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Macronutrient Composition (macronutrient + composition)
Selected AbstractsDifferential Effects of Restricted Versus Unlimited High-Fat Feeding in Rats on Fat Mass, Plasma Hormones and Brain Appetite RegulatorsJOURNAL OF NEUROENDOCRINOLOGY, Issue 7 2009T. Shiraev The rapid rise in obesity has been linked to altered food consumption patterns. There is increasing evidence that, in addition to total energy intake, the macronutrient composition of the diet may influence the development of obesity. The present study aimed to examine the impact of high dietary fat content, under both isocaloric and hypercaloric conditions, compared with a low fat diet, on adiposity, glucose and lipid metabolism, and brain appetite regulators in rats. Male Sprague,Dawley rats were exposed to one of three diets: control (14% fat), ad lib high-fat palatable (HFD, 35% fat) or high-fat palatable restricted (HFD-R, matched to the energy intake of control) and were killed in the fasting state 11 weeks later. Body weight was increased by 28% in unrestricted HFD fed rats, with an almost tripling of caloric intake and fat mass (P < 0.001) and double the plasma triglycerides of controls. Glucose intolerance and increased insulin levels were observed. HFD-R animals calorie matched to control had double their fat mass, plasma insulin and triglycerides (P < 0.05). Only ad lib consumption of the HFD increased the hypothalamic mRNA expression of the appetite-regulating peptides, neuropeptide Y and pro-opiomelanocortin. Although restricted consumption of palatable HFD had no significant impact on hypothalamic appetite regulators or body weight, it increased adiposity and circulating triglycerides, suggesting that the proportion of dietary fat, independent of caloric intake, affects fat deposition and the metabolic profile. [source] Effects of duodenal fat, protein or mixed-nutrient infusions on epigastric sensations during sustained gastric distension in healthy humansNEUROGASTROENTEROLOGY & MOTILITY, Issue 2 2002C. FEINLE Duodenal fat modulates sensory and motor responses to gastric distension and raises plasma cholecystokinin compared with glucose. The effects of protein (also releasing cholecystokinin), or mixed nutrients (with a balanced macronutrient composition), on gastrointestinal sensations in relation to gastric relaxation and plasma cholecystokinin concentrations are not known. The aim of this study was therefore to compare the effects of duodenal infusion of fat, protein or mixed nutrients during sustained gastric distension (mimicking the intragastric presence of food) on these parameters. In 10 healthy subjects, gastric distension to fullness was maintained for 90 min, while gastric volume, sensations and plasma cholecystokinin were monitored during duodenal infusion of isotonic saline or nutrients (2 kcal min,1). During saline infusion, all parameters remained unchanged for 90 min. Initially, only lipid increased plasma cholecystokinin, gastric volume and scores for sensations. Cholecystokinin and gastric volume responses to protein and mixed nutrients were delayed and not associated with significant changes in sensations. In conclusion, the intensity of gastrointestinal sensations is related to, but not entirely explained by, the magnitude in intragastric volume and plasma cholecystokinin changes. Our results offer new insights into the role of dietary nutrient composition in gastrointestinal sensations, and may have implications for the dietary management of digestive symptoms. [source] Dietary Composition and Weight Loss: Can We Individualize Dietary Prescriptions According to Insulin Sensitivity or Secretion Status?NUTRITION REVIEWS, Issue 10 2006Anastassios G. Pittas MD There is considerable uncertainty over whether any one dietary pattern broadly facilitates weight loss or maintenance of weight loss, and current dietary guidelines recommend a spectrum of dietary composition for the general population. However, emerging evidence suggests that specific dietary compositions may work better for identifiable groups of overweight/obese individuals based on their individual metabolic status. In particular, characteristics of insulin dynamics, such as insulin sensitivity or insulin secretion status, may interact with diets that vary in macronutrient composition to influence the weight loss achieved with a hypocaloric diet. [source] Milk composition of captive tufted capuchins (Cebus apella)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 1 2010Lauren A. Milligan Abstract Little is known about the milk composition of nonhuman primates, and it has never been examined in capuchin monkeys (genus Cebus). This article reports on the macronutrient milk composition (fat, crude protein (CP), lactose, dry matter (DM), and total gross energy (GE)) of captive housed tufted capuchins (Cebus apella) (n=8). C. apella milk averaged 5.22% fat, 2.40% CP, 6.94% lactose, 16.48% DM, and 0.89 kcal/g. Fat was the most variable macronutrient and was significantly higher in samples collected after 2 months of lactation. To explore the adaptive significance of C. apella milk composition, results were compared with data on milk composition from a closely related cebid, Saimiri boliviensis boliviensis, and another large-brained anthropoid, Homo sapiens. C. apella milk was only significantly different from Saimiri milk in CP and the proportion of energy from CP. Compared with human milk, C. apella milk was lower in lactose but higher in fat, CP, DM, GE, and the proportion of energy from CP. Results from this small dataset suggest that among anthropoid primates, the macronutrient composition of milk is influenced by phylogeny, may vary relative to infant growth rates, but may not be related in any direct way to relative brain size. Am. J. Primatol. 72:81,86, 2010. © 2009 Wiley-Liss, Inc. [source] A multivariate approach to optimization of macronutrient composition in weaning diets for cod (Gadus morhua)AQUACULTURE NUTRITION, Issue 1 2006K. HAMRE Abstract Atlantic cod, initial weight 0.26 g, were fed diets varying in added protein from 530 to 830 g kg,1, lipid from 50 to 300 g kg,1 and carbohydrate from 0 to 150 g kg,1 of dry weight, according to a three-component mixture design. Analysed values of protein and lipid were 500,770 g kg,1 and 30,270 g kg,1, respectively. Analysed carbohydrate levels were as added. Increasing levels of both lipid and carbohydrate had a positive effect on fish growth (P < 10,3), whereas protein levels above 600 g kg,1 gave a reduction in growth (P < 10,4). The effects on growth were evident in fish less than 4 g, whereas fish growth between 4 and 6 g was unaffected by the dietary variation. It is hypothesized that the reduction in growth at high protein levels in fish of less than 4 g could be owing to incomplete utilization of protein, as the stomach of cod is not fully developed before the fish is approximately 1 g. Mortality and cannibalism were high in fish less than 4 g but low when the fish grew from 4 to 6 g. There was a significant decrease in cannibalism with increasing dietary lipid during the first half of the experiment (P < 0.05) and cannibalism was consistently high in fish fed less than 150 g kg,1 lipid. The lipid level in whole fish increased with increasing dietary levels of lipid (P < 10,6) and carbohydrate (P < 10,4), whereas the liver lipid level increased with increasing dietary lipid up to 200 g kg,1 (P < 10,6) and decreased thereafter (P < 10,4). Whole body glycogen increased slightly with increasing levels of dietary carbohydrate (P < 0.05) and was not affected by the other dietary variables. Liver glycogen increased in response to increasing dietary carbohydrate (P < 10,5) and decreasing levels of dietary lipid (P < 10,5). An abrupt increase in liver glycogen was seen with the reduction in dietary lipid from 100 to 50 g kg,1. The hepatosomatic index increased in response to both dietary lipid and carbohydrate (P < 10,6). It is concluded that the protein requirement of young cod is less than 500 g kg,1 of dry diet. Fish of less than 4 g should not be given more than 620 g kg,1 protein and should be supplemented with 150,200 g kg,1 lipid. Carbohydrate up to 150 g kg,1 of dry diet promoted growth and did not seem to affect the fish negatively. Fish above 4 g can be given diets varying in protein and carbohydrate over the wide range of concentrations used in the present study, but lipid supplementation should be restricted to between 100 and 200 g kg,1. [source] | ||||||||||