Why ALS Patients Need More Calories
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that causes progressive muscle weakness. However, despite muscle atrophy, many individuals with ALS experience hypermetabolism, meaning their body burns more calories at rest. This phenomenon is not fully understood but is thought to be caused by the increased workload on remaining muscles and the body's inflammatory response to the disease. A significant increase in metabolic rate, up to 20% higher than average, can occur. This creates a high-risk situation for malnutrition, which can have a serious impact on a patient's prognosis. A weight loss of just 5% can increase mortality risk by 30%. For this reason, maintaining or gaining weight is a key therapeutic goal, and addressing caloric needs is the first step.
General Guidelines for Estimating Calorie Needs
Healthcare professionals generally estimate calorie needs for non-ventilated ALS patients in the range of 30-35 kcal/kg of body weight per day. This is a starting point and should be adjusted based on individual factors such as activity level, weight changes, and overall clinical status. For patients using non-invasive ventilation, the caloric requirements are typically lower, estimated at 25-30 kcal/kg per day. It is crucial to work with a registered dietitian and the ALS care team to determine the most accurate and personalized caloric intake.
For example, an ALS patient weighing 70 kilograms would require approximately 2,100 to 2,450 calories per day to maintain their weight, a significant increase over the average sedentary person. However, meeting this target can be difficult due to several challenges associated with the disease.
Common Challenges to Meeting Nutritional Requirements
Several symptoms of ALS can interfere with a person's ability to eat and drink enough to meet their high energy demands.
- Dysphagia: Difficulty chewing and swallowing is a hallmark of ALS, especially in bulbar-onset cases. This can lead to longer meal times, fatigue during eating, and an increased risk of choking or aspirating food or liquids into the lungs.
- Fatigue: The effort required for eating can be exhausting for patients with muscle weakness, causing them to consume less than they need. The simple act of preparing and consuming a meal can burn more calories than are ingested, creating a negative energy balance.
- Loss of Appetite: Reduced mobility, depression, and other physical factors can lead to a loss of appetite, further reducing overall food intake.
- Increased Mucus: Some patients experience thicker saliva, which can make swallowing more difficult. Staying adequately hydrated can help, but thickened liquids may be necessary.
Strategies to Increase Caloric Intake
To combat weight loss and meet elevated calorie needs, a comprehensive approach is necessary. Here are some strategies recommended by dietitians and ALS care teams:
- Fortify Foods: Add extra calories and protein to existing foods without increasing the volume. Examples include stirring powdered milk into sauces, using whole milk or cream instead of water, and adding cheese or nut butter to meals.
- Smaller, More Frequent Meals: Instead of three large meals, patients may benefit from 6 to 8 smaller, high-calorie meals or snacks throughout the day. This reduces fatigue and ensures a more consistent intake of nutrients.
- Focus on Nutrient-Dense Foods: Choose foods that pack a lot of calories into a small serving. Good options include avocados, nut butters, Greek yogurt, and olive oil.
- Texture Modification: As swallowing becomes more difficult, food consistency can be altered. Pureeing foods, adding gravies or sauces, or eating naturally soft foods like scrambled eggs can make meals safer and easier to consume.
- Nutritional Supplements: High-calorie, high-protein shakes can help fill nutritional gaps, especially on low-energy days or as oral intake declines.
Oral Feeding vs. PEG Tube Feeding: A Comparison
For many patients with ALS, the decision to use a percutaneous endoscopic gastrostomy (PEG) feeding tube is a critical one. It's often recommended when weight loss becomes significant or swallowing poses a serious risk. The following table outlines a comparison of the two main feeding methods.
| Feature | Oral Feeding | PEG Tube Feeding |
|---|---|---|
| Primary Goal | Enjoyment, social interaction, nourishment | Safe and efficient delivery of nutrition and hydration |
| Swallowing Safety | Risk increases with disease progression; choking and aspiration are major concerns | Significantly reduces risk of aspiration and choking once established |
| Nutritional Adequacy | Can be challenging to maintain due to fatigue, appetite loss, and dysphagia | Ensures consistent, adequate intake of calories, fluids, and medication |
| Energy Expenditure | High during meals; can lead to increased fatigue | Minimal energy expenditure during feeding |
| Weight Management | Difficult to prevent weight loss due to hypermetabolism and low intake | Helps stabilize or increase body weight more effectively |
| Timing of Decision | Can be supplemented with a feeding tube to continue oral intake for pleasure | Discussions should begin early, before significant weight loss or respiratory decline |
The Role of a Multidisciplinary Care Team
Managing the nutritional needs of an ALS patient is a complex process that requires a team approach. The team typically includes a neurologist, registered dietitian, speech-language pathologist (SLP), and occupational therapist.
- Registered Dietitian: Provides personalized recommendations, calculates calorie and nutrient needs, and offers strategies for increasing calorie intake. They are instrumental in managing weight and overall nutrition status.
- Speech-Language Pathologist (SLP): Assesses swallowing function, recommends texture modifications, and teaches safe swallowing techniques to minimize aspiration risk. An SLP is critical for determining when a feeding tube might become necessary.
- Occupational Therapist: Suggests adaptive equipment such as specialized utensils or plates to help patients maintain independence and conserve energy during meals.
Working together, these professionals can develop a proactive plan to address the evolving nutritional challenges posed by ALS, ensuring the patient's nutritional status is monitored and maintained. This proactive stance helps to mitigate the negative consequences of malnutrition and can improve quality of life.
Conclusion
ALS patients require higher caloric intake, often between 30 and 35 kcal/kg per day, to counter hypermetabolism and prevent dangerous weight loss. While this can be challenging due to symptoms like dysphagia and fatigue, strategic interventions can help. These include modifying food textures, incorporating nutrient-dense foods, and considering a PEG tube in more advanced stages. The specific calorie amount for an ALS patient is not a single number but an evolving target, best determined and managed by a multidisciplinary healthcare team. For more information, visit the ALS Association's nutritional considerations page.
