Our data indicate that chronic intake of diets differing in a part of the carbohy-drate source induced substantial weight gain, regardless of the carbohydrate source. Pigs’initial preference and higher motivation was for the GD, compared to SD and FD. Intake ofthe fructose-containing diet for 8 weeks induced a stronger preference for this diet. Our datamay have important implications in terms of impact of prolonged fructose consumption oneating behaviour in humans.