After an 8-week low-calorie diet ( LCD ) , 256 adults ( body mass index > 27kgm ( - ) ( 2 ) ) were randomized to five ad libitum diets for 12 months : high P/LGI ( HP/LGI ) , HP/high GI ( HP/HGI ) , low P/LGI ( LP/LGI ) , LP/HGI and a control diet .