In the original study
Among the participants with diabetes, the proportion of glycated haemoglobin at 24 months decreased by 0.4±1.3% in the low-fat group, 0.5±1.1% in the Mediterranean-diet group, and 0.9±0.8% in the low-carbohydrate group. The changes were significant (P<0.05) only in the low-carbohydrate group (P=0.45 for the comparison among groups).
A four year follow up concluded
…a 2-year workplace intervention trial involving healthy dietary changes had long-lasting, favourable post-intervention effects, particularly among participants receiving the Mediterranean and low-carbohydrate diets, despite a partial regain of weight.
Liz & Glyn Wainwright 