflammatory response and therefore susceptible to poor outcomes. Data indicate that prevalence of malnutrition in the ICU ranges from 38% to 78% and is independently associated with poor outcomes. Hence, exploring the role of nutrition as a way to mitigate critical illness is important. In this review, the basic pathophysiology of critical illness and how it alters carbohydrate, protein, and fat metabolism are discussed. This is followed by a discussion of malnutrition and how it affects patient and hospital outcomes. Finally, a summary of the available evidence regarding nutrition support and its impact on outcomes are provided. This review is not intended to provide practice-based guidelines; instead, it intends to highlight available data on the role of nutrition support in critically ill patients.

Malnutrition, Critical Illness Survivors, and Postdischarge Outcomes: A Cohort Study.

BACKGROUND: We hypothesized that preexisting malnutrition in patients who survived critical care would be associated with adverse outcomes following hospital discharge. METHODS: We performed an observational cohort study in 1 academic medical center in Boston. We studied 23,575 patients, aged ≥18 years, who received critical care between 2004 and 2011 and survived hospitalization. RESULTS: The exposure of interest was malnutrition determined at intensive care unit (ICU) admission by a registered dietitian using clinical judgment and on data related to unintentional weight loss, inadequate nutrient intake, and wasting of muscle mass and/or subcutaneous fat. The primary outcome was 90-day postdischarge mortality. Secondary outcome was unplanned 30-day hospital readmission. Adjusted odds ratios were estimated by logistic regression models adjusted for age, race, sex, Deyo-Charlson Index, surgical ICU, sepsis, and acute organ failure. In the cohort, the absolute risk of 90-day postdischarge mortality was 5.9%, 11.7%, 15.8%, and 21.9% in patients without malnutrition, those at risk of malnutrition, nonspecific malnutrition, and protein-energy malnutrition, respectively. The odds of 90-day postdischarge mortality in patients at risk of malnutrition, nonspecific malnutrition, and protein-energy malnutrition fully adjusted were 1.77 (95% confidence interval [CI], 1.23-2.54), 2.51 (95% CI, 1.36-4.62), and 3.72 (95% CI, 2.16-6.39), respectively, relative to patients without malnutrition. Furthermore, the presence of malnutrition is a significant predictor of the odds of unplanned 30-day hospital readmission. CONCLUSIONS: In patients treated with critical care who survive hospitalization, preexisting malnutrition is a robust predictor of subsequent mortality and unplanned hospital readmission.

Impact of Spanish-language information sessions on Spanish-speaking patients seeking bariatric surgery.

BACKGROUND: Bariatric centers frequently provide preoperative educational programs to inform patients about the risks and benefits of weight loss surgery. However, most programs are conducted in English, which may create barriers to effective treatment and access to care for non-English speaking populations. To address this concern, we instituted a comprehensive Spanish-language education program consisting of preoperative information and group nutrition classes conducted entirely in, and supported with Spanish-language materials. OBJECTIVES: The primary aim was to examine the effect of this intervention on Spanish-speaking patients' decision to undergo surgery in a pilot study. SETTING: University Hospital/Community Health Center, United States. METHODS: Three cohorts of patients seeking bariatric surgery between January 1, 2011 and March 31, 2012 were identified: 1) primary English speakers attending English-language programs ("English-English"); 2) primary Spanish speakers attending Spanish-language programs ("Spanish-Spanish"); and 3) primary Spanish speakers attending English-speaking programs with the assistance of a Spanish-to-English translator ("Spanish-English"). RESULTS: 26% of the English-English cohort ultimately underwent surgery compared with only 12% of the Spanish-Spanish cohort (P = .009). Compared with the English-English group, time to surgery was 35 days longer for the Spanish-Spanish and 185 days longer for the Spanish-English group (both P< .001). CONCLUSION: Spanish-speaking patients were less likely to undergo bariatric surgery regardless of the language in which educational sessions are provided. For those choosing surgery, providing Spanish-language sessions can shorten time to surgery. A barrier to effective obesity treatment may exist for Spanish speakers, which may be only partially overcome by providing support in Spanish.

Metabolites Associated With Malnutrition in the Intensive Care Unit Are Also Associated With 28-Day Mortality.

BACKGROUND: We hypothesized that metabolic profiles would differ in critically ill patients with malnutrition relative to those without. MATERIALS AND METHODS: We performed a prospective cohort study on 85 adult patients with systemic inflammatory response syndrome or sepsis admitted to a 20-bed medical intensive care unit (ICU) in Boston. We generated metabolomic profiles using gas and liquid chromatography and mass spectroscopy. We followed this by logistic regression and partial least squares discriminant analysis to identify individual metabolites that were significant. We then interrogated the entire metabolomics profile using metabolite set enrichment analysis and network model construction of chemical-protein target interactions to identify groups of metabolites and pathways that were differentiates in patients with and without malnutrition. RESULTS: Of the cohort, 38% were malnourished at admission to the ICU. Metabolomic profiles differed in critically ill patients with malnutrition relative to those without. Ten metabolites were significantly associated with malnutrition ( P < .05). A parsimonious model of 5 metabolites effectively differentiated patients with malnutrition (AUC = 0.76), including pyroglutamine and hypoxanthine. Using pathway enrichment analysis, we identified a critical role of glutathione and purine metabolism in predicting nutrition. Nutrition status was associated with 28-day mortality, even after adjustment for known phenotypic variables associated with ICU mortality. Importantly, 7 metabolites associated with nutrition status were also associated with 28-day mortality. CONCLUSION: Malnutrition is associated with differential metabolic profiles early in critical illness. Common to all of our metabolome analyses, glutathione and purine metabolism, which play principal roles in cellular redox regulation and accelerated tissue adenosine triphosphate degradation, respectively, were significantly altered with malnutrition.

An Effort to Develop an Algorithm to Target Abdominal CT Scans for Patients After Gastric Bypass.

Abdominal CT (abdCT) scans are frequently ordered for Roux-en-Y gastric bypass (RYGB) patients presenting to the emergency department (ED) with abdominal pain, but often do not reveal intra-abdominal pathology. We aimed to develop an algorithm for rational ordering of abdCTs. We retrospectively reviewed our institution's RYGB patients presenting acutely with abdominal pain, documenting clinical and laboratory data, and scan results. Associations of clinical parameters to abdCT results were examined for outcome predictors. Of 1643 RYGB patients who had surgery between 2005 and 2015, 355 underwent 387 abdCT scans. Based on abdCT, 48 (12 %) patients required surgery and 86 (22 %) another intervention. No clinical or laboratory parameter predicted imaging results. Imaging decisions for RYGB patients do not appear to be amenable to a simple algorithm, and patient work-up should be based on astute clinical judgment.

Safety and efficacy of single-stage conversion of failed adjustable gastric band to laparoscopic Roux-en-Y gastric bypass: a case-control study.

BACKGROUND: We conducted the following study to evaluate the safety and efficacy of single-stage conversion of failed laparoscopic adjustable gastric band (LAGB) to laparoscopic Roux-en-Y gastric bypass (LRYGB) as compared to a cohort of primary LRYGB patients. METHODS: A single-institution, prospectively maintained bariatric database was used to retrospectively identify consecutive patients who underwent single-stage removal of LAGB with concomitant conversion to LRYGB between the years of 2007 and 2013. The study cohort was matched 1:1 for age, gender, body mass index (BMI), and approximate date of operation to patients who underwent primary LRYGB. Primary endpoints were operative time, complication rate, length of hospital stay (LOS), and percent excess BMI lost (%EBMIL) at 24-month follow-up. RESULTS: Ninety-four conversion patients met inclusion criteria. There were no statistically significant differences in the mean LOS (3.1 vs. 3.0 days, p = 0.97) or the major complication rate (3.2 vs. 1.1 %, p = 0.62) at 30 days postoperatively. Likewise, 30-day minor complication rates, including readmission, were similar between groups (7.5 vs. 6.4 %, p = 0.77). The average operative time was significantly longer for conversion compared to primary LRYGB (193.5 vs. 132 min; p < 0.01). At most recent follow-up after conversion or primary LRYGB, median %EBMIL was 61.3 and 77.3 % (p < 0.01), percent total weight loss was 23.6 and 30.5 % (p < 0.01), and percent change in BMI was 23.4 and 30.5 % (p < 0.01), respectively. Median follow-up time was 17 and 18.6 months after conversion and primary LRYGB, respectively. CONCLUSION: Single-stage conversion of LAGB to LRYGB is safe with an acceptable complication rate and similar LOS compared to primary LRYGB.

Reproductive Outcomes Differ Following Roux-en-Y Gastric Bypass and Adjustable Gastric Band Compared with Those of an Obese Non-Surgical Group.

BACKGROUND: Little is known about how bariatric surgery type may impact reproductive health outcomes. Our objective was to determine differences in infertility and birth outcomes among women who underwent Roux-en-Y gastric bypass (RYGB), adjustable gastric band (AGB), and an obese non-surgical group. METHODS: Women aged 18-45 who were evaluated for bariatric surgery were invited to complete a survey. Pre- and post-surgery outcomes were compared among women who underwent RYGB vs. AGB and to those of obese women who decided against surgery. Outcomes included infertility, time to conception from first attempt, use of infertility services, pregnancy, live birth, and birth weights. Logistic and linear regression, controlling for age, BMI, weight, and pregnancy history, were used to calculate odds ratios (ORs) and beta-coefficients with 95 % confidence intervals (CIs). RESULTS: Two-hundred nineteen surveys were completed. RYGB resulted in a reduction in menstrual cycle irregularity after surgery compared to before (OR = 0.21, CI = 0.07-0.61). For first-pregnancy outcomes, there were lower odds of term birth after RYGB than before (OR = 0.21, CI = 0.05-0.90) and increased odds of miscarriage after RYGB compared to the no-surgery group (OR = 9.81, CI = 1.12-85.71). We found lower odds of live birth after AGB than before (OR = 0.19, CI = 0.05-0.73). Birth weight was significantly lower after RYGB but not AGB (p < 0.01). CONCLUSIONS: This small study suggests that the impact of bariatric surgery may vary by procedure type and impact menstrual regularity, live birth, and offspring birth weight. These results should be considered pilot data and support performance of a prospective study to fully investigate these preliminary findings.

Validation of the Society of Critical Care Medicine and American Society for Parenteral and Enteral Nutrition Recommendations for Caloric Provision to Critically Ill Obese Patients: A Pilot Study.

BACKGROUND: The Society of Critical Care Medicine (SCCM) and American Society for Parenteral and Enteral Nutrition (ASPEN) recommend that obese, critically ill patients receive 11-14 kcal/kg/d using actual body weight (ABW) or 22-25 kcal/kg/d using ideal body weight (IBW), because feeding these patients 50%-70% maintenance needs while administering high protein may improve outcomes. It is unknown whether these equations achieve this target when validated against indirect calorimetry, perform equally across all degrees of obesity, or compare well with other equations. METHODS: Measured resting energy expenditure (MREE) was determined in obese (body mass index [BMI] ≥30 kg/m(2)), critically ill patients. Resting energy expenditure was predicted (PREE) using several equations: 12.5 kcal/kg ABW (ASPEN-Actual BW), 23.5 kcal/kg IBW (ASPEN-Ideal BW), Harris-Benedict (adjusted-weight and 1.5 stress-factor), and Ireton-Jones for obesity. Correlation of PREE to 65% MREE, predictive accuracy, precision, bias, and large error incidence were calculated. RESULTS: All equations were significantly correlated with 65% MREE but had poor predictive accuracy, had excessive large error incidence, were imprecise, and were biased in the entire cohort (N = 31). In the obesity cohort (n = 20, BMI 30-50 kg/m(2)), ASPEN-Actual BW had acceptable predictive accuracy and large error incidence, was unbiased, and was nearly precise. In super obesity (n = 11, BMI >50 kg/m(2)), ASPEN-Ideal BW had acceptable predictive accuracy and large error incidence and was precise and unbiased. CONCLUSIONS: SCCM/ASPEN-recommended body weight equations are reasonable predictors of 65% MREE depending on the equation and degree of obesity. Assuming that feeding 65% MREE is appropriate, this study suggests that patients with a BMI 30-50 kg/m(2) should receive 11-14 kcal/kg/d using ABW and those with a BMI >50 kg/m(2) should receive 22-25 kcal/kg/d using IBW.