Dietary Intake
Table 2 presents dietary data by timepoint. We observed a statistically significant difference in median calorie intake across all three timepoints for the entire cohort (P = 0.013); however, by end of month six, values returned to baseline (P = 0.250). For macronutrients, carbohydrate intake decreased or stabilized by 6-months (P = 0.035, P = 0.064, respectively). Additionally, we observed a corresponding significant increase in protein from study entry to end of month six (P = 0.027) likely owing to the underlying tenets of the low-glycemic diet. Despite increases in calorie intake, we observed a significant reduction in the intake of sugar, a nutrient strongly associated with weight gain, across all three timepoints at the end of induction (P = 0.0051) and 6-months (P = 0.003). We also observed a non-significant increase in fiber. No difference in median GI was observed throughout the intervention (P = 0.920); however, a notable change in energy-adjusted GL was observed (P = 0.030) and there was a trend towards a sustained reduction in energy-adjusted GL from study entry to end of month six (P = 0.053).
Several aspects of diet quality improved over the study period (Supplementary Table #S1). Total vegetable intake increased and remained elevated at the end of month six compared to intakes at study entry (P = 0.033). Intake of added sugars decreased by 54.5% from study entry to end of month six (P = 0.021) and an increased intake of starchy vegetables excluding white potatoes (P = 0.033) was observed. Other notable changes in diet quality across the intervention included increases in total protein foods, total grains, and oils (P = 0.006, P = 0.004, and P = 0.009, respectively), though differences were not sustained by the end of month six (P = 0.130, P = 0.140, and P = 0.280, respectively).