Nutritional Considerations in Amyotrophic Lateral Sclerosis (ALS)

Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease that primarily affects motor neurons, leading to muscle weakness, dysphagia, and respiratory compromise. Nutrition plays a pivotal role in disease progression, quality of life, and survival. This page summarizes current evidencebased nutritional strategies for people living with ALS.

Why Nutrition Matters in ALS

• Energy imbalance: Muscle wasting increases resting energy expenditure (REE) while dysphagia reduces intake, often resulting in weight loss.
• Weight loss and survival: Prospective studies show that a bodymass index (BMI) < 22kg/m or a loss of >5% body weight predicts shorter survival.
• Respiratory function: Adequate calories support diaphragmatic strength and may delay the need for assisted ventilation.
• Medication absorption: Malnutrition can alter the pharmacokinetics of riluzole and other therapies.

Assessing Nutritional Status

Regular monitoring is essential. Recommended assessments include:

Caloric Requirements

People with ALS often require 125150% of their predicted basal caloric needs. Calculation steps:

1. Estimate basal metabolic rate (BMR) using the MifflinSt Jeor equation.
2. Multiply BMR by an activity factor of 1.21.4 (most patients are largely sedentary).
3. Adjust for increased REE (often +1030%).
4. Target a 0.51kg weight gain per month if the patient is underweight.

Example: A 65yearold male, 70kg, 175cm gives a BMR 1,600kcal. After activity and REE adjustments, total needs may be 2,2002,500kcal/day.

Macronutrient Distribution

• Protein: 1.21.5g/kg ideal body weight per day. Adequate protein supports muscle preservation but should be balanced with caloric load.
• Carbohydrates: 4555% of total calories; preferred for quick energy.
• Fats: 3035% of calories; include omega3 rich sources (fish, flaxseed) for potential antiinflammatory benefits.

Managing Dysphagia

Speechlanguage pathologists should evaluate swallowing early. Strategies:

• Texturemodified diets (pureed, thickened liquids) guided by a certified dietitian.
• Small, frequent meals (68 per day).
• Supplemental highcalorie oral drinks (e.g., Boost, Ensure) between meals.
• Use of chintuck posture while eating to reduce aspiration risk.

Enteral Nutrition

When oral intake supplies < 70% of estimated needs, or weight loss exceeds 5% despite aggressive modifications, consider tube feeding.

Types of tubes

• Nasogastric (NG) tube: Shortterm (< 46 weeks) bridge.
• Percutaneous endoscopic gastrostomy (PEG): Preferred for longterm support; generally placed before a 10% weight loss or FVC < 50% predicted.

Benefits

• Stabilizes weight and may modestly extend survival (average gain of 24months).
• Reduces aspiration pneumonia risk when combined with appropriate positioning.

Considerations

• Discuss timing and expectations with the multidisciplinary team.
• Continue speech therapy to preserve oral skills as long as possible.

Micronutrient Supplementation

Deficiencies are common; targeted supplementation is recommended when labs are low.

Hydration

Dehydration exacerbates constipation and may worsen dysphagia. Aim for 3035mL/kg/day, adjusting for fever, respiratory infections, or diuretic use. Offer fluids in small sips or through thickened liquids if aspiration risk is high.

Special Dietary Patterns

While no single diet has proven diseasemodifying effects, the following have reported benefits in symptom management:

• Highcalorie, highprotein diet: Supports weight maintenance.
• Lowfat, highcarbohydrate diet: May reduce reflux, which can worsen cough.
• Mediterranean diet: Provides antioxidantrich foods; may improve overall health.

Practical Tips for Caregivers

1. Keep a food diary to track intake and adjust portions quickly.
2. Provide nutrientdense foods such as nut butter, avocado, Greek yogurt, and cheese.
3. Use calorieenhancing additives (e.g., oil, butter, powdered milk) in soups and purees.
4. Encourage upright positioning during and after meals (30min) to aid swallowing.
5. Monitor for signs of aspiration: coughing, gurgling, changes in voice.

When to Seek Professional Help

Contact a dietitian or ALS specialist if any of the following occur:

• Weight loss >5% over 12months.
• Inability to meet 70% of caloric goals orally.
• New or worsening dysphagia, frequent choking, or aspiration pneumonia.
• Signs of malnutrition (muscle wasting, edema, low albumin).

Key Takeaways

• Maintaining or modestly increasing weight prolongs survival in ALS.
• Energy requirements are often 125150% of predicted; individualized calculation is essential.
• Early screening for dysphagia and prompt nutritional intervention (texture modification oral supplements tube feeding) improve outcomes.
• Collaborative careneurologist, dietitian, speech therapist, physiotherapist, and caregiversensures the most effective nutritional management.

For further reading, explore resources from the ALS Association and the National Institute of Neurological Disorders and Stroke.