In a randomised design , 15 patients with long-standing T2DM and 15 healthy age - , gender - and BMI-matched control subjects were studied during 75-g oral glucose tolerance test ( OGTT ) and three isocaloric ( 500kcal ) and isovolaemic ( 350ml ) liquid meals : i ) 2.5 g fat , 107g carbohydrate and 13g protein ; ii ) 10g fat , 93g carbohydrate and 11g protein ; and iii ) 40g fat , 32g carbohydrate and 3g protein .