The lower versus higher carbohydrate groups maintained lower hemoglobin A1c ( 6.6 % [ 95 % CI 6.3-6 .8 % ] vs. 7.2 % [ 6.8-7 .5 % ] or 49 [ 45-51 ] vs. 55 [ 51-58 ] mmol/mol ) at 1 year ( P = 0.008 ) .