Muscle-targeted nutrition therapy in rehab
Loss of muscle mass (for any reason) can lead to physical disability, reduced independence, increased risk of falls and poor quality of life. After a major trauma, loss of muscle mass is usually a consequence of muscle disuse, inflammation and/or inadequate nutrition. This loss of muscle can be classified in two main ways:
a) Muscle disuse atrophy – where the muscle fibres get smaller but the overall number of muscle fibres remain the same;1 or
b) Sarcopenia – where the muscle fibres get smaller AND the number of muscle fibres reduce and become infiltrated with fat.1 This muscle has a reduced ability to recover and regenerate.1 To be labelled as sarcopenia, you need to see a decrease in muscle strength, in addition to a decrease in muscle quality, quantity and/or performance.2 Sarcopenia is a chronic condition caused by a number of factors including age-related changes to sex hormones and mitochondrial function, endocrine changes, muscle disuse, inadequate nutrition, cachexia and/or chronic disease.3
How is muscle mass/strength/performance measured?
*Note: these tests are designed for the general population. Adjust as appropriate for clients with a brain injury or spinal cord injury.
- Sarcopenia – the SARC-F questionnaire is the easiest way to diagnose sarcopenia.
- Muscle mass – In a community setting where DXA, MRI and CT scans are not available, muscle mass can be assessed using calf-circumference or bioelectrical impedance.2
- Muscle strength can be measured using a chair-stand test or hand dynamometer for grip strength.2
- Muscle performance can be measured using gait speed or the Timed-Up-And-Go test.2
Top 5 ways to treat muscle atrophy and sarcopenia with nutrition + physical activity
1. Resistance training
To build muscle, you need both muscle contraction (from resistance exercise or neuromuscular stimulation) and food intake (specifically dietary protein).4 Eating dietary protein will not increase muscle mass unless it is paired with resistance training. Resistance training also helps make your body more sensitive to the protein you do eat, so that your body is able to use it better. 4
2. Ensure a sufficient protein intake.
Muscle disuse alone can cause muscle mass to decline (by as much as 1.4kg in 7 days!5). If you combine this with an inadequate protein and calorie intake as well, the problem is further compounded. The role of an adequate protein intake in situations of muscle disuse (eg. someone being bed bound), is to minimise the amount of muscle that is lost.6
Protein requirements are based on body weight, activity levels and other factors such as wound healing, and so should ideally be calculated for each client. Getting enough protein can be a challenge when someone isn’t feeling well or when someone requires high amounts of protein and yet needs only a small number of calories in order to maintain their weight. Once protein needs are met, adding extra protein over and above this doesn’t prevent muscle loss any further.4
3. Consider protein “dose” and timing
There is a limit to how much protein your body can use at one time. While the exact “dose” will depend on someone’s body weight, consuming high quality protein in 4 x ~20-30 gram “doses” throughout the day, provides maximum muscle protein synthesis.7 Examples of 20-30 grams of protein include: a high protein yogurt, one tin of tuna or 4 eggs. Consuming more protein than this at one time offers no additional benefit. Clients who eat very little protein during the day, but then eat a lot in the evening, won’t be getting the full benefit from their protein intake. Doing physical activity before eating, helps to stimulate muscle protein synthesis even more.4 Older adults should aim for the top end of the range, as higher doses of protein are needed to stimulate muscle protein synthesis the older someone gets.8
4. Protein quality matters too
Protein which contains all essential amino acids is considered higher in quality. High quality protein sources includes: eggs, chicken, fish, milk, meat and soy. These foods are also high in the amino acid leucine, which is of particular interest in muscle synthesis, because it helps stop muscle protein from being broken down.4 Of all the protein sources, whey is the highest in leucine. Research has found that nutrition supplements containing 20grams whey protein and enriched to provide ~3grams leucine, are effective at improving muscle mass and strength in people with sarcopenia.9
5. Check vitamin D levels
Vitamin D deficiency has a negative impact on muscle strength and performance and increases the risk of sarcopenia.10 Ensure clients have their vitamin D levels checked and any deficiencies corrected. Adding 800IU vitamin D per day to the leucine-enriched whey protein supplement mentioned above, has been found to have a positive impact on muscle mass and performance.9
Nutrition matters, particularly in a rehab setting where we are usually aiming to improve muscle mass, strength and performance. For more information on muscle-targeted nutrition therapy, or to make a referral, contact Specialist Nutrition Rehab at 0121 384 7087 or email@example.com.
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