Nutritional Care Process in Hospitalized Patients with Obesity-Related Multimorbidity

Abstract

Obesity-Related Multimorbidity (ORM) is understood as the group of secondary diseases caused by metabolic alterations that arise from obesity. Nowadays there is a growing incidence of people with ORM who seek health services. Since this condition substantially impacts nutritional status and therefore in the survival prognosis during the hospital stay, ORM represents a challenge for health professionals. This forces doctors to specify nutritional recommendations according to clinical characteristics in individuals with obesity and types of comorbidities. Therefore, the objective of this narrative review is to present the current evidence-based recommendations that support the hospital nutritional care process for individuals with ORM. It concludes that nutritional treatment is complex and gaps in the research regarding this population group still exist. Because there are no specific guidelines for nutritional screening tools, calculating total energy requirements (alternatives to indirect calorimetry), determining fluid, protein, and immunonutrient requirements, the use of parenteral nutrition in ORM with kidney, liver, and heart failure and sarcopenic obesity that should be addressed in the new literature. For now, the standard practice in these cases is to prioritize the problem to be treated according to the maximum clinical benefit. Despite this, it is established that the nutritional care process must be systematic to be clear and objective. This document is addressed to all healthcare professionals who make up the multidisciplinary nutritional support team.

1. Introduction

Obesity-Related Multimorbidity (ORM) shows high prevalence and is identified as a serious public health problem [1] due to its effects on mental health, long-term loss of functionality, increased morbidity and mortality, economic losses, and decreased quality of life [2,3].

Due to the complexity of ORM, a standardized model is required to guide the multidisciplinary nutritional support team during clinical practice. The Nutrition Care Process (NCP) proposed by the Academy of Nutrition and Dietetics (AND) is validated for hospital use and is the basis for the structure of this narrative review [4,5].

ORM is understood as the group of secondary diseases caused by metabolic alterations that arise from obesity, which are considered non-infectious, non-communicable, and are marked by slow and long-lasting progression in which the function or structure of the affected tissues or organs deteriorates over time. ORM includes among the most common the following group of conditions: metabolic syndrome, Type 2 diabetes (T2D), cardiovascular disease (CVD), peripheral vascular disease (PVD), systemic arterial hypertension (SAH), and metabolic dysfunction-associated steatotic liver disease (MASLD) [6] These diseases are the result of a combination of genetic, physiological, environmental, and behavioral factors. The pathophysiological mechanisms are related to the production of free radicals, oxidative stress, low-grade chronic inflammation, autoimmunity, and apoptosis [7,8]. During hospitalization, the low-grade chronic inflammation that characterizes obesity may worsen and promote the development of more severe infectious or metabolic complications that require the use of additional medications, impacting nutritional status and survival prognosis [9,10,11]. Medical treatment, along with the proper and timely management of malnutrition in hospitalized patients with ORM, significantly improves health outcomes, reduces the length of hospital stays, the number of admissions to the Intensive Care Unit (ICU), hospital readmissions, home care, and the consumption of social and technological resources [10]. This narrative review is addressed to all healthcare professionals who make up the multidisciplinary nutritional support team, and the objective is to describe the current evidence-based recommendations that support the hospital nutritional care process established for individuals living with obesity and multimorbidity.

The guidelines used in this narrative review followed the Scottish Intercollegiate Guidelines Network (SIGN). These were classified into four categories: A, B, 0, and good practice points or expert consensus (GPP). Level A and B recommendations are based on solid evidence derived from biochemistry and physiology that have been applied to clinical settings. Recommendations based on existing Recommended Dietary Allowances (RDA) receive a level A classification. In contrast, recommendations based on Dietary Reference Intakes (DRIs) are assigned a level B classification. Many are supported by limited evidence, but they underwent a consensus process that resulted in a percentage of agreement (%). Qualification as a “Strong” consensus required >90% of votes. “Consensus” required between >75–90% of votes. A “Majority” agreement won >50–75% of votes. When the agreement was below 50% of the votes, there was no consensus [12,13].

2. Hospital Factors That Alter Nutritional Status in Patients with Obesity-Related Multimorbidity (ORM)

One of the most used nutritional strategies in managing individuals with ORM in community settings is the creation of an energy deficit ranging from 500 to 750 kcal/day to promote efficient and safe weight loss of approximately 0.5 to 1 kg per week [14]. However, admission to a hospital unit exposes individuals to a series of factors that lead to involuntary and excessive weight loss, which may contribute to the development of various forms of malnutrition. The use of hypocaloric diets is compounded by circumstances such as unappetizing food, prolonged fasting due to medical instructions, administrative procedures, pharmacological treatments, gastrointestinal surgeries, and the placement of drains or dialysis. All of these may cause alterations in nutrient absorption and/or metabolism, disturbances in fluid and electrolyte balance, and gastrointestinal symptoms such as decreased appetite, diarrhea, constipation, abdominal distension, early satiety, anorexia, dysgeusia, dysphagia, and mucositis, among others. In this way, the hospital environment fosters nutritional deficiencies and energy deficits that exceed current recommendations for individuals with ORM [15,16].

Additionally, patients with ORM in critical condition or with a metabolic response to injury may present hypermetabolic states. In protein metabolism, proteolysis occurs, leading to significant losses of muscle mass—up to 2% of skeletal muscle per day in the ICU [17]—and loss of bone mass, which are associated with metabolic acidosis, sarcopenia, osteoporosis, frailty, fatigue, disability, and mortality [18,19]. The excessive release of pro-inflammatory cytokines and cortisol leads to alterations in carbohydrate (CHO) metabolism due to the development of peripheral insulin resistance, resulting in hyperglycemia that increases the infection rate and delays wound healing [20,21]. Regarding lipid metabolism, there is a decrease in lipoprotein lipase (LPL) activity—an enzyme that hydrolyzes triglycerides and breaks them down into free fatty acids and glycerol, releasing them into muscle and adipose tissue to later provide energy via beta-oxidation—potentially causing dyslipidemias, primarily hypoalphalipoproteinemia (low levels of high-density lipoprotein cholesterol [HDL]) and hypertriglyceridemia [20,22].

As for micronutrient metabolism, deficiencies may occur due to increased requirements for vitamins and minerals, leading to profound depression of the immune system, increased risk of infections, and immunomodulation failure that perpetuates inflammation. Likewise, alterations in the antioxidant system, fluid and electrolyte balance, and acid-base equilibrium may also be present [21]. In addition, there may be altered drug assimilation, as sarcopenic obesity—commonly observed in patients with ORM and prolonged immobility—can reduce drug transport and pharmacokinetics, resulting in decreased pharmacotherapeutic success [20]. Furthermore, changes in the richness and diversity of the gut microbiota (GM) (dysbiosis) may affect the oro-gastrointestinal, respiratory, and genitourinary mucosae, leading to neuro-immuno-endocrine-metabolic alterations [23,24,25,26].

Finally, the decline in cognition and increased prevalence of depression during hospitalization contribute in part to nutritional and psychosocial impairment. In older adults with multimorbidity, abdominal obesity and malnutrition have been shown to be factors associated with lower overall and specific cognitive performance and an increase in depressive symptoms [27]. Therefore, combining psychological approaches that include conscious eating can contribute to improving the feeling of well-being [28].

3. Nutritional Intervention in Hospitalized Adults with Obesity-Related Multimorbidity

The NCP has been recognized as a standardized method for developing new personalized strategies in the hospitalized population. The preliminary step to initiating the NCP is nutritional screening, a tool that enables the identification of individuals at risk of or currently experiencing malnutrition. Nutritional screening should be conducted within the first 48 h of hospital admission and must be validated for the target population. For individuals with ORM, the following screening and assessment tools are available: the Malnutrition Universal Screening Tool (MUST), the Nutritional Risk Screening (NRS), and Royal Free Hospital–Nutritional Prioritizing Tool (RFH–NPT) [18]. With these tools, we obtain a classification of the risk of developing malnutrition, and in all patients with moderate or high risk, a complete nutritional evaluation should be performed. Additional tools for assessing and diagnosing malnutrition include the Modified Nutrition Risk in Critically Ill (mNUTRIC) tool [20]. However, every critically ill patient staying for more than 48 h in the ICU should be considered at risk for malnutrition [19].

4. Nutritional Status Assessment

The complete nutritional assessment includes the search for anthropometric, biochemical, clinical, dietary and lifestyle indicators to establish a nutritional diagnosis according to the Global Leadership Initiative on Malnutrition (GLIM) criteria [29,30]. These tools typically include anthropometric indicators such as weight loss, Body Mass Index (BMI), and muscle mass (quantity or function). They also consider dietary indicators such as changes in food intake and clinical indicators such as the presence of conditions associated with food malabsorption or diseases with an acute inflammatory response. Individuals with ORM who are classified as at risk or malnourished must undergo a comprehensive nutritional assessment to define the most appropriate nutritional support strategy [10,31].

4.1. Anthropometric Measurements

Anthropometric parameters include the following measurements: height, current weight, calf, arm, and abdominal circumferences. Current weight is unreliable in ORM, as it tends to overestimate energy expenditure. Weight measurement is unrealistic in the hospital environment, and weight estimation formulas tend to overestimate it since they require measuring circumferences, including the abdominal circumference, in patients lying on their back or supine, which makes the measurement inaccurate. Therefore, during hospitalization, it is recommended to use the “reference body weight” or “ideal body weight” (IBW) for individuals with obesity”, which is calculated using the formula: [(height in meters)² × 25]. Recently, it has been reported that only one-third of excess body weight in individuals with obesity is metabolically active. For this reason, the use of “adjusted body weight” (ABW) is recommended, which is calculated with the following formula: [(current weight − reference body weight) × 0.33 + reference body weight] [18,19]. Estimating BMI as the sole tool for defining and classifying obesity in hospitalized patients is imprecise due to the presence of edema and body positions that interfere with accurate measurements, among other factors. Ideally, BMI should be interpreted alongside other validated indicators of excess fat, such as waist circumference, waist-to-height ratio, or waist-to-hip ratio, or by using body composition methods that determine total body fat percentage or visceral fat. These parameters in patients with ORM contribute to the definition of “clinical obesity,” which was recently proposed by The Lancet Commission [32].

Validated methods for assessing body composition in hospitalized patients include: Dual-energy X-ray Absorptiometry (DEXA), Computed Axial Tomography (CAT), and Magnetic Resonance Imaging (MRI). Multi-frequency Bioelectrical Impedance Analysis (mfBIA) is not recommended for individuals with fluid and electrolyte imbalances or those receiving intravenous solutions, as these reduce the reliability of mfBIA [33,34]. However, phase angle estimation using mfBIA—related to cell membrane integrity—is useful as a survival prognostic marker (greater than 5.1°) and as an indicator of muscle mass preservation (greater than 4.8°). Nevertheless, the lack of availability of this equipment, limited patient mobility, and weight exceeding the usage limits of these devices in hospital settings make their application limited. Thus, waist circumference is one of the most accessible methods for clinical practice in hospitals and should be measured in individuals with a BMI greater than 25 kg/m² when insulin resistance or MASLD is suspected. In Mexico, the validated cut-off points as indicators of central obesity are waist circumference greater than or equal to 84 cm in women and greater than or equal to 98 cm in men, or a waist-to-height ratio greater than 0.5 [35].

4.2. Biochemical Data

Biochemical indicators consist of different types of biomarkers: metabolic biomarkers, such as glucose, glycated hemoglobin, insulin, liver function tests, and lipid profile; inflammatory biomarkers, such as complete blood count, serum proteins, C-reactive protein, HDL cholesterol; protein metabolism and renal function biomarkers such as Blood Urea Nitrogen (BUN), urea, serum creatinine, uric acid, and Urine Urea Nitrogen (UUN) from 24-h urine collection to calculate Nitrogen Balance ([NB = (grams of protein consumed in a day/6.25) − (UUN/0.85 + 4)]. When BN is greater than +2 it means there is protein anabolism, when it is between −2 to +2 it means there is a balance between protein intake/administration and catabolism, and when BN is less than −2 it means there is increased protein catabolism, which will require increased protein administration. It is important to note that BN calculation is only useful in patients without kidney failure [36]. Additionally, biomarkers of acid–base and fluid–electrolyte balance are used, as well as those for diagnosing Refeeding Syndrome (RS), such as blood nitrogen compounds, serum electrolytes (primarily phosphorus, sodium, potassium, and calcium), serum thiamine, and arterial blood gas analysis [37,38].

4.3. Clinical Examination Findings

Clinical indicators include vital signs, gastrointestinal symptoms and swallowing disorders, drug-nutrient interactions, urine output, fluid balance, bowel movements, and insensible losses of fluids and/or nutrients, such as gastrointestinal drainage from tubes or enterocutaneous fistulas. It is important to consider the use of handgrip dynamometry and functional performance tests in individuals who are physically able to undergo them [16], as well as the evaluation of signs of nutrient deficiencies or excesses, loss of muscle mass and fat stores, fluid retention, and functional capacity through the Nutrition-Focused Physical Exam (NFPE) [39].

4.4. Dietary Parameters

Fasting days and food intake prior to hospitalization should be assessed using a usual diet questionnaire or a 24-h dietary recall, with the aim of evaluating the risk of RS. To determine whether nutritional requirements are efficiently met, it is necessary to assess the patient’s daily energy and nutrient intake or administration. This can be done using objective methods, such as weighing the food before and after each meal, or semi-quantitative methods. Such as recording consumption from the hospital diet tray—for example, whether the patient consumed none, half, a quarter, or all the food on the plate. Subsequently, the percentage of intake relative to the requirement should be calculated ([calories or nutrient consumed/calories or nutrient required] × 100), where intake percentages below 90% represent suboptimal nutrition and those above 110% indicate excessive intake [40,41,42]. This section also includes the evaluation of the availability and functionality of oral, enteral, or parenteral access routes [43,44].

4.5. Lifestyle

Lifestyle indicators provide a nutritional overview prior to hospital admission and include behaviors, skills, attitudes, and eating habits, as well as physical activity, sleep, and substance use habits [37,39].

5. Nutritional Diagnosis

A comprehensive evaluation of these indicators will allow for the definition of nutritional diagnoses, which are generally documented using a format known as “PES”, an acronym where “P” stands for the nutritional Problem, “E” for the Etiology, and “S” for the Signs or symptoms supporting the presence of the nutritional problem. The diagnosis enables the establishment of an integrated and personalized nutritional treatment plan, as well as the determination of the monitoring frequency and indicators to be tracked during the hospital stay [5,45,46]. The most common structured examples of nutritional diagnoses in PES format for this population are shown in

Table 1. Most common nutritional diagnoses in the population with Obesity-Related Multimorbidity.

Nutritional Problem (P)		Etiology (E)		Signs or Symptoms (S)
Increased energy expenditure. Deficient or excessive infusion of enteral or parenteral nutrition. Altered nutrition-related laboratory values. Increased nutrient needs (immunonutrients).	related to	Chronic-acute inflammation. Multimorbidity. Inadequate calculation of requirements due to obtaining weight. Malnutrition. Drug-nutrient interaction. Hypermetabolism.	as evidenced by	Weight loss. Increase in basal metabolic rate. Energy consumption percentage is less than 90% and greater than 110% per day. Alteration in blood of liver enzymes, pancreatic enzymes, lipids, proteins, electrolytes, glucose, nitrogen elements, vitamins, minerals, CO2 and pH. Clinical signs of specific nutrient deficiencies.
Inadequate protein, energy and fiber intake. Gastrointestinal function alteration.		Reduced appetite. Gastrointestinal symptoms. Inability or intolerance to oral or enteral feeding. Side effects of medical interventions or treatments.		Less than 90% of daily protein, energy, and fiber intake. Constipation, diarrhea, nausea, vomiting, abdominal bloating and/or slow gastric emptying.

Adapted from: [5].

.

6. Estimation of Nutritional Requirements

The determination of Total Energy Expenditure (TEE) should be obtained through indirect calorimetry (IC), which is considered the “gold standard” [15,18,19]. However, if IC is not available, TEE may be determined using validated predictive equations selected based on the patient’s specific condition and/or type of disease associated with ORM (Table 2). To determine protein requirements, the following factors must be considered: quality and quantity of preexisting muscle mass, acid–base status, protein losses due to proteinuria, drainage, dialysis, diarrhea, and/or vomiting, and the degree of metabolic stress. Calculating protein requirements using NB may overestimate protein intake in ORM patients who experience nitrogen retention in conditions such as the acute phase of the metabolic response to injury in critically ill patients, renal injury, or liver disease [15,19]. Protein requirements must be individualized and established for each stage of illness or clinical condition and therapeutic goals, particularly in obesity (Table 2). Moreover, recent studies highlight the need to individualize protein dosing in critically ill patients with obesity. An analysis from the effect of higher protein dosing in critically ill patients with high nutritional risk (EFFORT Protein) study showed that the group with a BMI of 30 to 39.9 kg/m² that received high protein doses (>2.2 g per kg of ABW per day) tended to have lower mortality compared to the group that received low doses (0.8 to 1.2 g/kg/day) [47,48]. However, high protein doses tended to increase the number of days on ventilatory support and mortality in the group with BMI >40 kg/m² compared to the group that received low doses. Therefore, protein doses >2.5 g/kg of IBW/day currently recommended in clinical practice guidelines may be excessive in patients with class III obesity and highlight the need for further research stratified by obesity class to strengthen current guidelines [48].

Fluid intake depends on the chosen feeding route. Oral fluid intake is recommended at 1 mL per kcal; for bariatric surgery, a minimum of 1500 mL is recommended (Grade GPP) [49]. For enteral or parenteral administration, the recommended dose is body surface area (BSA) = (ideal weight × 4) + 7/(weight + 90) per day. Without edema: 1.2 to 1.5 L × BSA or 30 to 40 mL/kg/day. With edema or ascites: 0.8 to 1.2 × BSA or 20 mL/kg/day [16,31].

7. Medical Nutrition Therapy Recommendations

Hospitalized individuals with ORM require therapeutic diets with lower carbohydrate content and higher protein content due to insulin resistance and increased protein requirements that are commonly observed. Therefore, it is recommended that total caloric intake be distributed as follows: less than or equal to 45% carbohydrates, 20% protein (or 1.2 g/kg/day), and greater than or equal to 35% fat of the TEE [31,37]. Therapeutic diets are designed to be adapted to conditions or diseases that require texture control, nutrient adjustments, or a special dietary regimen.

Therapeutic diets are classified as follows [50]:

• By consistency modification: clear liquids, full liquids, semi-liquid, blended, puréed, soft, finely chopped, and bland.
• By energy content: hypercaloric, isocaloric, and hypocaloric.
• By nutrient modification: modified in CHO, high-protein or low-protein, low-fat, lactose-free, high or low in fiber, dry, high or low in sodium, potassium, calcium, iron, vitamin K, etc.

In addition, depending on the hospital, there may be standardized diets for specific metabolic diseases such as T2D, SAH, CVD, or other chronic metabolic diseases. The type of hospital diet prescribed for each disease should be individualized according to biochemical and metabolic alterations, oro-esophageal-gastrointestinal symptoms, allergies, cultural, religious, or social preferences, food aversions, and possible drug-nutrient interactions [41].

In hospital settings, hypocaloric diets (500 kcal/day deficit) should be reserved only for temporary use in individuals with ORM combined with poor metabolic control, those at risk of developing RS, and in rehabilitation units for obesity [16]. The hospital food service should offer the 3 major meals and, whenever possible, two to three snacks to promote glycemic control and meet the individual’s nutritional requirements [50]. Healthy eating patterns are strongly supported by evidence as strategies that contribute to the control of ORM (

Table 2. Estimation of Energy and Macronutrients Requirements in Hospitalized Adults with Obesity-Related Multimorbidity (ORM).

Clinical Condition	Energy	Protein	CHO	Lipids	References
Obesity	ORM with metabolic dysregulation: Hypo-energetic diet in 20–25 kcal/kg of ABW/day (Recommendation). Avoid the prescription of a hypo-energetic diet for patients with acute conditions that do not lead to a metabolic response or surgical procedure, and sarcopenic obese elderly (Grade: GPP, consensus). Elderly patients: 27–30 kcal/kg of ABW/day (Grade GPP, Strong consensus).	1.2–1.5 g/kg of ABW/day (Grade A, Strong consensus). or 1–1.1 g/kg of ABW/day (Recommendation) Impaired Kidney Function (eGFR <30 mL/min/1.73 m2): 0.8 g/kg of ABW/day (Grade B, Strong consensus).	45% of TEE (Grade GPP, Majority agreement).	20% of TEE (Grade GPP, Majority agreement).	[13,16,37]
T2D		20% of TEE (Grade GPP, Strong consensus). 1–1.5 g/kg of ABW/day (Grade 0, Strong consensus).	<45% of TEE Avoided <40% of TEE in malnutrition (Grade GPP, Strong consensus).	30–35% of TEE (Grade 0, Strong consensus). and Cardioprotective pattern. Saturated fatty acids: <7% of TEE. Monounsaturated fatty acids: 20% of TEE. Polyunsaturated fatty acids: 10% of TEE. Trans fatty acids: <1% of TEE. Cholesterol: <200 mg/day (Grade B, Strong consensus).	[16,51]
Cardiovascular disease: SAH, AMI, and Stroke		15–20% of TEE (Grade GPP, Strong consensus).	45–60% of TEE (Grade GPP, Strong consensus).		[16,52,53]
MASLD		1.2–1.5 g/kg of ABW/day (Grade GPP, strong consensus). and Low in aromatic amino acids (No consensus).	Glucose oxidation rate: ≤5 mg/kg/min. (Grade GPP, Strong consensus).	Mediterranean diet: 30–35% of TEE (Grade 0, Strong consensus). Omega-3 supplementation: 3–4 g/day (Grade GPP, Strong consensus).	[18,54,55]
Obesity Post-bariatric Surgery	First 3 months of PO: 800 kcal/day 3 months to 1 year of PO: Do not exceed (Men: 1500 kcal/day and Women: 1200 kcal/day). 1 year of PO: 16 kcal/kg of ABW/day (Grade GPP, Strong consensus)	10–35% of TEE First 3 months of PO, at least: Men: 56 g/day and Women: 46 g/day. 3 months to 1 year of PO: 0.8–1.2 g/kg IBW/day >1 year of PO: 1.1–1.2 g/kg IBW/day (Grade GPP, Strong consensus)	50–130 g/day 0% added sugar (Grade GPP, Strong consensus).	20–35% of TEE Monounsaturated fatty acids: 20% of TEE Saturated fatty acids: <10% of TEE (Grade GPP, Strong consensus).	[14,16,19,49]
Obesity in ICU	ESPEN Acute phase (First 3–7 days of ICU stay): <70% of TEE (Grade A, strong consensus). BMI > 30 kg/m2: 20–25 kcal/kg of ABW/day (Grade 0, Consensus). ASPEN Acute phase (First 7–10 days of ICU stay): 12–25 kcal/kg IBW/day (Grade Moderate, weak). BMI 30–35 kg/m2: 11–14 kcal/kg ABW/day (Expert consensus). BMI > 50 kg/m2: 22–25 kcal/kg IBW/day (Expert consensus). Over 60 years old: Penn State University: TEE = (REE with Mifflin × 0.96) + (Tmax × 167) + (Vmin × 31) − 6212 (Recommendation).	ESPEN 1.3 g/kg of ABW/day (Grade GPP, Consensus). ASPEN Acute phase: 0.8–1.2 g/kg IBW/day (Recommendation). BMI 30–39.9 kg/m2: ≥2.0 g/kg IBW/day (Expert consensus).	At least 130 g/day Glucose oxidation rate: <5 mg/kg/min (Grade GPP, Strong consensus).	Dose: <1.5 g/kg of ABW/day (Grade 0, Strong consensus). Type of mixed oil in Respiratory Distress Syndrome, Acute Lung Injury, and Sepsis: LCT + MCT and omega-3 (Grade 0, Strong consensus).	[15,18,19,20]

Abbreviations: ABW: Adjusted body weight; AMI: Acute Myocardial Infarction; ASPEN: American Society for Parenteral and Enteral Nutrition; CHO: carbohydrates; eGFR: Estimated Glomerular Filtration Rate, ESPEN: European Society for Clinical Nutrition and Metabolism, GPP: Good practice points or expert consensus, IBW: Ideal Body weight, ICU: Intensive care unit; MASLD: Metabolic Dysfunction-Associated Steatotic Liver Disease; PO: Post-operative; REE: Resting energy expenditure; SAH: systemic arterial hypertension, T2D: Type 2 Diabetes; TEE: Total Energy Expenditure; Tmax: maximum temperature in degrees Celsius; Vmin: minute volume of the respirator.

and

Table 3. Estimation of Fiber and Micronutrients Requirements and Therapeutic Diet in Hospitalized Adults with Obesity-Related Multimorbidity.

Clinical Condition	Fiber	Micronutrients	Therapeutic Diet	References
Obesity	25–35 g/day Older patients: 30 g/day (Grade 0, Strong consensus).	DRIs. Vitamin D: 4000–5000 IU/day (100–125 mg/day) should be administered for 2 months in patients with recurrent deficiency (Grade B, Strong consensus).	Isocaloric in acute care (Grade B, Strong consensus). Hypocaloric diets could improve metabolic outcomes in patients with severe insulin resistance, and in rehabilitation units for obesity (Grade 0, Strong consensus). Behavioral lifestyle changes in relation to the type of obesity phenotype (Grade B, Strong consensus). Cardioprotective pattern controlled in CHO: Mediterranean, DASH, vegetarian or vegan style diet (Grade A, Strong consensus). Cardioprotective pattern features: (1) Decrease salt intake (<6 g/day). In arterial hypertension or acute decompensated heart Failure at least 2.8 g (Grade B, Strong consensus). (2) Eat two portions of oily fisheach week. (3) Choose whole grains instead of refined grain. (4) Eat vegetables every day at least 300 g, fruit and berries at least 200 g. (5) Eat nuts and legumes 3 times per week. (6) Consume less red and processed meat, refined CHO, and sugar-sweetened beverages. (7) Replace saturated fats with unsaturated fats (Grade GPP, Strong consensus). T2D–Quantify CHO (Grade A, Strong consensus). Low-carbohydrate enteral formulas in patients with severe insulin resistance (Grade GPP, No Consensus). EN in MASLD: standard formulas, soy-free, with branched-chain amino acids (Recommendation, no consensus). PN in MASLD: omega-3, long-chain triglycerides with minimal soy content (Grade 0, Strong consensus).	[12,13,16,18,50]
T2D	20–40 g/day (Grade 0, Strong consensus).	DRIs. Vitamin C. 200–500 mg/day in patients with chronic oxidative stress (T2D, smoking, heart failure, alcoholism, COPD, and dialysis) or malabsorption (Grade GPP, Strong Consensus). Chromium: 200 –250 µg/day for 2 weeks for patients with PN who are suspected to be deficient due to insulin resistance (Grade 0, Strong consensus).		[12,16,18,28,50]
Cardiovascular disease: SAH, AMI, and Stroke		DRIs. Sodium: 1–3 g/day; <200 mg/day (in uncontrolled SAH or renal failure) Potassium: 2000–3700 mg/day. Calcium: 800–1500 mg/day. Magnesium: 240–1000 mg/day Vitamin C: 200–500 mg/day in patients with chronic oxidative stress (diabetes mellitus, smoking, heart failure, alcoholism, severe COPD, and chronic dialysis or malabsorption (Grade GPP, Strong consensus).		[12,16,18,50,56]
MASLD	25–35 g/day (Grade 0, Strong consensus).	DRIs. Sodium: 2 g/day (in ascites, edema) Calcium: 800–1200 mg/day. B1: 100 mg/day D3: At least 3000 IU/day. Vitamin E: 800 IU/day Choline: 400–550 mg/day (Grade 0, Strong consensus).		[12,18,50,55,57]
Obesity Post-bariatric Surgery	First 3 months of Post: Low fiber diet (Grade GPP, Strong consensus).	B12: 350–1000 μg/day. Iron: 45–60 mg/day Folic acid: 400–1000 μg/day (Grade A, Strong consensus). D3: 3000–6000 IU/day (Grade B, Strong consensus). Calcium: 1200–1500 mg/day. B1: ≥12 mg/day. Zinc: 8–22 mg/day (Grade 0, Strong consensus). Cooper: 1–2 mg/day. Vitamin A: 5000 UI/day. Vitamin E: 15 mg/day. Vitamin K: 90–120 μg/day (Grade GPP, Strong consensus).	Interventions should first include dietary change (Grade B, Strong consensus) First 2 days: Clear liquids Days 10 to 14: Full liquids After 14 days: Mechanically and chemically soft After 3 months: Hypocaloric diet (Grade GPP, Strong consensus)	[12,14,16,49,50]
Obesity in ICU	Acute phase: Do not use fiber (Grade 0, Strong consensus). Recovery phase: 10–20 g/day (Grade GPP, Consensus).	DRIs in EN or PN. B1: 100–300 mg/day IV from admission for 3–4 days (Grade B, Consensus). Vitamin C: 2–3 g/day IV repletion dose, during the acute phase of inflammation (Grade B, Consensus). Measure 25(OH) D in all patients considered at risk (Grade GPP, Strong consensus). Chromium: Insulin resistant patients, 3–20 μg/hour IV for 10 h and up to 4 days, may be required (Grade 0, Strong consensus).	EN or PN Provide less than 70% of requirements during the first week of ICU stay (Grade B, strong consensus).	[18,19]

Abbreviations: AMI: Acute Myocardial Infarction; B₁: thiamine vitamin; B₁₂: cyanocobalamin vitamin; CHO: carbohydrates; COPD: Chronic obstructive pulmonary disease; D₃ or 25(OH)D: 25-hydroxyvitamin D or cholecalciferol; DASH: Dietary Approaches to Stop Hypertension; DRIs: Dietary Reference Intakes; EN: Enteral nutrition; GPP: Good practice points or expert consensus; ICU: Intensive care unit; ICU: Intensive care unit; IV: intravenous, kg: kilogram; MASLD: Metabolic Dysfunction-Associated Steatotic Liver Disease; PN: Parenteral Nutrition; Post: Post-operative; T2D: Type 2 Diabetes; UI: International units.

).

We know that many patients with obesity have difficult metabolic control, and the cause of hunger–satiety is diverse. In these cases, the existence of 4 obesity phenotypes offers us the following strategies [28,58]:

7.1. Phenotype 1 “Hungry Brain”

“Hungry brain” is characterized by alterations in satiety due to a disruption of the gut–brain axis. It is recommended to feed high-protein, high-fiber, and high-volume foods to induce greater satiety. Upon discharge from the hospital, encourage physical activity that releases endorphins and increases well-being.

7.2. Phenotype 2 “Emotional Hunger”

“Emotional hunger” or hedonic eating is characterized by preferring to consume foods for their palatability rather than their nutritional value, which leads to overeating calories. This is due in part to the altered increase in the activity of dopamine-releasing neurons in the ventral tegmental area (VTA) in the brain. It is recommended that foods with a low glycemic index be provided to reduce insulin’s antilipolytic and lipogenic action. Upon discharge from the hospital, it encourages physical activity that increases motivation, mental health, and self-efficacy and reduces stress and anxiety.

7.3. Phenotype 3 “Hungry Gut”

“Hungry gut” is characterized by an abnormal duration of satiety due to rapid gastric emptying. It is recommended to provide foods high in soluble fiber to normalize bowel movements and improve GM dysbiosis. Upon discharge from the hospital, encourage physical activity that strengthens the abdominal muscles to regulate bowel movements.

7.4. Phenotype 4 “Slow Burning”

“Slow burning” is characterized by decreased energy metabolism. Knowing the obesity phenotype each patient presents can improve the self-efficacy of nutritional therapy, as it allows for more personalized and targeted therapy. Feeding foods rich in omega-3 fatty acids and antioxidants is recommended. Upon discharge from the hospital, physical activity should be performed to increase musculoskeletal mass to boost fat metabolism as an energy source.

8. Oral Nutritional Supplements

Oral Nutrition Support (ONS) provides nutrients in liquid or powder form and is indicated as an oral supplement when intake from the hospital diet covers less than 80% of the patient’s requirements. The most used ONS in patients with ORM are [13,59,60]:

• Specialized polymeric formulas: Most frequently used are high-protein (Grade B strong consensus) [13] or modified in carbohydrate content, containing sources such as maltodextrins, monounsaturated fatty acids, omega-3 fatty acids, and soluble fiber to promote glycemic control.
• Formulas containing immunonutrients: Recommended for specific conditions such as systemic inflammation, perioperative support, trauma, burns, or gastrointestinal surgery.
• Oligomeric and elemental formulas: Indicated for conditions involving intestinal malabsorption.
• Fiber or protein modules: Used when the requirement for these nutrients is elevated in patients with ORM.

9. Recommendations on the Use of Enteral Nutrition

Enteral Nutrition (EN) is defined as the set of procedures used to deliver food to the gastrointestinal tract via a feeding tube. The most common indications for EN in hospitalized patients with ORM are established when [61]:

• The oral route fails to meet more than 60% of daily energy needs for 3 to 7 days.
• PO cannot or should not be used (due to invasive mechanical ventilation, sedation, coma, oral/esophageal/laryngeal/maxillofacial injury, obstruction, or surgery, etc.).
• Severe dysphagia contraindicates oral route. In individuals with severe malnutrition or in the ICU, EN should be initiated within the first 24 to 48 h of admission with trophic feeding providing 10 to 15 mL/hour or 500 kcal per day.

In conditions such as active gastrointestinal bleeding, shock, and low tissue perfusion with high doses of vasopressors or inotropes (greater than 0.3 μg/kg/min) or severe metabolic acidosis, it is recommended to delay initiation and start EN once hemodynamic stability is achieved or the acid–base imbalance is corrected [18].

The required duration of EN will determine the type of tube to be used: for less than one month, temporary tubes such as nasogastric or nasoenteric tubes are recommended. Permanent tubes, such as gastrostomy or jejunostomy, are indicated when EN is needed for longer than one month. In cases with a high risk of aspiration, nasojejunal tubes are preferred. During hospitalization, the use of commercial formulas is advised due to a lower incidence of reported infections. The selection of enteral formula types follows the same specifications as ONS and must be based on energy needs through macro and micronutrients [18,19,44] (Table 2 and Table 3).

10. Recommendations on the Use of Parenteral Nutrition

Parenteral Nutrition (PN) is defined as the set of procedures carried out to administer nutrients intravenously through a catheter.

PN is indicated when tube-based EN is contraindicated due to [62]:

• Gastrointestinal dysfunction
• Intolerance to EN for more than 3 to 7 days
• Intestinal obstruction
• Hollow viscus perforation
• Necrotizing pancreatitis with intolerance to EN
• Intractable vomiting and/or diarrhea
• Severe enteritis
• Intestinal ischemia
• High-output enteral fistula (greater than 500 mL per day)
• Need for bowel rest or fasting for more than 7 days
• Short bowel syndrome or type III intestinal failure.

PN is more expensive and increases the risk of thrombophlebitis, infections, and metabolic complications compared to EN. However, early initiation of PN in hospitalized patients with ORM reduces the risk of infectious complications and in-hospital morbidity and mortality. Therefore, PN must be properly indicated and calculated, avoiding prolonged underfeeding or overfeeding, and the nutrient supply must be personalized for each clinical condition associated with obesity [34,43] (Table 2 and Table 3).

During monitoring, assess the absence of metabolic complications associated with overfeeding, such as hepatic steatosis, cholestasis, hyperglycemia, hypertriglyceridemia, CO₂ retention, azotemia and hydroelectrolytic imbalances. The care team must also monitor for infections, which mainly derive from catheter care and PN admixture [62].

11. Recommendations on the Use of Immunonutrients

The immunonutrients mentioned below tend to be deficient in patients with ORM for various reasons, the most notable being due to hyper-metabolism secondary to inflammation, malnutrition, alterations in the antioxidant system, and immunosuppression, which is why this section describes the supplementation indications for each of them.

11.1. Omega-3

Due to its anti-inflammatory, immunomodulatory, and metabolic effects, it is recommended to supplement 2 to 3 g per day of Eicosapentaenoic Acid (EPA) plus docosahexaenoic acid (DHA) via PO or EN [63,64,65]. In hospitalized individuals with ORM, a dose of 0.1–0.2 g/kg/day in PN is recommended, if they are hemodynamically stable and do not have severe coagulopathies [19].

11.2. Vitamin D₃ (1.25 Dihydroxycholecalciferol)

The high prevalence of vitamin D deficiency is one of the reasons why supplementation is needed at doses of 4000–5000 IU/day (100–125 mg/day). It should be administered for two months in patients with ORM who present with vitamin D deficiency with serum 25(OH) vitamin D levels below 20 ng/mL (Grade B, Strong consensus) [66].

11.3. Glutamine and/or Arginine

Specific amino-acids, as arginine: 14 g/day, glutamine: 14 g/day, and β- hydroxy-β-methyl butyrate (βHMB): 2.4 g/day) could be administered to support wound healing or pressure ulcers (Grade 0, Strong consensus). Also, glutamine-alanine could be administered at doses of 0.3 to 0.5 g/kg/day, orally or via EN for 10 to 15 days in patients with burns >20% of body surface area (Grade 0, Strong consensus). Provided that the patient is hemodynamically stable and does not have renal or hepatic failure (Grade A, Strong consensus) [13]. However, there is no specific evidence for hospitalized patients with ORM [19]. Its potential benefit is currently under study in patients with diabetic foot conditions [67].

11.4. Antioxidant and Immunomodulatory Vitamins and Minerals (Vitamin C, E, B-Complex, Beta-Carotene, Selenium, and Zinc)

Do not administer more than 10 times the DRIs (safe range is 5 to 10 times), and only if the patient is hemodynamically stable and there are clinical signs and/or blood test results confirming the deficiency [31,68]. In cases of RS, consider administering 300 mg of thiamine before starting feeding and during the first 7 to 10 days following initiation [38].

11.5. Prebiotics and Probiotics

In patients with ORM, the addition of prebiotics such as fructooligosaccharides, inulin, pectin, and β-glucans, as well as multistrain probiotics containing Bifidobacterium spp., Lactobacillus spp., Faecalibacterium prausnitzii, and Akkermansia muciniphila may help prevent or treat GM dysbiosis, increase the production of short-chain fatty acids (such as butyrate), and reduce the translocation of food antigens and bacterial lipopolysaccharides (LPS), thereby decreasing inflammation and insulin resistance [18,69,70,71,72].

12. Monitoring

During hospitalization, the anthropometric measurements, biochemical data, clinical examination findings, dietary, and lifestyle parameters should be assessed at least three times a week in stable patients and daily in critically ill patients. This monitoring should focus on indicators of overeating, such as hyperglycemia, hypertriglyceridemia, carbon dioxide retention, weight or body fat gain, etc. [73] For hospitalized patients with Type 2 or Type 1 diabetes who are not eating, check blood glucose levels at least every 4 to 6 h. More frequent checks may be necessary for those at greater risk of hypoglycemia. An overview of the nutritional care process and its key considerations can be summarized as shown in Figure 1.

13. Conclusions and Future Directions

Individuals with ORM experience more complications and are exposed for longer periods to hospital environmental factors that lead to rapid losses of muscle mass and increased inflammatory response in adipose tissue, resulting in the deterioration of nutritional status, impaired metabolic control, and increased morbidity and mortality. Therefore, nutritional management of hospitalized patients with ORM poses a challenge for several reasons, such as:

• Malnutrition is underdiagnosed in individuals with obesity. This is because a specific nutritional screening program for people with obesity that considers metabolic morbidity, sarcopenia, symptoms of nutrient (antioxidant) deficiency, inability to feed orally, and infections has not been developed. This leads to delayed and inadequate medical and nutritional care.
• There are no specific guidelines for calculating total energy requirements (alternatives to IC), determining fluid, protein, specific amino acids, and immunonutrient requirements.
• In multimorbidity conditions, signs and symptoms are highly diverse, and if they are not integrated and analyzed as a whole, as established by the NCP, contradictory re-commendations could result. For example, for patients with sarcopenic obesity or critically ill patients, current guidelines recommend a high protein intake; however, those with coexisting kidney, liver, or heart failure may require fluid restrictions, which would prevent them from achieving the necessary protein intake. Also, the use of PN in ORM with kidney, liver, and heart failure and sarcopenic obesity should be addressed with caution. For now, it is recommended to prioritize the problem to be treated according to the maximum clinical benefit.
• Furthermore, the clinical, social, cultural, and psychological characteristics of each person influence dietary decisions to improve long-term adherence.
• For these reasons, it is necessary to create more lines of research that standardize nutritional recommendations by degree, phenotype, and causality of obesity and type of comorbidity. This way, health professionals who make up the multidisciplinary nutritional support teams will have better tools for decision-making when faced with the challenge of selecting and integrating the most appropriate nutritional approach for hospitalized patients with ORM.