Table 2:
Three-Month Pre-COVID-19 Diet Period 1 Intervention Effects—Overall and by Randomized Diet Assignment
| Primary Outcomes | |||||
|---|---|---|---|---|---|
| All (n=38) | Diet Assignment (Low carbohydrate as P-value Reference) | ||||
| Low carb (n=16) | Look AHEAD (n=12) | Mediterranean (n=10) | p-value† | ||
| Weight (kg) | |||||
| Baseline | 87.4 ± 12.9 | 87.2 ± 10.8 | 90.5 ± 16.5 | 84.1 ± 11.5 | 0.53 |
| ~3-months | 85.4 ± 12.7 | 84.8 ± 11.8 | 89.2 ± 15.5 | 81.7 ± 10.2 | 0.39 |
| ~3-month change | −2.0 (−3.0, −1.1), p<0.0001 | −2.4 (−3.9, −0.93) | −1.3 (−3.4, 0.82) | −2.4 (−4.3, −0.52) | 0.55 |
| HbA1c (%) | |||||
| Baseline | 7.9 ± 1.5 | 7.3 ± 1.6 | 8.3 ± 1.3 | 8.3 ± 1.4 | 0.14 |
| ~3-months | 7.8 ± 1.5 | 7.3 ± 1.6 | 7.7 ± 1.0 | 8.6 ± 1.7 | 0.09 |
| ~3-month percentage point change | −0.13 (−0.39, 0.12), p=0.29 | −0.04 (−0.25, 0.17) | −0.65 (−1.1, −0.18), p=0.027 | 0.34 (−0.34, 1.0), p=0.18 | 0.006 |
| HbA1c (mmol/mol) | |||||
| Baseline | 63 ± 16.4 | 56 ± 17.5 | 67 ± 14.2 | 67 ± 15.3 | 0.14 |
| ~3-months | 62 ± 16.4 | 56 ± 17.5 | 61 ± 10.9 | 70 ± 18.6 | 0.09 |
| ~3-month change | −1.4 (−4.3, 1.3), p=0.29 | −0.4 (−2.7, 1.9) | −7.1 (−12.0, −2.0), p=0.027 | 3.7 (−3.7, 10.9), p=0.18 | 0.006 |
| All (n=28) | Low carb (n=12) | Look AHEAD (n=8) | Mediterranean (n=8) | p-value† | |
| % Time below range (<70 mg/dL) | |||||
| Baseline | 5.0 (1.9, 9.8) | 6.0 (2.9, 12.3) | 4.3 (1.6, 8.2) | 3.5 (0.73, 6.9) | 0.29 |
| ~3-months | 5.3 (2.2, 9.8) | 9.1 (4.5, 11.4) | 3.1 (1.5, 7.6) | 3.3 (0.43, 6.5) | 0.04 |
| ~3-month percentage point change | 0.42 (−1.7, 2.6), p=0.69 | 1.3 (−2.1, 4.6) | 0.23 (−3.9, 4.4) | −0.64 (4.8, 3.5) | 0.76 |
| Secondary outcomes | |||||
| All (n=38) | Low carb (n=16) | Look AHEAD (n=12) | Mediterranean (n=10) | p-value† | |
| Body fat (%) | |||||
| Baseline | 42.2 (34.7, 45.2) | 42.1 (29.4, 45.2) | 42.8 (37.7, 45.3) | 40.7 (34.8, 45.2) | 0.83 |
| ~3-months | 40.6 (33.8, 44.7) | 40.5 (27.9, 44.2) | 43.7 (37.3, 45.5) | 40.1 (35.9, 43.2) | 0.52 |
| ~3-month percentage point change | −0.53 (−1.0, −0.03), p=0.04 | −0.87 (−1.7, −0.05) | −0.058 (−0.83, 0.72) | −0.57 (−1.9, 0.75) | 0.39 |
| Body fat (kg) | |||||
| Baseline | 34.4 ± 9.8 | 32.6 ± 10.6 | 37.1 ± 9.6 | 34.1 ± 8.8 | 0.49 |
| ~3-months | 33.3 ± 10.0 | 31.0 ± 11.2 | 36.7 ± 9.9 | 32.8 ± 7.6 | 0.33 |
| ~3-month change | −1.1 (−1.9, −0.40), p=0.003 | −1.6 (−2.8, −0.38) | −0.36 (−1.6, 0.83), p=0.76 | −1.3 (−3.1, 0.44), p=0.15 | 0.34 |
| All (n=28) | Low carb (n=12) | Look AHEAD (n=8) | Mediterranean (n=8) | p-value† | |
| % Time in range (70–180 mg/dL) | |||||
| Baseline | 52.6 ± 26.0 | 55.8 ± 25.5 | 58.2 ± 24.2 | 42.3 ± 28.8 | 0.42 |
| ~3-months | 54.8 ± 22.9 | 58.0 ± 24.8 | 63.6 ± 17.0 | 41.4 ± 21.1 | 0.12 |
| ~3-month percentage point change | 2.2 (−3.4, 7.8), p=0.43 | 2.1 (−6.7, 11.0) | 5.4 (−8.7, 19.6) | −0.88 (−12.6, 10.8) | 0.70 |
| % Time below range (<54 mg/dL) | |||||
| Baseline | 0.82 (0.19, 2.8) | 1.6 (0.73, 3.1) | 0.21 (0.04, 1.9) | 0.71 (0.0, 2.9) | 0.63 |
| ~3-months | 1.2 (0.19, 3.3) | 1.6 (0.63, 3.8) | 0.37 (0.0, 3.7) | 1.2 (0.0, 2.9) | 0.45 |
| ~3-month percentage point change | 0.00 (−1.2, 1.5), p=0.68 | 0.67 (−1.1, 2.5) | 0.57 (−1.6, 2.8) | 0.18 (−2.0, 2.4) | 0.93 |
| Additional CGM indices | |||||
| % Time above range (181–250 mg/dL) | |||||
| Baseline | 19.7 ± 8.7 | 18.7 ± 11.5 | 19.0 ± 5.2 | 21.8 ± 7.3 | 0.73 |
| ~3-months | 21.3 ± 12.0 | 18.0 ± 11.8 | 17.1 ± 8.2 | 30.3 ± 11.7 | 0.03 |
| ~3-month percentage point change | 0.32 (−2.9, 6.5), p=0.61 | −0.53 (−7.4, 5.9) | −1.1 (−2.9, 0.68) | 6.6 (1.2, 13.8) | 0.07 |
| % Time above range (>250 mg/dL) | |||||
| Baseline | 9.0 (2.2, 4.3) | 5.2 (0.19, 38.9) | 8.3 (2.5, 19.7) | 29.9 (4.7, 51.6) | 0.28 |
| ~3-months | 9.8 (2.5, 27.5) | 7.1 (0.57, 18.9) | 8.5 (4.3, 23.5) | 22.8 (8.1, 35.5) | 0.26 |
| ~3-month percentage point change | −4.2 (−11.5, 3.2), p=0.25 | −2.7 (−12.6, 7.2) | −3.6 (−18.1, 10.9) | −7.0 (−28.9, 14.9) | 0.89 |
| CV (%) | |||||
| Baseline | 37.3 ± 6.5 | 37.2 ± 6.8 | 38.2 ± 6.0 | 36.4 ± 7.3 | 0.69 |
| ~3-months | 38.1 ± 6.9 | 37.6 ± 8.2 | 40.4 ± 6.6 | 36.4 ± 4.9 | 0.50 |
| ~3-month change | 0.46 (−2.4, 3.1), p=0.67 | 0.27 (−1.9, 3.2) | −0.14 (−2.8, 5.5) | 1.8 (−3.0, 2.3) | 0.99 |
Baseline values are mean ±SD or median (IQR). Change values are mean (95% confidence interval) or median (IQR). Within-group p-values are from paired t tests for normally distributed variables or the Wilcoxon signed rank test for non-normally distributed variables.
†
P-values for diet difference in the rightmost column were calculated using ANOVA for normally distributed variables or the Kruskal Wallis test for non-normally distributed variables.
Abbreviations: CV—coefficient of variation; Low carb—Low carbohydrate; mg/dL—milligrams per deciliter; HbA1c—hemoglobin A1c.