Malnutrition and Oral Nutritional Supplement Prescribing in Adults

Malnutrition remains a common yet often underrecognised problem in adult populations, affecting patients in hospitals, longterm care facilities, and the community. Early identification and appropriate management, including the use of oral nutritional supplements (ONS), can improve clinical outcomes, reduce length of stay, and enhance quality of life.

What Is Malnutrition?

Malnutrition is a state of nutrition imbalance that results from insufficient intake of energy, protein, or other nutrients, or from increased requirements that are not met. It can be classified as:

• Undernutrition deficiency of calories, protein, or micronutrients.
• Overnutrition excess intake leading to overweight and obesity, which can also impair health.

This page focuses on undernutrition in adults, the clinical consequences, and how oral nutritional supplements can be used effectively.

Why Is Malnutrition Important?

Undernutrition in adults is associated with:

• Increased risk of infection and delayed wound healing.
• Loss of muscle mass (sarcopenia) and functional decline.
• Higher rates of hospital readmission and mortality.
• Poor response to medical and surgical treatment.
• Reduced healthrelated quality of life.

Identifying AtRisk Adults

Systematic screening is essential. Common tools include:

Patients with a score indicating moderate or high risk should undergo a full nutritional assessment and, when appropriate, be considered for ONS therapy.

When to Prescribe Oral Nutritional Supplements

Oral nutritional supplements are indicated when any of the following apply:

• Inadequate dietary intake (<75% of estimated needs) for >57 days.
• Weight loss >5% over 36 months.
• Clinical conditions that increase metabolic demand (e.g., infection, trauma, burns).
• Difficulty meeting nutrient needs due to dysphagia, poor appetite, or socioeconomic barriers.

Types of Oral Nutritional Supplements

ONS are available in several formulations. Choice should be guided by individual needs:

• Standard highcalorie, highprotein formulas 1.52.0kcal/mL and 1520g protein per 200mL.
• Proteinfocused supplements higher protein (2030g) with moderate calories, useful in sarcopenia.
• Energydense formulas up to 2.5kcal/mL for patients with very limited volume tolerance.
• Micronutrientenriched drinks fortified with vitamins D, B12, iron, or zinc when specific deficiencies are identified.
• Specialty formulas glutenfree, lactosefree, or diabeticfriendly (lowglycemic) options.

Prescribing Guidelines

1. Assess energy and protein requirements. Use predictive equations (e.g., HarrisBenedict, WHO) adjusted for stress factors, or indirect calorimetry when available.
2. Determine the target contribution of ONS. Typically, ONS should provide 2030% of total energy and protein needs.
3. Select the appropriate formula. Match caloric density, protein content, flavour, and any dietary restrictions.
4. Set the dosing schedule. Common regimens are 12 bottles (200mL each) per day, taken between meals to avoid satiety effects.
5. Monitor tolerance and compliance. Check for gastrointestinal side effects, taste fatigue, or poor adherence.
6. Reevaluate regularly. Review weight, intake, and laboratory markers (e.g., albumin, prealbumin) every 12 weeks initially, then monthly.

Potential Barriers and Solutions

Successful ONS therapy depends on addressing common obstacles:

Clinical Evidence Supporting ONS

Numerous randomized controlled trials and metaanalyses demonstrate that ONS, when combined with dietetic counseling, yields measurable benefits:

• Average weight gain of 24kg over 12weeks in malnourished adults.
• Reduced readmission rates by 1520% in medical inpatients.
• Improved functional scores (e.g., handgrip strength, gait speed) particularly in older adults.
• Shortened duration of wound healing and fewer postoperative complications.

Practical Tips for Clinicians

• Document the indication and prescribed dose in the medication chart.
• Collaborate with dietitians for individualized care plans.
• Involve caregivers in feeding schedules to enhance adherence.
• Use a prescription pad style order that includes brand, strength, volume, and frequency.
• Consider tapering ONS as oral intake improves, transitioning to fortified foods.

Case Example

Patient: 78yearold male, recent hip fracture, BMI 20kg/m, weight loss 6% over 4months.

Assessment: Energy requirement 2100kcal/day; protein 1.3g/kg (95g/day). Current intake 1300kcal/55g protein.

Prescription: Two 200mL bottles of a highprotein, highcalorie ONS (250kcal & 20g protein each) taken midmorning and midafternoon, providing an additional 500kcal and 40g protein.

Outcome (8weeks): Weight gain 2.3kg, improved handgrip strength, able to ambulate with cane, no readmission.

Key Takeaways

• Malnutrition is prevalent and directly impacts clinical recovery.
• Simple screening tools enable early detection.
• Oral nutritional supplements are an evidencebased, costeffective intervention for many atrisk adults.
• Individualised prescribing, regular monitoring, and multidisciplinary collaboration maximise success.

For further reading and detailed guidelines, refer to the British Dietetic Association and the NCCN Clinical Practice Guidelines in Oncology Nutrition.