Obesity preclinical elective: a qualitative thematic analysis of student feedback.

BACKGROUND: Education about the prevalent chronic disease of obesity is still minimal and variable in medical school curricula. In a student-led effort with faculty support, the authors designed and implemented an obesity medicine elective at Case Western Reserve University School of Medicine (CWRU). The 10-week elective, taught by seven physicians and one dietitian, was offered in January 2023 to medical students and included: weekly lectures, an interactive session with a patient, shadowing in obesity medicine practices, attendance at a distance-learning intensive behavioral lifestyle program, student presentations, and a final written reflection. The purpose of this study was to analyze the elective reflections and identify themes about the elective's value and areas to improve. METHODS: The authors analyzed reflections from the 20 medical students that completed the elective via qualitative thematic analysis. The analysis was performed using the Braun and Clarke six-phase framework: (1) become familiar with the data, (2) generate initial codes, (3) search for themes, (4) review themes, (5) define themes, and (6) write-up. RESULTS: The themes identified were improved: (1) understanding of obesity as a chronic disease, (2) knowledge about treatment options for obesity (3) confidence in compassionate obesity counseling skills, and (4) skills to confront weight bias. Theme (5) consisted of highlights (hearing from experts, practicing evidence-based medicine, and interacting with patients), and areas to improve (session length, presentation format, more peer-to-peer interaction, and more diverse patient interactions). CONCLUSIONS: Medical student assessments of a new obesity medicine elective described improved attitudes, knowledge, and skills to address obesity and obesity bias. Students were very satisfied and contributed ideas for improvements. This elective structure and evaluation method is a feasible model to provide medical students with meaningful experiences related to obesity.

Preclinical obesity curriculum: audit, implementation, and evaluation.

BACKGROUND: This study aimed to (1) evaluate the current status of obesity education at Case Western Reserve University School of Medicine (CWRU) (2), introduce a comprehensive first-year curriculum on obesity, and (3) assess the impact of the curriculum on self-reported attitudes and knowledge regarding obesity among first-year medical students. METHODS: The preclinical curriculum at CWRU was reviewed to determine the degree of coverage of Obesity Medicine Education Collaborative (OMEC) competencies for healthcare professionals, and recommendations were provided for revising the curriculum to better adhere to these evidence-based competencies. A survey on obesity attitudes and knowledge was given before and after the implementation of the new curriculum to measure intervention-related changes. Changes in obesity attitudes and knowledge were compared (1) before and after the intervention for the class of 2025 and (2) after the intervention for the class of 2025 to a historical cohort that did not receive the intervention. RESULTS: Among the 27 competencies examined in the audit, 55% were unmet and 41% were partially met. Of 186 first-year medical students (M1s), 29 (16%) completed the baseline survey and 26 (14%) completed the post-intervention survey. Following the intervention, there was a notable improvement in attitudes and knowledge regarding obesity. Specifically, there was a significant decrease in the belief that obesity is caused by poor personal choices, and knowledge of obesity in fourteen out of fifteen areas showed significant improvement from pre- to post-intervention. Additionally, obesity attitudes and knowledge were significantly better post-intervention when compared to the historical cohort. CONCLUSIONS: The improvements made to the preclinical curriculum through this project improved obesity attitudes and knowledge among first-year medical students. This method provides a practical approach for evaluating and enhancing obesity education in medical school curricula.

Benchmarking of provider competencies and current training for prevention and management of obesity among family medicine residency programs: a cross-sectional survey.

BACKGROUND: U.S. physicians lack training in caring for patients with obesity. For family medicine, the newly developed Obesity Medicine Education Collaborative (OMEC) competencies provide an opportunity to compare current training with widely accepted standards. We aimed to evaluate the current state of obesity training in family medicine residency programs. METHODS: We conducted a study consisting of a cross-sectional survey of U.S. family medicine residency program leaders. A total of 735 directors (including associate/assistant directors) from 472 family medicine residency programs identified from the American Academy of Family Physicians public directory were invited via postal mail to complete an online survey in 2018. RESULTS: Seventy-seven program leaders completed surveys (16% response rate). Sixty-four percent of programs offered training on prevention of obesity and 83% provided training on management of patients with obesity; however, 39% of programs surveyed reported not teaching an approach to obesity management that integrates clinical and community systems as partners, or doing so very little. Topics such as behavioral aspects of obesity (52%), physical activity (44%), and nutritional aspects of obesity (36%) were the most widely covered (to a great extent) by residency programs. In contrast, very few programs extensively covered pharmacological treatment of obesity (10%) and weight stigma and discrimination (14%). Most respondents perceived obesity-related training as very important; 65% of the respondents indicated that expanding obesity education was a high or medium priority for their programs. Lack of room in the curriculum and lack of faculty expertise were reported as the greatest barriers to obesity education during residency. Only 21% of the respondents perceived their residents as very prepared to manage patients with obesity at the end of the residency training. CONCLUSION: Family medicine residency programs are currently incorporating recommended teaching to address OMEC competencies to a variable degree, with some topic areas moderately well represented and others poorly represented such as pharmacotherapy and weight stigma. Very few program directors report their family medicine residents are adequately prepared to manage patients with obesity at the completion of their training. The OMEC competencies could serve as a basis for systematic obesity training in family medicine residency programs.

Low priority of obesity education leads to lack of medical students' preparedness to effectively treat patients with obesity: results from the U.S. medical school obesity education curriculum benchmark study.

BACKGROUND: Physicians are currently unprepared to treat patients with obesity, which is of great concern given the obesity epidemic in the United States. This study sought to evaluate the current status of obesity education among U.S. medical schools, benchmarking the degree to which medical school curricula address competencies proposed by the Obesity Medicine Education Collaborative (OMEC). METHODS: Invitations to complete an online survey were sent via postal mail to 141 U.S. medical schools compiled from Association of American Medical Colleges. Medical school deans and curriculum staff knowledgeable about their medical school curriculum completed online surveys in the summer of 2018. Descriptive analyses were performed. RESULTS: Forty of 141 medical schools responded (28.4%) and completed the survey. Only 10.0% of respondents believe their students were "very prepared" to manage patients with obesity and one-third reported that their medical school had no obesity education program in place and no plans to develop one. Half of the medical schools surveyed reported that expanding obesity education was a low priority or not a priority. An average of 10 h was reported as dedicated to obesity education, but less than 40% of schools reported that any obesity-related topic was well covered (i.e., to a "great extent"). Medical students received an adequate education (defined as covered to at least "some extent") on the topics of biology, physiology, epidemiology of obesity, obesity-related comorbidities, and evidence-based behavior change models to assess patient readiness for counseling (range: 79.5 to 94.9%). However, in approximately 30% of the schools surveyed, there was little or no education in nutrition and behavioral obesity interventions, on appropriate communication with patients with obesity, or pharmacotherapy. Lack of room in the curriculum was reported as the greatest barrier to incorporating obesity education. CONCLUSIONS: Currently, U.S. medical schools are not adequately preparing their students to manage patients with obesity. Despite the obesity epidemic and high cost burden, medical schools are not prioritizing obesity in their curricula.

Obesity Coverage on Medical Licensing Examinations in the United States. What Is Being Tested?

Phenomenon. As one of the most common chronic disease affecting adults and children, obesity is a major contributor to noncommunicable diseases, both nationally and globally. Obesity adversely affects every organ system, and as such it is imperative that the United States Medical Licensing Examination (USMLE) adequately assesses students' knowledge about the science and practice of obesity management. The purpose of this study was to evaluate the coverage and distribution of obesity-related items on the three USMLE Step examinations. APPROACH: Examination items that included obesity-related keywords were identified by National Board of Medical Examiners (NBME) staff. A panel of 6 content experts evaluated all items and coded obesity-relevant items using the American Board of Obesity Medicine (ABOM) test outline rubric into 4 domains and 107 subdomains. FINDINGS: There were 802 multiple-choice items containing obesity-related keywords identified by NBME, of which 289 (36%) were identified as being relevant to obesity and were coded into appropriate domains and subdomains. Among the individual domains, the Diagnosis & Evaluation domain comprised most of the items (174) for all 3 Step examinations. Fifty-eight percent of items were represented by 4 of 17 organ systems, and 80% of coded items were represented by 6 ABOM subdomains. The majority of obesity-coded items pertained to the diagnosis and management of obesity-related comorbid conditions rather than addressing the prevention, diagnosis, or management of obesity itself. Insights. The most important concepts of obesity prevention and treatment were not represented on the Step exams. Exam items primarily addressed the diagnosis and treatment of obesity-related comorbid conditions instead of obesity itself. The expert review panel identified numerous important obesity-related topics that were insufficiently addressed or entirely absent from the examinations. The reviewers recommend that the areas identified for improvement may promote a more balanced testing of knowledge in obesity.

Nutritional considerations with antiobesity medications.

The improved efficacy and generally favorable safety profile of recently approved and emerging antiobesity medications (AOMs), which result in an average weight reduction of ≥15%, represent significant advancement in the treatment of obesity. This narrative review aims to provide practical evidence-based recommendations for nutritional assessment, management, and monitoring of patients treated with AOMs. Prior to treatment, clinicians can identify preexisting nutritional risk factors and counsel their patients on recommended intakes of protein, dietary fiber, micronutrients, and fluids. During treatment with AOMs, ongoing monitoring can facilitate early recognition and management of gastrointestinal symptoms or inadequate nutrient or fluid intake. Attention should also be paid to other factors that can impact response to treatment and quality of life, such as physical activity and social and emotional health. In the context of treatment with AOMs, clinicians can play an active role in supporting their patients with obesity to improve their health and well-being and promote optimal nutritional and medical outcomes.

Team-Based Learning Intervention to Improve Obesity Education in Medical School.

Introduction: Obesity is a multifactorial chronic disease and a major contributor to numerous health conditions. Despite the high prevalence, costs, and health effects of obesity, physicians are largely unprepared to treat it. Most medical students and residents lack sufficient training in obesity and obesity management. Methods: We evaluated a two-part team-based learning seminar (TBL) on obesity pathogenesis and treatment for first-year medical students at Case Western Reserve University School of Medicine (CWRU SOM). A questionnaire on attitudes toward obesity and self-perceived knowledge of obesity was administered before and after the TBL, utilizing Likert scales. Results: Of 183 medical students who attended both TBLs, 155 (85%) completed the baseline questionnaire, and 127 (69%) completed the postintervention questionnaire. Confidence in treating obesity increased significantly from preintervention (M = 2.7, SD = 1.0) to postintervention (M = 3.7, SD = 0.8). The attitude that obesity is caused by poor personal choices decreased significantly from preintervention (M = 2.8, SD = 0.9) to postintervention (M = 2.1, SD = 0.9). Self-perceived knowledge of obesity in all nine areas-epidemiology, energy homeostasis, etiologies, nutrition, physical activity, behavior, pharmacology, surgery, and language-increased significantly. Discussion: Despite obesity being one of the most prevalent health concerns, obesity education in medical school is scant. This TBL resulted in improved attitudes toward obesity and self-perceived knowledge of obesity among first-year medical students at CWRU SOM and offers a practical mechanism to introduce more obesity education into undergraduate medical curricula.

Diagnosis and management of post-bariatric surgery hypoglycemia.

INTRODUCTION: While bariatric surgery remains the most effective treatment for obesity that allows substantial weight loss with improvement and possibly remission of obesity-associated comorbidities, some postoperative complications may occur. Managing physicians need to be familiar with the common problems to ensure timely and effective management. Of these complications, postoperative hypoglycemia is an increasingly recognized complication of bariatric surgery that remains underreported and underdiagnosed. AREA COVERED: This article highlights the importance of identifying hypoglycemia in patients with a history of bariatric surgery, reviews pathophysiology and addresses available nutritional, pharmacological and surgical management options. Systemic evaluation including careful history taking, confirmation of hypoglycemia and biochemical assessment is essential to establish accurate diagnosis. Understanding the weight-dependent and weight-independent mechanisms of improved postoperative glycemic control can provide better insight into the causes of the exaggerated responses that lead to postoperative hypoglycemia. EXPERT OPINION: Management of post-operative hypoglycemia can be challenging and requires a multidisciplinary approach. While dietary modification is the mainstay of treatment for most patients, some patients may benefit from pharmacotherapy (e.g. GLP-1 receptor antagonist); Surgery (e.g. reversal of gastric bypass) is reserved for unresponsive severe cases. Additional research is needed to understand the underlying pathophysiology with a primary aim in optimizing diagnostics and treatment options.

Health state utilities associated with hyperphagia: Data for use in cost-utility models.

Objective: Rare genetic diseases of obesity typically present with hyperphagia, a pathologic desire to consume food. Cost-utility models assessing the value of treatments for these rare diseases will require health state utilities representing hyperphagia. This study estimated utilities associated with various hyperphagia severity levels. Methods: Four health state vignettes were developed using published literature and clinician input to represent various severity levels of hyperphagia. Utilities were estimated for these health states in a time trade-off elicitation study in a UK general population sample. Results: In total, 215 participants completed interviews (39.5% male; mean age 39.1 years). Mean (SD) utilities were 0.98 (0.02) for no hyperphagia, 0.91 (0.10) for mild hyperphagia, 0.70 (0.30) for moderate hyperphagia, and 0.22 (0.59) for severe hyperphagia. Mean (SD) disutilities were -0.08 (0.10) for mild, -0.28 (0.30) for moderate, and -0.77 (0.58) for severe hyperphagia. Conclusions: These data show increasing severity of hyperphagia is associated with decreased utility. Utilities associated with severe hyperphagia are similar to those of other health conditions severely impacting quality of life (QoL). These findings highlight that treatments addressing substantial QoL impacts of severe hyperphagia are needed. Utilities estimated here may be useful in cost-utility models of treatments for rare genetic diseases of obesity.

Mapping the Unseen: In Vivo CEST-MRI of Creatine Reveals Improved Cardiac Energetics in Subjects with Obesity Following Bariatric Surgery.

BACKGROUND: Obesity is associated with derangement of cardiac metabolism and the development of subclinical cardiovascular disease. This prospective study examined the impact of bariatric surgery on cardiac function and metabolism. METHODS: Subjects with obesity underwent cardiac magnetic resonance imaging (CMR) at Massachusetts General Hospital before and after bariatric surgery between 2019 and 2021. The imaging protocol included Cine for global cardiac function assessment and creatine chemical exchange saturation transfer (CEST) CMR for myocardial creatine mapping. RESULTS: Thirteen subjects were enrolled, and 6 subjects [mean BMI 40.5 ± 2.6] had completed the second CMR (i.e. post-surgery), with a median follow-up of 10 months. The median age was 46.5 years, 67% were female, and 16.67% had diabetes. Bariatric surgery led to significant weight loss, with achieved mean BMI of 31.0 ± 2.0. Additionally, bariatric surgery resulted in significant reduction in left ventricular (LV) mass, LV mass index, and epicardial adipose tissue (EAT) volume. This was accompanied by slight improvement in LV ejection fraction compared to baseline. Following bariatric surgery, there was a significant increase in creatine CEST contrast. Subjects with obesity had significantly lower CEST contrast compared to subjects with normal BMI (n = 10), but this contrast was normalized after the surgery, and statistically similar to non-obese cohort, indicating an improvement in myocardial energetics. CONCLUSIONS: CEST-CMR has the ability to identify and characterize myocardial metabolism in vivo non-invasively. These results demonstrate that in addition to reducing BMI, bariatric surgery may favorably affect cardiac function and metabolism.

A comprehensive analysis of cytopenias and bone marrow morphology in patients with a history of bariatric and metabolic surgery.

INTRODUCTION: Following bariatric and metabolic surgery (BMS), patients may develop persistent cytopenia(s) despite adequate micronutrient levels. A comprehensive analysis of laboratory and hematopathologic findings in BMS patients with unexplained cytopenia(s) has not been previously described. METHODS: We reviewed the clinical and laboratory data, bone marrow histology, and used ancillary testing to characterize patients with a history of BMS who had subsequent bone marrow biopsies due to unexplained cytopenia(s). RESULTS: All patients had anemia and 59% (23/39) had additional cytopenias. Myelodysplastic syndrome (MDS) and clonal cytopenia of unknown significance (CCUS) were diagnosed in 8% (3/39) and 10% (4/39), respectively. Remaining cases were classified as idiopathic cytopenia of unknown significance (ICUS) with anemia alone (ICUS-A) in 47% (15/32) or multiple cytopenias (ICUS-PAN) in 53% (17/32). Time since surgery, age, or amount of weight loss was not associated with a specific diagnosis. No patient was vitamin B12 or folate deficient. However, vitamin B6 and zinc were decreased in 47% (5/11) and 29% (9/29), respectively. Examination of bone marrow aspirates revealed slight erythroid dyspoiesis affecting <10% of precursors in 60% (9/15) ICUS-A and 59% (10/17) ICUS-PAN. CONCLUSION: Bone marrow findings in patients with unexplained cytopenia(s) after BMS are not specific in the majority of cases, and caution is advised when interpreting dyserythropoiesis. Levels of micronutrients and vitamins other than iron, folate and vitamin B12 are frequently disturbed in this patient cohort and warrant correction and close clinical follow-up.

The use of virtual visits for obesity pharmacotherapy in patients with overweight or obesity compared with in-person encounters.

OBJECTIVE: This study aimed to demonstrate noninferiority using telehealth in treating obesity with phentermine in patients with BMI ≥ 27 kg/m2 with comorbidities or BMI ≥ 30 compared with the standard in-person approach over a 90-day period. METHODS: A 12-week, randomized, prospective, single-center, open label trial compared the use of virtual visits versus in-person visits for the treatment of obesity using phentermine. The primary end point was percentage mean change in body weight from baseline to 12 weeks. A noninferiority approach assuming a 3% noninferiority region was used to assess effect size differences. RESULTS: The weight loss in the virtual visit arm was noninferior to the in-person arm at all time points. At 12 weeks, the mean change in weight was -6.5% among the virtual group and -7.7% among the in-person group. In addition, 65% of virtual patients and 71% of in-person patients demonstrated a weight reduction of at least 5%. There was no difference in medication tolerance, adherence, and compliance. CONCLUSIONS: These results indicate that the virtual obesity pharmacotherapy visits in adults aged 18 to 65 years prescribed phentermine are effective and noninferior in achieving meaningful weight loss after 12 weeks. Future clinical trials are needed to better assess the effectiveness of televisits for obesity pharmacotherapy.

Perioperative management of diabetes in patients undergoing bariatric and metabolic surgery: a narrative review and the Cleveland Clinic practical recommendations.

Bariatric and metabolic surgery is an effective treatment for patients with severe obesity and obesity-related diseases. In patients with type 2 diabetes, it provides marked improvement in glycemic control and even remission of diabetes. In patients with type 1 diabetes, bariatric surgery may offer improvement in insulin sensitivity and other cardiometabolic risk factors, as well as amelioration of the mechanical complications of obesity. Because of these positive outcomes, there are increasing numbers of patients with diabetes who undergo bariatric surgical procedures each year. Prior to surgery, efforts should be made to optimize glycemic control. However, there is no need to delay or withhold bariatric surgery until a specific glycosylated hemoglobin target is reached. Instead, treatment should focus on avoidance of early postoperative hyperglycemia. In general, oral glucose-lowering medications and noninsulin injectables are not favored to control hyperglycemia in the inpatient setting. Hyperglycemia in the hospital is managed with insulin, aiming for perioperative blood glucose concentrations between 80 and 180 mg/dL. Following surgery, substantial changes of the antidiabetic medication regimens are common. Patients should have a clear understanding of the modifications made to their treatment and should be followed closely thereafter. In this review article, we describe practical recommendations for the perioperative management of diabetes in patients with type 2 or type 1 diabetes undergoing bariatric surgery. Specific recommendations are delineated based on the different treatments that are currently available for glycemic control, including oral glucose-lowering medications, noninsulin injectables, and a variety of insulin regimens.

Treating the Chronic Disease of Obesity.

Obesity is a treatable chronic disease. Primary care providers play an essential role in diagnosis, treatment, and comprehensive care of patients with obesity. In recent years, treatment approaches have rapidly evolved, increasing effective and safe therapies. In this review, we provide practical information on the care of patients with obesity with a focus on antiobesity pharmacotherapy within the context of currently available therapeutic modalities such as intensive lifestyle interventions and bariatric surgery.

COVID-19 vaccines are effective in people with obesity: A position statement from The Obesity Society.

The position statement is issued by The Obesity Society in response to published literature, as well as inquiries made to the Society by patients, providers, Society members, policy makers, and others regarding the efficacy of vaccines in persons with obesity against SARS-CoV-2, the virus that causes COVID-19. The Obesity Society has critically evaluated data from published peer-reviewed literature and briefing documents from Emergency Use Authorization applications submitted by Pfizer-BioNTech, Moderna, and Johnson & Johnson. We conclude that these vaccines are highly efficacious, and their efficacy is not significantly different in people with and without obesity, based on scientific evidence available at the time of publication. The Obesity Society believes there is no definitive way to determine which of these three COVID-19 vaccines is "best" for any weight subpopulation (because of differences in the trial design and outcome measures in the phase 3 trials, elapsed time between doses, and regional differences in the presence of SARS-CoV-2 variants [e.g., South Africa B.1.351 in Johnson & Johnson trial]). All three trials have demonstrated high efficacy against COVID-19-associated hospitalization and death. Therefore, The Obesity Society encourages adults with obesity ≥18 years (≥16 years for Pfizer-BioNTech) to undergo vaccination with any one of the currently available vaccines authorized for emergency use by the US Food and Drug Administration as soon as they are able.

Association of prior metabolic and bariatric surgery with severity of coronavirus disease 2019 (COVID-19) in patients with obesity.

BACKGROUND: Obesity is a risk factor for poor clinical outcomes in patients with coronavirus disease 2019 (COVID-19). OBJECTIVES: To investigate the relationship between prior metabolic surgery and the severity of COVID-19 in patients with severe obesity. SETTING: Cleveland Clinic Health System in the United States. METHODS: Among 4365 patients who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between March 8, 2020 and July 22, 2020 in the Cleveland Clinic Health System, 33 patients were identified who had a prior history of metabolic surgery. The surgical patients were propensity matched 1:10 to nonsurgical patients to assemble a cohort of control patients (n = 330) with a body mass index (BMI) ≥ 40 kg/m2 at the time of SARS-CoV-2 testing. The primary endpoint was the rate of hospital admission. The exploratory endpoints included admission to the intensive care unit (ICU), need for mechanical ventilation and dialysis during index hospitalization, and mortality. After propensity score matching, outcomes were compared in univariate and multivariate regression models. RESULTS: The average BMI of the surgical group was 49.1 ± 8.8 kg/m2 before metabolic surgery and was down to 37.2 ± 7.1 at the time of SARS-CoV-2 testing, compared with the control group's BMI of 46.7 ± 6.4 kg/m2. In the univariate analysis, 6 (18.2%) patients in the metabolic surgery group and 139 (42.1%) patients in the control group were admitted to the hospital (P = .013). In the multivariate analysis, a prior history of metabolic surgery was associated with a lower hospital admission rate compared with control patients with obesity (odds ratio, 0.31; 95% confidence interval, 0.11-0.88; P = .028). While none of the 4 exploratory outcomes occurred in the metabolic surgery group, 43 (13.0%) patients in the control group required ICU admission (P = .021), 22 (6.7%) required mechanical ventilation, 5 (1.5%) required dialysis, and 8 (2.4%) patients died. CONCLUSION: Prior metabolic surgery with subsequent weight loss and improvement of metabolic abnormalities was associated with lower rates of hospital and ICU admission in patients with obesity who became infected with SARS-CoV-2. Confirmation of these findings will require larger studies.

Fruit and vegetable pricing by demographic factors in the Birmingham, Alabama, metropolitan area, 2004-2005.

INTRODUCTION: Fruit and vegetable cost may influence consumption. Because the contextual environment influences food outlet type and availability, we wanted to determine whether neighborhood demographics were associated with prices of fruits and vegetables. METHODS: We surveyed 44 grocery stores in the Birmingham, Alabama, metropolitan area to determine prices of 20 fruits and vegetables. Stores were geocoded and linked to the corresponding Census 2000 block group to obtain data for the independent variables - percentage African American, percentage with at least a high school diploma, and percentage of households below the poverty level. We conducted multiple linear regressions to estimate these predictors for each fruit and vegetable's mean price per serving during 2 seasons (fall/winter 2004, spring/summer 2005). RESULTS: In the fall, we found no significant relationships between the predictors and prices of any fruits and vegetables in the survey. In the spring, the percentage who had at least a high school diploma was a predictor of price per serving for potatoes (beta = 0.001, P = .046). CONCLUSION: Neighborhood demographics have little consistent influence on fruit and vegetable prices in Birmingham, Alabama, which may be a function of grocery store density, transportation patterns, and shopping patterns. The regional setting of the food environment has implications for food availability, variety, and price.