In a randomised , open , crossover , single-centre study ( conducted in Prague , Czech Republic ) , we assigned 54 patients with type 2 diabetes treated with oral hypoglycaemic agents , both men and women , age 30-70 years , BMI 27-50kg / m ( 2 ) and HbA1c 6-11 .8 % ( 42-105mmol / mol ) , to follow two regimens of a hypoenergetic diet , A6 and B2 , each for 12weeks .