An observational study by Nightingale et al. (2017) provides insight into what characteristics to focus on when designing diet and exercise interventions for SCI patients. 33 individuals wore a physical activity monitor for 7 consecutive days and kept a log of their daily food intake to assess their energy balance using their energy intake and energy expenditure. 31 participants successfully wore the physical activity monitor for at least the minimum required amount of time, and 32 completed the food intake log. The results revealed that both energy expenditure and energy intake were very inconsistent and reported that it takes 1-4 days of monitoring energy expenditure to reliably estimate energy expenditure variables and 4-24 days to reliably estimate total energy intake. The study also reported which covariates effect energy expenditure and energy intake and how much. These results are useful in designing future interventions as it gives researchers the ability to target specific characteristics in order to produce the most useful data regarding diet and exercise and how to generate the best results for patients with SCI.
Li et al. (2018), an RCT in which 11 participants (10 males, 1 female) with SCI were randomized to either 8 wks of combined exercise (Comb-Ex) consisting of resistance and aerobic exercise training with supervision or 8 wks of a high-protein (HP) diet with phone meetings to record compliance and study retention. At the end of the intervention, the HP diet group saw a significantly larger decrease in Matsuda Index scores compared to the Comb-Ex group, whereas the Comb-Ex group saw a their fasting plasma glucose levels decrease significantly more than the HP diet group. Values for area under the curve for insulin and for the pro-inflammatory cytokine TNF-x decreased significantly as well. Results reveal that combined exercise has a significant effect on fasting plasma glucose and high-protein diet has a significant effect on Matsuda Index scores, and both groups improve the area under the curve for insulin and TNF-x for individuals with SCI. It is possible that a regime that incorporates both an HP diet and a Comb-Ex program could potentially provide the best results and this should be a focus of future research.
In an RCT by Gorgey et al. (2012), nine males with chronic SCI were randomized to 12 wk of resistance training plus a diet program or a diet program alone. After the intervention, groups were comparable in body weight and levels of subcutaneous and visceral adipose tissue. However, the treated group had significantly greater increases in skeletal muscle cross sectional areas, insulin growth factor, and fat-free mass; they also experienced reductions in intramuscular fat percentage, the ratio of visceral to subcutaneous adipose tissue, the ratio of plasma insulin to plasma glucose, and triglyceride and HDL-C levels. Resistance training therefore has the benefits of increasing favourable body composition regions through skeletal muscle hypertrophy, which in turn can lead to improvements in carbohydrate and lipid metabolism.
Chen et al. (2006) conducted a study to assess the effect of a weight-loss program on body weight, BMI, waist and neck circumference, skinfold thickness, fat versus lean mass, bone mineral content, blood pressure (BP), serum lipids, hemoglobin, albumin, eating habits, nutrition knowledge, bowel function and indicators of psychosocial well-being. A total of 16 subjects with chronic SCI who were overweight or obese completed the intervention program. Subjects attended 90-minute counseling sessions once per week for 12 weeks, led primarily by a Registered Dietitian. The dietary approach emphasized high-fiber, nutrient-dense foods (e.g., fruits, vegetables, grains, cereals) and the moderation of meats, cheeses, sugars and fats (Weinsier et al. 1983). The program included exercise and behaviour modification. Reported results included an average weight loss of 3.5 kg, significant reductions in BMI, anthropometric measures and fat mass. Lean mass, hemoglobin, albumin and bone mineral content were maintained. There was no significant change in BP or low-density lipoprotein cholesterol (LDL), although there was a significant decrease in high density lipoprotein cholesterol (HDL). There was a trend between weight lost and decrease in waist circumference, increase in nutritional quality of diet, increase in fiber consumption and decrease in time required for bowel movements. Changes in psychosocial and physical functioning were also reported.
Brochetti et al. (2018) is a pretest-post test study similar in design to Chen et al. (2006), as it looks at weight loss, waist circumference with the additional outcome measures of intervention compliance and retention. 18 participants completed a 12-wk interdisciplinary weight management program called Working on Healthy Eating, Exercise and Life Style (WHEELS) that consisted of a dietary component and an exercise program. Those who could not attend meetings or exercise sessions at the program headquarters were able to complete their workouts via satellite sessions, so the program was very accommodating. From baseline to intervention’s end 15 of the 18 participants lost at least 4.5±0.5 kg and 17 of the 18 experienced weight loss of some sort, Also from baseline to post-intervention 16 of the 18 participants experienced a decrease in waist circumference. At the 6-mo follow-up, there were no significant differences in weight or waist circumference with 12/18 participants continuing to lose weight or barely gaining any weight. 11 of the18 participants had decreased Diabetes Risk scores as well. Results from the WHEELS intervention indicate that the program may have clinical benefits as well as show promise for compliance and retention form post-intervention to 6-mo follow-up, which is something that studies to come should seek to duplicate.
While previous studies assessed the physiological effects of nutrition-based weight loss programs, a study by Betts et al. (2017) evaluated the effectiveness of a Diabetes Prevention Program Group Lifestyle Balance (DPP GLB) program with regards to not only weight loss, but program retention and prolonged lifestyle change as well. Ten participants began the program, and seven were retained, attending 79.3% of the conference calls over the 20 wk intervention. Along with the 70% retention, participants rated the program a 6.3±0.3/7 for helplessness and a 6.2±0.6/7 for satisfaction with a significant mean weight loss of 8.86±8.37 kg and significant reduction in BMI in those that completed the intervention. Despite the small sample size making difference detection challenging, the DPP GLB program completers experienced significant weight loss finding the intervention helpful and satisfying.
There is level 1b evidence (from one RCT; Gorgey et al. 2012 and three pre-post studies; Chen et al. 2006, Betts et al. 2017 and Brochetti et al. 2018) that an intervention program combining diet and exercise is effective for reducing weight among overweight persons with SCI.
There is level 1b evidence (from two RCTs; Gorgey et al. 2012 and Li et al. 2018) that interventions targeting just diet and just exercise are both effective for reducing metabolic markers for obesity and associated metabolic diseases like diabetes and heart disease.
There is level 4 evidence (from two pre-post studies; Betts et al. 2017 and Brochetti et al. 2018) that lifestyle interventions that combine diet and exercise and provide accommodation to low-ambulatory participants are effective in participant compliance and retention during and post-intervention.
There is level 5 evidence (from one observational study; Nightingale et al. 2017) that it is important to incorporate strict dietary and exercise guidelines for patients with SCI because of how inconsistent those with SCI are with their daily energy intake and daily energy expenditure.
Strict guidelines for diet and exercise interventions are important for patients with SCI due to the inconsistent nature of their energy balance causing weight gain leading to obesity.
A combined diet and exercise program can help patients reduce weight following SCI without compromising total lean mass and overall health.