Cognitive performance and its relationship with postprandial metabolic changes after ingestion of different macronutrients in the morning

The effect of carbohydrate, protein and fat ingestion on simple as well as complex cognitive functions and the relationship between the respective postprandial metabolic changes and changes in cognitive performance were studied in fifteen healthy male students. Subjects were tested in three sessions, separated by 1 week, for short-term changes in blood variables, indirect calorimetry, subjective performance and different objective performance tasks using a repeated-measures counterbalanced cross-over design. Measurements were made after an overnight fast before and hourly during 3 h after test meal ingestion. Test meals consisted of either pure carbohydrates, protein or fat and were served as isoenergetic (1670 kJ) spoonable creams with similar sensory properties. Most aspects of subjective performance did not differ between test meals. For all objective tasks, however, postprandial cognitive performance was best after fat ingestion concomitant with an almost constant glucose metabolism and constant metabolic activation state measured by glucagon:insulin (G:I). In contrast, carbohydrate as well as protein ingestion resulted in lower overall cognitive performance, both together with partly marked changes (P<0.001) in glucose metabolism and metabolic activation. They also differently affected specific cognitive functions (P<0.05) in relation to their specific effect on metabolism. Carbohydrate ingestion resulted in relatively better short-term memory and accuracy of tasks concomitant with low metabolic activation, whereas protein ingestion resulted in better attention and efficiency of tasks concomitant with higher metabolic activation. Our findings support the concept that good and stable cognitive performance is related to a balanced glucose metabolism and metabolic activation stat

The influence of walking performed immediately before meals with moderate fat content on postprandial lipemia

BACKGROUND: Postprandial lipemia is an independent risk factor for coronary heart disease. Single bouts of moderate exercise may lower this risk, but the minimum duration of moderate intensity exercise that still lowers postprandial lipemia is not known. We, therefore, performed a dose-response study with a normal, daily life setting, to identify the minimum duration of moderate intensity walking that lowers postprandial lipemia in sedentary, healthy young men. METHODS: Sixteen men performed three activity trials (30, 60, or 90 min of treadmill walking at 50% of their individual VO(2)max) and a control trial with no physical activity in a repeated measures crossover design. The subjects walked immediately before ingestion of the first of two mixed meals, which were served 3 h apart. The meals had a moderate fat content (0.5 g per kg body mass and 33% of total energy per meal) and a macronutrient composition corresponding to current recommendations. Each meal provided one third of the subject's estimated daily energy requirement. Venous blood samples were taken in the fasted state, and then hourly for 6 h after the first meal to assess the postprandial phase. Postprandial lipemia (the incremental area under the curve (dAUC) of triacylglycerol) was compared with a mixed model analysis and Tukey's adjustment. RESULTS: Postprandial lipemia (dAUC of triacylglycerol) was, compared to the control trial, +2% (P = 1.00), -14% (P = 0.24), and -15% (P = 0.23) in the 30, 60, and 90 min walking trials, respectively. CONCLUSION: Moderate intensity walking of 60 and 90 min duration slightly, but insignificantly, reduced postprandial lipemia after two mixed meals with moderate fat content in sedentary, healthy young men, compared to inactivity. Therefore, it should be reconsidered if the acute exercise-induced reduction in postprandial lipemia usually observed in studies using high fat meals is of importance in a real, daily life setting

Digestive utilization of novel biodegradable plastic in growing pigs

International audienc

Chromium yeast affects growth performance but not whole carcass composition of growing-finishing pigs

International audienc

Effect of PUFA at sn-2 position in dietary triacylglycerols on fatty acid composition of adipose tissue in growing-finishing pigs

A potential effect of the specific composition of plant oil triacylglycerols, with PUFAs predominantly esterified at the sn-2 position, on the fatty acid composition of adipose tissues of pigs was investigated. Two blends with a ratio of 1/3 and 3/1 of soybean oil and beef tallow were randomised or left unmodified and fed at 4% of a conventional diet to 4 * 12 pigs. The randomisation of fatty acids at sn-1, 2 and 3 positions did not affect the fatty acid composition of pig adipose tissues. It is concluded that the position of PUFA in dietary triacylglycerols is of minor relevance for the composition of depot fat in growing-finishing pig

Effect of PUFA at sn-2 position in dietary triacylglycerols on fatty acid composition of adipose tissue in growing-finishing pigs

A potential effect of the specific composition of plant oil triacylglycerols, with PUFAs predominantly esterified at the sn-2 position, on the fatty acid composition of adipose tissues of pigs was investigated. Two blends with a ratio of 1/3 and 3/1 of soybean oil and beef tallow were randomised or left unmodified and fed at 4% of a conventional diet to 4 * 12 pigs. The randomisation of fatty acids at sn-1, 2 and 3 positions did not affect the fatty acid composition of pig adipose tissues. It is concluded that the position of PUFA in dietary triacylglycerols is of minor relevance for the composition of depot fat in growing-finishing pig