Guideline Nutritional Care in Amyotrophic Lateral Sclerosis (ALS)

Why Nutrition Matters in ALS

ALS is a progressive neurodegenerative disease that leads to muscle weakness, dysphagia, and increased metabolic demands. Malnutrition and unintended weight loss are common and are associated with faster functional decline, reduced respiratory capacity, and shorter survival. Early, systematic nutritional assessment and intervention are therefore core components of multidisciplinary ALS care.

Key Recommendations

1. Screen all patients for nutritional risk at diagnosis. Use a validated tool such as the ALS Functional Rating ScaleRevised (ALSFRSR) combined with weightchange history, BMI, and appetite assessment.
2. Perform comprehensive baseline assessment. Include weight, height, BMI, body composition (if available), serum albumin, prealbumin, and a detailed dietary intake questionnaire.
3. Institute regular monitoring. Reevaluate weight, BMI, and oral intake every 13months, or sooner if there is a rapid change in disease status.
4. Target energy intake. Aim for 3035kcal/kg ideal body weight per day, adjusting upward for hypermetabolism (up to 40kcal/kg). For patients with BMI<20kg/m, consider an additional 300500kcal per day.
5. Prioritize protein. Recommend 1.21.5g protein/kg ideal body weight daily; higher amounts (up to 2g/kg) may be needed when respiratory muscle weakness is present.
6. Address dysphagia early. Conduct a formal swallow assessment (clinical bedside exam plus videofluoroscopic or fiberoptic endoscopic evaluation) within 3months of diagnosis.
7. Implement texturemodified diets only when absolutely necessary. Use thickened liquids and soft foods after speechlanguage pathologist recommendation; avoid overly restrictive diets that reduce caloric density.
8. Consider enteral nutrition when oral intake falls below 75% of estimated needs for >2weeks or when weight loss exceeds 5% of baseline. Prefer percutaneous endoscopic gastrostomy (PEG) before respiratory decline (FVC50%).
9. Provide multidisciplinary support. Dietitian, speechlanguage pathologist, neurologist, physiotherapist, and respiratory therapist should collaborate on individualized nutrition plans.
10. Educate patients and caregivers. Offer written and verbal guidance on highcalorie, nutrientdense foods, fluid management, and the use of oral supplements.

Assessment Tools

1. Anthropometry

• Weight and height (BMI calculation).
• Midupper arm circumference or skinfold thickness for lean body mass.

2. Laboratory Markers

• Serum albumin, prealbumin, and transferrin (interpret with caution inflammatory status influences values).

3. Dietary Intake

• 24hour recall or 3day food record.
• Use of validated questionnaires such as the Mini Nutritional Assessment (MNA) or Subjective Global Assessment (SGA).

4. Swallowing Evaluation

• Clinical bedside screen (water swallow test).
• Instrumental studies: videofluoroscopic swallow study (VFSS) or fiberoptic endoscopic evaluation of swallowing (FEES).

Oral Nutrition Strategies

• Calorie density. Add healthy fats (olive oil, nut butter) or commercial highcalorie supplements to meals.
• Meal frequency. Offer 56 small meals/snacks rather than three large meals.
• Texture modifications. Use pureed or mechanically altered foods only after formal assessment; maintain variety to improve appetite.
• Hydration. Encourage thickened fluids if needed; monitor for aspiration risk.

Enteral Nutrition (PEG or RIG)

Indications:

• Weight loss >5% in the preceding 6months.
• Oral intake <75% of estimated needs for >2weeks.
• Significant dysphagia with aspiration risk.

Timing is critical: placement should be performed while forced vital capacity (FVC) is 50% predicted to reduce periprocedural respiratory complications. Postplacement, target the same caloric and protein goals as oral feeding, using polymeric formulas or diseasespecific blends (e.g., highprotein, fiberrich). Monitor tube patency, skin integrity, and nutritional parameters every 46weeks.

Special Considerations

Hypermetabolism

Up to 60% of ALS patients demonstrate increased resting energy expenditure. Indirect calorimetry, when available, provides the most accurate assessment; otherwise, calculate using predictive equations and adjust based on weight trends.

Respiratory Muscle Weakness

Protein requirements rise with respiratory compromise to support diaphragmatic function. However, excessive carbohydrate intake can increase CO production; a balanced macronutrient distribution (3035% fat, 4555% carbohydrate, 2025% protein) is advisable.

Constipation

Reduced mobility and limited fluid intake predispose to constipation. Include fiberrich foods, adequate fluids (2L/day unless contraindicated), and consider osmotic laxatives early.

Vitamin and Micronutrient Supplementation

Routine supplementation is not universally required. Provide vitamin D (8001000IU/day) and calcium (1000mg/day) if bone density is low. Correct deficiencies (e.g., B12, iron) based on laboratory findings.

FollowUp and Outcome Measures

Regular followup should document:

• Weight change (target 0.5% loss per month).
• BMI trajectory.
• ALSFRSR respiratory subscore.
• Qualityoflife assessments (e.g., ALSAQ40).

Studies show that maintaining or gaining weight, and early PEG placement when indicated, are associated with a 612month survival benefit and improved functional scores.

Implementation in Clinical Practice

1. Integrate nutrition screening into the initial neurology visit.
2. Establish a referral pathway to a registered dietitian with ALS experience.
3. Schedule multidisciplinary case conferences at least every 3months.
4. Document nutrition goals in the electronic health record and set alerts for weight loss thresholds.
5. Provide educational handouts and video resources for home caregivers.

References

1. American Academy of Neurology. Practice guideline: Disease-modifying therapies for ALS. Neurology, 2022.

2. Miller, R.G., et al. Nutritional management in ALS. Lancet Neurology, 2021.

3. Jasim, S., et al. Hypermetabolism in ALS: Clinical implications. Neurology Clinics, 2020.

4. Royal College of Physicians. Guidelines for the use of enteral nutrition in ALS. 2023.

5. Pagnini, A., et al. Swallowing assessment and PEG timing in ALS. Clinical Nutrition, 2022.