What nutritional guidelines should be followed for adult in-patients, considering age, medical history, and current diagnosis?

Calculating Diet for Inpatients: A Structured Approach

For adult inpatients, calculate energy needs at 27 kcal/kg actual body weight/day and protein at 1.2-1.5 g/kg/day, using actual body weight as the baseline measurement, with adjustments based on specific clinical conditions such as severe underweight (30 kcal/kg) or severe renal impairment (0.8 g protein/kg). 1

Step 1: Screen for Nutritional Risk on Admission

• Use validated screening tools (NRS-2002 or MNA-SF) on all patients at hospital admission to identify those requiring detailed nutritional assessment 1
• Screening identifies patients at risk who will benefit from nutritional intervention, reducing complications and length of stay 1
• If screening is positive, proceed immediately to detailed assessment—do not wait for severe malnutrition to develop 1

Step 2: Perform Detailed Nutritional Assessment

Gather the following specific data points:

• Body measurements: Current weight, height, BMI, recent weight loss (>5% in 3 months or >10% total) 1
• Medical history: Underlying diseases, severity of illness, presence of inflammation, kidney function (eGFR), pressure ulcers 1
• Social/functional factors: Living conditions, ability to shop/prepare food, dentition/swallowing problems, cognitive status, depression 1, 2
• Current intake: Food consumption over past week—if ≤50% of portions consumed for 3 days, trigger immediate intervention 1
• Biochemical markers: Albumin (low albumin predicts complications), hemoglobin, renal function 3, 4

Step 3: Calculate Energy Requirements

Use these specific formulas based on patient characteristics:

For Polymorbid Older Patients (≥65 years):

• Total Energy Expenditure (TEE): 27 kcal/kg actual body weight/day 1
• Resting Energy Expenditure (REE): 18-20 kcal/kg actual body weight/day (then add activity/stress factors) 1
• This is based on indirect calorimetry data from 2,450 subjects showing weighted mean REE of 20.4 kcal/kg in older adults 1

For Severely Underweight Patients (BMI <16):

• Target: 30 kcal/kg actual body weight/day 1
• Critical warning: Achieve this target slowly and cautiously due to high refeeding syndrome risk 1
• Monitor phosphate, magnesium, and potassium closely during refeeding 1

For Patients with Severe Renal Impairment (eGFR <30 ml/min/1.73m²):

• Energy: Standard calculations apply (27 kcal/kg/day for older adults) 1
• Protein restriction required (see protein section below) 1

General Inpatients Without Special Conditions:

• Use indirect calorimetry when available for most accurate measurement 1
• If indirect calorimetry unavailable, use weight-based formulas as starting point 1

Step 4: Calculate Protein Requirements

Use actual body weight for all calculations:

• Standard polymorbid inpatients: 1.2-1.5 g protein/kg/day 5
• Healthy patients: 1.0-1.2 g protein/kg/day 5
• Patients with cachexia or sarcopenia: >1.5 g protein/kg/day 5
• Severe renal impairment (eGFR <30, not on dialysis): 0.8 g protein/kg/day 1
• Patients with pressure ulcers: Add arginine, glutamine, and β-HMB to standard protein targets 1

Distribute protein evenly across meals at approximately 0.4 g/kg body weight per meal for optimal utilization 2

Step 5: Address Micronutrient Needs

Mandatory supplementation for all older inpatients:

• Vitamin D: 15 μg (600 IU) daily throughout hospital stay 2
• Vitamin B12: 4-8.6 μg daily (absorption impaired in 12-15% of elderly; higher in those on PPIs/antacids) 2
• Calcium: 950 mg daily from food sources; add 500 mg supplement if consuming <1 dairy portion daily 2

Conditional supplementation:

• Multivitamin/mineral supplement if consuming <1500 kcal/day (cannot meet micronutrient needs from food alone) 2
• Monitor and replace deficiencies: Iron (goal 11 mg/day), zinc (7.5-12.7 mg/day), vitamin C (95 mg/day), folate (330 μg/day) 2
• Never treat folate deficiency before checking and treating B12 deficiency (critical warning) 2

Step 6: Design the Meal Plan

Provide high-energy, high-protein hospital diet with these specifications:

• Protein delivery: 75g per day minimum, distributed equally across three main meals 1
• Volume: Reduce to 2/3 of usual volume while increasing energy/protein density 1
• Meal frequency: 5-6 small meals per day to maximize absorption and minimize metabolic stress 5
• Fiber: 25g daily (use soluble/insoluble fiber mix in enteral formulas for older patients) 1, 2
• Sodium: <2,300 mg/day 5
• Fluid: 1.6 L/day for women, 2.0 L/day for men 2

Avoid hypocaloric diets—they increase malnutrition risk even in obese patients 1, 5

Step 7: Monitor Food Intake and Trigger Interventions

Daily monitoring requirements:

• If patient consumes ≤50% of portions for 3 consecutive days, immediately escalate intervention 1
• This threshold is based on NutritionDay® survey data showing 2-8 fold increased mortality with <50% intake 1
• Use 10-point visual analog scale for food intake assessment (score <7 indicates high nutritional risk) 1

Escalation pathway when oral intake insufficient:

1. First: Nutritional counseling by dietitian 1
2. Second: Add oral nutritional supplements (ONS) 1
3. Third: Enteral nutrition (tube feeding) if oral route inadequate 1
4. Fourth: Parenteral nutrition if enteral route contraindicated 1

Step 8: Adjust for Specific Clinical Conditions

Refeeding syndrome risk (starvation >10 days, weight loss >15%, low magnesium <0.7 mmol/L):

• Start at lower caloric target and advance slowly 1
• Monitor phosphate, magnesium, potassium, glucose closely 1
• Low serum magnesium is the only significant predictor of refeeding syndrome 1

Diabetes management:

• Target glucose 140-180 mg/dL in elderly (tighter control increases hypoglycemia mortality risk 1.81-3.21 fold) 3
• Use consistent carbohydrate content at each meal 5
• Never discontinue basal insulin in type 1 diabetes even with poor intake 3

Cognitive impairment/dementia:

• Focus on portion sizes and healthy food choices rather than complex meal planning 5
• Avoid restrictive diets that increase sarcopenia risk 5, 3

Common Pitfalls to Avoid

• Do not use precise weight-based formulas as absolute targets—they are starting points requiring clinical judgment and adjustment 1
• Do not wait for severe malnutrition to develop before intervening—start nutrition therapy as soon as risk is identified 1
• Do not use "no concentrated sweets," "no added sugar," or "liberal diabetic diets"—these meal plans are inappropriate 5
• Do not prescribe hypocaloric diets in the hospital setting—they worsen malnutrition even in obese patients 1
• Do not use sliding-scale insulin alone—associated with poor outcomes and higher hypoglycemia rates 3
• Do not ignore refeeding syndrome risk in severely underweight patients—advance calories cautiously 1