2.2. Eligibility criteria

Participants were eligible if they: (1) were between the ages of 18 and 65 years; (2) had a traumatic SCI at the cervical, thoracic, or lumbar level (C5–L2) classified as American Spinal Injury Association impairment scale A, B, C, or D; (3) impaired glucose tolerance or insulin resistance; (4) no history of pre‐existing self‐reported type 2 diabetes, renal disease, or pressure injury; (5) were at least 3 years post‐injury (based on data collected from our existing studies, we have observed that glucose intolerance develops as soon as 3 years post‐injury among our participants); (6) had not participated in a weight loss program for the last 6 months; (7) had not habitually consumed a HP diet (~30% energy from dietary protein); (8) had not been on antibiotics for at least 4 weeks before the study, and (9) had not taken medications for weight management, blood glucose, and lipid disorders. Interested participants underwent an oral glucose tolerance test (OGTT) to confirm eligibility (Li et al., 2022). We complied with the American Diabetes Association recommendations (American Diabetes Association, 2017) to identify participants with impaired glucose tolerance (2‐h OGTT serum glucose 140–199 mg/dl). Participants with a Matsuda index below 4.3 were considered insulin resistant (Takahara et al., 2013). Eligible participants were excluded if they developed new health conditions (e.g., pressure injury, kidney disease) that would affect study outcomes or inhibit them from participating or started on new medications. A total of 59 participants underwent the screening procedures, and 33 eligible participants were assigned to either the LC/HP diet group (n = 17) or the control group (n = 16). In the diet group, one participant was excluded due to weight loss before starting the study diet, and five participants discontinued the study diet (three developed new conditions unrelated to the study diet, and two did not like the study diet). Among participants assigned to the control group, one developed a new condition unrelated to the study diet, and one was excluded due to starting new exercise regimens (Figure 1, Consort flow diagram).

CONSORT flowchart