Energy Imbalance

To maintain a healthy weight, one must stay in energy balance whereby energy intake equals energy expenditure. Total daily energy expenditure is determined by three factors: resting metabolic rate, physical activity and the thermic effect of food. In addition to lifestyle practices (e.g., smoking) each of these factors is altered following a SCI, rendering it challenging for patients to achieve and maintain energy balance (De Groot et al. 2008). The resting metabolic rate of people with chronic SCI is estimated to be 14-27% lower than their non-SCI counterparts, largely due to reductions in fat-free mass and reduced sympathetic nervous system activity (Buchholz & Pencharz 2004). Physical activity levels of persons with SCI are generally lower than that of non-SCI persons (Buchholz & Pencharz 2004). In addition, a lower thermic effect of food has been reported in persons with a SCI compared to non-SCI controls (Monroe et al. 1998). Three studies have examined dietary intake and malnutrition in the SCI population (Pellicane et al. 2013; Sabour et al. 2012; Wong et al. 2012).

Discussion

To ensure adequate dietary intake in a SCI population, regulating the constituents of one’s diet is important. Sabour et al. (2016) found that a higher protein intake of essential amino acids is associated with a lower bone mineral density in the lumbar vertebrae of a SCI population. Lieberman et al. (2014) evaluated dietary guideline adherence in individuals with SCI, and found that they consume fewer daily servings of fruit, dairy and whole grains when compared to age-matched controls. This is of concern as Tsunoda et al. (2015) identified in their study of a Japanese SCI population, that total consumption of vegetables, dairy products and fruits is a differentiating factor between those with superior and subordinate healthy diet habits.

Pellicane et al. (2013) found that among four populations (i.e., SCI, stroke, traumatic brain injury, and Parkinson’s disease), mean caloric intake, but not protein intake, was significantly higher in the SCI population compared to the others (p=0.004). Both Pellicane et al. (2013) and Sabour et al. (2012) reported that age and gender were significant predictors of calorie and protein intake. Further, Sabour et al. (2012) found that simple carbohydrate consumption was excessive among their sample. There were no differences in calorie intake between those with tetraplegia versus paraplegia.

Excessive or limited dietary intake can leave individuals at risk for malnutrition. Wong et al. (2012) examined rates of malnutrition among individuals with SCI on admission to hospital. The authors reported that 40.0% of the sample were found to be nutritionally ‘at risk’ and 21.4% were assessed as being ‘at high risk’ of malnutrition. Wong et al. (2014) also demonstrated that undernutrition is associated with worse clinical outcomes in the year after a SCI. Patients that were undernourished had significantly longer length of stays in rehabilitation (p=0.012), and a greater 12-month mortality rate (p=0.036). Thus, there are a significant number of individuals at risk of developing further nutrition-related complications post SCI.

A study by Krempien and Barr (2012) examined eating behaviours and attitudes of professional Canadian Paralympians with a SCI. The authors found that in reference to average individuals with SCI, these athletes had good control of: eating to maintain body weight and composition, knowledge of the types of food they were eating, and were less responsive to physiological hunger cues.

Given alterations in resting energy expenditure, it can be challenging to accurately estimate daily energy requirements for individuals with post-acute SCI. Equations validated and used in non-SCI populations to predict resting metabolic rate overestimate actual measured energy needs in the SCI population (Buchholz & Pencharz 2004). However, Gorgey et al. (2015) found that in a chronic SCI population, caloric intake was on average much lower than the total energy expenditure and basal metabolic rate of this population. Therefore, it has been suggested that energy needs following SCI are best assessed by indirect calorimetry using a metabolic cart (Hadley 2002). Because not all health care centers have access to metabolic carts to measure resting metabolic rate, validated equations specific to the SCI population are needed.

Conclusions

There is level 5 evidence (from one observational study: Sabour et al. 2016) that elevated protein intake can lower bone mineral densities in individuals with SCI.

There is level 5 evidence (from two observational studies: Tsunoda et al. 2015; Lieberman et al. 2014) that consumption of whole grains, vegetables, fruits and dairy products are important in maintaining adequate dietary intake.

There is level 5 evidence (from two observational studies: Pellicane et al. 2013; Sabour et al. 2012) that age and gender, but not level of injury, predict total caloric intake in individuals with SCI; further, level 5 evidence (from one observational study; Gorgey et al. 2015) suggests that individuals with chronic SCI often have a negative energy balance, consuming fewer calories than they burn.

There is level 5 evidence (from two observational studies: Wong et al. 2014; Wong et al. 2012) that individuals with SCI are at a significant risk for malnutrition and are at risk of worse clinical outcomes in the first year after injury.