Changes to energy requirements

Total daily energy expenditure

Total daily energy expenditure is the amount of energy required by the body during a 24-hour period. There are three separate components that contribute to a person’s total daily energy expenditure:  

1. Resting metabolic rate is the minimum amount of energy required to maintain the basic processes of life. It is predominantly influenced by body size and body and accounts for majority of total daily energy expenditure in a healthy person (~70%). 
2. Activity energy expenditure is the energy used above resting needs for any planned or incidental physical movement, mental and emotional stimulation. It can account for approximately 20% of total daily energy expenditure in active individuals. 
3. Thermic effect of food is the energy required by the body to digest and store nutrients, and usually accounts for approximately 10% of total daily energy expenditure. 

Total daily energy expenditure after a spinal cord injury 

Total daily energy expenditure is significantly reduced following spinal cord injury (SCI) because of a:

1. Decrease in resting metabolic rate due to substantial reductions in muscle mass, increases in fat mass, loss of bone mineral density and changes to sympathetic nervous system activity.
2. Decrease in activity energy expenditure due to reduced movement and denervated muscles.
3. Potential decrease in the thermic effect of food.

This is summarised in the diagram below: 

Why the reduction in daily energy requirements is important

If the total amount of food (energy) consumed each day is not reduced to match the decrease in daily energy requirements, weight gain will occur. Studies show that people with SCI gain a significant amount of weight in the first 12 months after leaving rehabilitation, although weight gain can occur at any time.

Weight gain has far-reaching impacts on a person with SCI and can lead to: 

• Increased respiratory effort
• Reduced independence, including the inability to transfer  
• Pressure injuries  
• Outgrowing of equipment 
• Increased pain levels 
• Decreased quality of life
• Development of cardiometabolic diseases and other chronic health conditions

Weight gain prevention and management

Early education and support from a dietitian and the wider health care team is vital. Regular weight monitoring, both in the inpatient setting and the community, is also crucial. See weight gain prevention after spinal cord injury for more information.