Home / Nutrition & Diet
Nutrition & Diet โ The Metabolic Foundation of Wound Healing
Core concept: Nutrition is the metabolic foundation of wound healing. Inadequate calories, protein deficiency, or micronutrient imbalance directly delays healing and increases the risk of infection and complications. Patients with chronic wounds should undergo routine nutritional screening, with calories and protein requirements individually calculated by population (general, geriatric, burn).
1. How to Assess Nutritional Status
Nutritional assessment is not simply checking body weight; it is a comprehensive judgment integrating screening tools, anthropometric measurements, and laboratory data. For patients with chronic wounds, nutritional screening is recommended at initial presentation and at regular follow-up visits to detect correctable nutritional deficits early.
1.1 Screening Tools
| Tool | Target Population | Grading / Interpretation | Features |
|---|---|---|---|
| SGA Subjective Global Assessment | Hospitalized adults, surgical patients | Grade A (well-nourished), Grade B (moderately malnourished), Grade C (severely malnourished) | Primarily a clinical bedside assessment; includes weight change, dietary intake, gastrointestinal symptoms, functional status, and subcutaneous fat / muscle loss |
| MNA Mini Nutritional Assessment | Elderly (โฅ65 years) | โฅ24 normal; 17โ23.5 at risk; <17 malnourished | Short form (MNA-SF) screens with 6 items; full version provides further grading |
SGA: Detsky AS, et al. JPEN 1987;11(1):8โ13. MNA: Guigoz Y, et al. Nestlรฉ Nutrition 1994 (MNA updated 2006).
1.2 Anthropometric Measurements
| Indicator | Assessment Method | Interpretation |
|---|---|---|
| Weight change | Compare usual weight with current weight; calculate percentage change | Involuntary weight loss: >2% in 1 week, >5% in 1 month, >7.5% in 3 months, >10% in 6 months is significant |
| BMI | Weight(kg) รท Height(m)ยฒ | <18.5 underweight; <22 may be low for Asian elderly; >27 obese (Taiwan criteria) |
| Rate of weight loss | Serial weight trend tracking | Rapid decline reflects acute nutritional deterioration better than a single low value |
1.3 Laboratory Data
| Test | Clinical Significance | Cautions |
|---|---|---|
| Albumin | Reflects long-term protein status; <3.5 g/dL is low | Half-life ~20 days; affected by inflammation, liver function, hydration โ not a nutrition-specific marker |
| Prealbumin | Reflects short-term protein status; half-life ~2โ3 days | More sensitive to acute changes than albumin; also affected by inflammation |
| HbA1c | Reflects 2โ3 month glycemic control | Target generally <7% for diabetic wound patients; may be relaxed to <8% in elderly or those at risk of hypoglycemia |
| Hemoglobin | Anemia affects tissue oxygenation and healing | Iron deficiency anemia: also assess iron, folate, B12; anemia of chronic kidney disease requires EPO evaluation |
Albumin / prealbumin are adjunctive nutritional indicators and must be interpreted in clinical context; they should not be used alone as the sole basis for a nutritional diagnosis (ESPEN consensus; Volkert D, et al. Clin Nutr 2019).
2. Indicators and Staging of Malnutrition
In 2019, the GLIM (Global Leadership Initiative on Malnutrition) proposed an international two-step diagnostic consensus, integrating previous ESPEN and ASPEN definitions to provide a cross-institutional framework for malnutrition diagnosis.
2.1 GLIM Two-Step Diagnostic Process
Step 1: First use a screening tool (SGA, MNA, MUST, etc.) to confirm "at risk of malnutrition."
Step 2: Confirm the diagnosis using GLIM criteria โ at least 1 phenotypic criterion plus 1 etiologic criterion.
Step 2: Confirm the diagnosis using GLIM criteria โ at least 1 phenotypic criterion plus 1 etiologic criterion.
| GLIM Diagnostic Criteria | |
|---|---|
| Phenotypic Criteria | Etiologic Criteria |
| โ Non-volitional weight loss โก Low BMI (Asia <18.5; general <20) โข Reduced muscle mass (MM loss) | โ Reduced food intake or assimilation โก Disease burden / inflammatory response (acute, chronic infection or inflammation) |
GLIM: Cederholm T, et al. Clin Nutr 2019;38(1):1โ11; J Nutr Gerontol Geriatr 2019 (ESPEN/ASPEN consensus).
2.2 Severity Grading
| Stage | Phenotypic Criteria (any one) | Clinical Significance |
|---|---|---|
| Moderate | 5โ10% weight loss in 1โ3 months; or BMI <20 (Asia <18.5) | Requires nutritional intervention and close follow-up |
| Severe | >10% weight loss in 1โ3 months; or BMI <18.5 (Asia <16) | Requires aggressive nutritional support; enteral or parenteral nutrition if necessary |
Staging should incorporate muscle mass assessment; low BMI combined with reduced muscle mass carries higher risk.
GLIM severity grading: Cederholm T, et al. Clin Nutr 2019;38(1):1โ11.
3. How to Improve Nutritional Status in Chronic Wound Patients
Patients with chronic wounds are often in a state of chronic inflammation and catabolic metabolism; simply "eating more" is frequently insufficient. Structured interventions based on individualized calorie, protein, and micronutrient requirements are needed, combined with feeding strategies to improve adherence.
3.1 Calorie Requirements
| Condition | Calorie Recommendation | Notes |
|---|---|---|
| General chronic wounds | 30โ35 kcal/kg/day | Calculated using actual or ideal body weight |
| Underweight / high metabolic demand | 35โ40 kcal/kg/day | BMI <18.5, burns, severe infection, or postoperative recovery |
| Obese patients | Use adjusted body weight | Adjusted weight = ideal body weight + 0.25 ร (actual weight โ ideal weight) |
Pressure injury nutrition: Posthauer ME, et al. Adv Skin Wound Care 2022 (NPUAP clinical guideline). ESPEN geriatric: Volkert D, et al. Clin Nutr 2019.
3.2 Protein Requirements
| Condition | Protein Recommendation | Key Points |
|---|---|---|
| General chronic wounds | 1.25โ1.5 g/kg/day | High-quality protein (animal or complete amino acid sources) should comprise at least 50% |
| High requirement (burns, severe infection, large wounds) | 1.5โ2.0 g/kg/day | Monitor renal function; divide doses if necessary |
| Renal insufficiency | 0.8โ1.0 g/kg/day (per nephrology adjustment) | Coordinate with nephrology; do not unilaterally increase protein solely to "promote healing" |
Protein requirements: ESPEN geriatric guidelines (Volkert 2019); NPUAP pressure injury nutrition (Posthauer 2022).
3.3 Four Key Repair Components
| Component | Mechanism of Action | Recommended Dose | Target Population |
|---|---|---|---|
| Arginine L-Arginine | Nitric oxide (NO) precursor; promotes angiogenesis and blood flow; stimulates collagen synthesis | Oral 5โ10 g/day (9 g/day used in high-risk pressure injury studies) | Pressure injuries, diabetic foot, chronic non-healing wounds |
| Glutamine L-Glutamine | Primary fuel for intestinal epithelium and immune cells; demand increases after trauma; supports immune function | 0.3โ0.5 g/kg/day (commonly used in burns, critical illness) | Burns, major trauma, critically ill patients |
| HMB ฮฒ-hydroxy-ฮฒ-methylbutyrate | Leucine metabolite; anti-catabolic, promotes muscle protein synthesis | 3 g/day (divided doses) | Elderly, high-risk pressure injury, reduced muscle mass |
| Comprehensive micronutrients Vitamin C, Zinc, Selenium | Vitamin C is essential for collagen synthesis; zinc participates in epithelialization and immunity; selenium is a component of antioxidant enzymes | Vitamin C 500 mg/day or higher; zinc 12โ15 mg/day (short-term supplementation) | Chronic wounds, burns, malnourished patients |
โ ๏ธ Supplementation caution: Micronutrients should target "correcting deficiencies"; long-term high-dose zinc (>40 mg/day for several weeks) may cause copper deficiency and immunosuppression. Confirm deficiency or high demand before high-dose supplementation โ do not routinely administer large doses.
Arginine and pressure injuries: Posthauer ME, et al. Adv Skin Wound Care 2022 (NPUAP). Glutamine and burns: Walker H, et al. Burns 2023 (ISBI). HMB and elderly: Volkert D, et al. Clin Nutr 2019 (ESPEN geriatric guidelines).
3.4 Feeding Strategies
- Small frequent meals: 5โ6 meals per day with smaller portions; improves total intake in patients with poor appetite
- Oral nutritional supplements (ONS): Liquid clinical nutrition formulas add calories and protein beyond regular meals; studies show ONS reduces pressure injury incidence in high-risk patients
- Texture modification: Adjust food consistency and thickness for those with chewing or swallowing difficulties; refer to speech therapy or swallowing assessment when needed
- Individualized menus: Design around culture, religion, allergies, and dietary preferences; avoid generic "nutrition formulas" that disregard patient acceptance
- Multidisciplinary collaboration: Dietitians, nurses, and attending physicians jointly track intake records and weight trends
Feeding strategies and ONS: ESPEN geriatric guidelines (Volkert 2019); NPUAP pressure injury clinical practice guideline (Posthauer 2022).
4. Calorie Calculation Formulas for Three Major Populations
Basal metabolic rate (BMR) and total energy expenditure (TEE) estimation differ across populations. The following formulas serve as clinical estimation references; actual delivery should be adjusted and monitored based on individual clinical status.
| Formula | Target Population | Formula |
|---|---|---|
| Harris-Benedict | General hospitalized patients | Male: BMR = 66.47 + 13.75 ร kg + 5.0 ร cm โ 6.76 ร age Female: BMR = 655.1 + 9.56 ร kg + 1.85 ร cm โ 4.68 ร age TEE = BMR ร Activity Factor (AF) ร Stress Factor (SF) |
| Mifflin-St Jeor | Elderly | Male: BMR = 10 ร kg + 6.25 ร cm โ 5 ร age + 5 Female: BMR = 10 ร kg + 6.25 ร cm โ 5 ร age โ 161 |
| Curreri | Burn adults | Calories = 25 ร kg + 40 ร TBSA% (TBSA capped at 50%) |
| Galveston | Burn children | Calories = 1800 ร BSA + 1300 ร burn_area (mยฒ) BSA = body surface area; burn_area = burn surface area (mยฒ) |
4.1 Formula Comparison and Applicable Scenarios
| Comparison | Harris-Benedict | Mifflin-St Jeor | Curreri | Galveston |
|---|---|---|---|---|
| Target population | General adult hospitalized | Elderly | Burn adults | Burn children |
| Year | 1919 (original) / 1984 (revised) | 1990 | 1974 | 1993 |
| Variables included | Weight, height, age, sex | Weight, height, age, sex | Weight, TBSA% | BSA, burn area |
| Activity / stress factor | Yes (AF ร SF) | No (BMR only) | No (direct total calories) | No (direct total calories) |
| Advantages | Widely used; adjustable by activity and stress | Better suited for modern body types; validated in elderly | Directly reflects burn hypermetabolism | Pediatric burn-specific; accounts for body surface area |
| Limitations | May overestimate BMR in obese | Requires additional stress factor | TBSA >50% requires cap correction | Requires precise BSA and burn_area measurement |
Harris-Benedict: Harris JA, Benedict FG. Carnegie Inst 1919 (Publication No. 279). Mifflin-St Jeor: Mifflin MD, et al. Am J Clin Nutr 1990;51(2):246โ249. Curreri: Curreri PW, et al. J Am Diet Assoc 1974. Galveston: Hildreth MA, et al. J Burn Care Rehabil 1993;14(3):336โ340.
4.2 Clinical Reminders
- Edematous patients: Use dry weight or usual weight for calculations; avoid overestimating calorie needs based on edematous weight
- Obese patients: Use adjusted body weight rather than actual weight to avoid overfeeding
- Activity factor (AF): Bedridden 1.2, bedside activity 1.25โ1.3, general activity 1.3โ1.5; add stress factor postoperatively or for infection by severity
- Stress factor (SF): Minor surgery 1.1โ1.2; severe infection 1.2โ1.4; burns 1.5โ2.0 (depending on TBSA)
- Follow-up: Formulas are only starting estimates; adjust continuously based on weight change, clinical response, and laboratory data
โ ๏ธ Overfeeding risk: In bedridden or critically ill patients, excessive calorie delivery may cause hyperglycemia, fatty liver, and increased respiratory burden; reach targets gradually and monitor tolerance.
Burn nutrition clinical guidelines: Walker H, et al. Burns 2023 (ISBI practice guidelines for burn care). ESPEN geriatric: Volkert D, et al. Clin Nutr 2019.
5. Protein and Fat Requirements for Three Major Populations
Protein and fat requirements differ significantly across three populations (general hospitalized, elderly, burn). Burn patients have the highest protein requirements due to hypermetabolism and extensive exudate losses; the elderly must balance muscle maintenance with renal function; general hospitalized patients must balance recovery with baseline needs.
| Comparison | General Hospitalized | Elderly | Burn |
|---|---|---|---|
| Protein g/kg/day | 1.0โ1.5 | 1.0โ1.5 (adjust if renal function limited) | Adults: 1.5โ2.0 Children: 1.5โ3.0 + glutamine 0.3โ0.5 g/kg/day |
| Fat % of total calories | 25โ30% | 25โ30% (rich in Omega-3 recommended) | 20โ30% (Omega-3 at 10โ20%) |
| Additional supplementation | Micronutrients per nutritional assessment | Vitamin D, calcium, B12 per deficiency assessment | Glutamine, arginine, vitamin C, zinc, selenium |
| Special considerations | Glycemic control; avoid overfeeding | Muscle mass maintenance (sarcopenia prevention); swallowing and chewing | TBSA >20% hypermetabolic; early enteral nutrition preferred |
| Formula reference | Harris-Benedict + AF ร SF | Mifflin-St Jeor (+ stress factor) | Curreri (adults) / Galveston (children) |
General hospitalized and elderly: ESPEN geriatric guidelines (Volkert D, et al. Clin Nutr 2019). Burn: Walker H, et al. Burns 2023 (ISBI). Pressure injury: Posthauer ME, et al. Adv Skin Wound Care 2022 (NPUAP).
5.1 Population-Specific Supplementation Notes
| Population | Protein Key Points | Fat Key Points | Clinical Reminders |
|---|---|---|---|
| General hospitalized | 1.0โ1.5 g/kg/day; high-quality protein โฅ50% | 25โ30% E%; saturated fat <10% | May increase to 1.5 g/kg during postoperative recovery; monitor blood glucose and renal function |
| Elderly | 1.0โ1.5 g/kg/day; eGFR <30 requires nephrology coordination | 25โ30% E%; increase Omega-3 (EPA/DHA) to reduce inflammation | Prevent sarcopenia: distribute protein evenly across meals; supplement vitamin D 600โ800 IU/day |
| Burn adults | 1.5โ2.0 g/kg/day; + glutamine 0.3โ0.5 g/kg/day | 20โ30% E%; Omega-3 at 10โ20% of fat | TBSA >30% requires aggressive enteral nutrition; glutamine improves gut barrier and immunity |
| Burn children | 1.5โ3.0 g/kg/day (adjusted by age and TBSA) | 20โ30% E%; moderate Omega-3 | Use Galveston formula for calorie estimation; growth and development require long-term follow-up |
Burn children protein and glutamine: Walker H, et al. Burns 2023 (ISBI). Elderly Omega-3 and sarcopenia: Volkert D, et al. Clin Nutr 2019 (ESPEN geriatric guidelines).
Integrated reminder: Nutritional intervention is not simply giving formulas or supplements โ it is a complete cycle of "screen โ assess โ calculate โ intervene โ follow up." The nutritional plan for chronic wound patients should be integrated with the wound care team, with regular reassessment of weight, protein markers, and wound progress.
References cited on this page:
โข SGA โ Detsky AS, et al. JPEN 1987;11(1):8โ13.
โข GLIM โ Cederholm T, et al. Clin Nutr 2019;38(1):1โ11 (ESPEN/ASPEN consensus).
โข ESPEN geriatric guidelines โ Volkert D, et al. Clin Nutr 2019;38(1):10โ47.
โข NPUAP pressure injury nutrition โ Posthauer ME, et al. Adv Skin Wound Care 2022.
โข Burn nutrition ISBI โ Walker H, et al. Burns 2023;49(3):577โ601.
โข Harris-Benedict โ Harris JA, Benedict FG. Carnegie Institution 1919.
โข Mifflin-St Jeor โ Mifflin MD, et al. Am J Clin Nutr 1990;51(2):246โ249.
โข Curreri โ Curreri PW, et al. J Am Diet Assoc 1974;65(3):293โ296.
โข Galveston โ Hildreth MA, et al. J Burn Care Rehabil 1993;14(3):336โ340.
Full bibliography in the Guidelines Library.
โข SGA โ Detsky AS, et al. JPEN 1987;11(1):8โ13.
โข GLIM โ Cederholm T, et al. Clin Nutr 2019;38(1):1โ11 (ESPEN/ASPEN consensus).
โข ESPEN geriatric guidelines โ Volkert D, et al. Clin Nutr 2019;38(1):10โ47.
โข NPUAP pressure injury nutrition โ Posthauer ME, et al. Adv Skin Wound Care 2022.
โข Burn nutrition ISBI โ Walker H, et al. Burns 2023;49(3):577โ601.
โข Harris-Benedict โ Harris JA, Benedict FG. Carnegie Institution 1919.
โข Mifflin-St Jeor โ Mifflin MD, et al. Am J Clin Nutr 1990;51(2):246โ249.
โข Curreri โ Curreri PW, et al. J Am Diet Assoc 1974;65(3):293โ296.
โข Galveston โ Hildreth MA, et al. J Burn Care Rehabil 1993;14(3):336โ340.
Full bibliography in the Guidelines Library.
Last updated: 2026-09-26