The Experts below are selected from a list of 53766 Experts worldwide ranked by ideXlab platform
Mirella Caporale - One of the best experts on this subject based on the ideXlab platform.
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the role of specific Macronutrient availability in the effect of food restriction on length of lactational diestrus in rats
Physiology & Behavior, 1998Co-Authors: Barbara Woodside, Alfonso Abizaid, Mirella CaporaleAbstract:Abstract WOODSIDE, B., A. ABIZAID AND M. CAPORALE. The role of specific Macronutrient availability in the effect of food restriction on length of lactational diestrus in rats. PHYSIOL BEHAV 64 (3) 409–414, 1998.—In lactating rats, food restriction for the first two weeks postpartum extends the period of lactational diestrus by about 1 week. In these studies we investigated whether this effect results from caloric restriction or the reduced availability of a specific Macronutrient. In Experiment 1 lactating rats nursing litters of eight pups were assigned to one of four conditions: 1) ad lib. fed; 2) protein-restricted; 3) carbohydrate-restricted; and 4) fat-restricted. Animals in all the restricted conditions were given access to 50% of ad lib. intake of the appropriate nutrient for Days 1–14 postpartum and ad lib. access to the other two Macronutrients. In Experiment 2, ad lib. supplementation from one Macronutrient source was provided to lactating rats given restricted access to a composite diet. No differential effect of specific Macronutrient deprivation or supplementation on length of lactational diestrus was observed in these studies. Thus, the results of both studies are consistent with the hypothesis that caloric restriction plays a primary role in inducing the prolongation of lactational diestrus in food-restricted rats.
Linda Giblin - One of the best experts on this subject based on the ideXlab platform.
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physiological gut oxygenation alters glp 1 secretion from the enteroendocrine cell line stc 1
Molecular Nutrition & Food Research, 2018Co-Authors: Alina Kondrashina, Dmitri B Papkovsky, Linda GiblinAbstract:SCOPE: Enteroendocrine cell lines are routinely assayed in simple buffers at ≈20% oxygen to screen foods for bioactives that boost satiety hormone levels. However, in vivo, enteroendocrine cells are exposed to different phases of food digestion and function at low oxygen concentration, ranging from 7.5% in the stomach to 0.5% in the colon-rectal junction. METHODS AND RESULTS: The objective of this study is to investigate the effect of physiologically relevant O2 concentrations of the gut on the production and secretion of the satiety hormone, glucagon-like peptide 1 (GLP-1), from the murine enteroendocrine cell line, secretin tumor cell line (STC-1), in response to dairy Macronutrients as they transit the gut. GLP-1 exocytosis from STC-1 cells is influenced by both oxygen concentration and by individual Macronutrients. At low oxygen, STC-1 cell viability is significantly improved for all Macronutrient stimulations and cyclic adenosine monophosphate levels are dampened. GLP-1 secretion from STC-1 cells is influenced by both the phase of yogurt digestion and corresponding O2 concentration. Atmospheric oxygen at 4.5% combined with upper gastric digesta, which simulates ileum conditions, yields the highest GLP-1 response. CONCLUSION: This demonstrates the importance of considering physiological oxygen levels and food digestion along gastrointestinal tract for reliable in vitro analysis of gut hormone secretion.
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Physiological Gut Oxygenation Alters GLP‐1 Secretion from the Enteroendocrine Cell Line STC‐1
Molecular Nutrition & Food Research, 2018Co-Authors: Alina Kondrashina, Dmitri B Papkovsky, Linda GiblinAbstract:SCOPE: Enteroendocrine cell lines are routinely assayed in simple buffers at ≈20% oxygen to screen foods for bioactives that boost satiety hormone levels. However, in vivo, enteroendocrine cells are exposed to different phases of food digestion and function at low oxygen concentration, ranging from 7.5% in the stomach to 0.5% in the colon-rectal junction. METHODS AND RESULTS: The objective of this study is to investigate the effect of physiologically relevant O2 concentrations of the gut on the production and secretion of the satiety hormone, glucagon-like peptide 1 (GLP-1), from the murine enteroendocrine cell line, secretin tumor cell line (STC-1), in response to dairy Macronutrients as they transit the gut. GLP-1 exocytosis from STC-1 cells is influenced by both oxygen concentration and by individual Macronutrients. At low oxygen, STC-1 cell viability is significantly improved for all Macronutrient stimulations and cyclic adenosine monophosphate levels are dampened. GLP-1 secretion from STC-1 cells is influenced by both the phase of yogurt digestion and corresponding O2 concentration. Atmospheric oxygen at 4.5% combined with upper gastric digesta, which simulates ileum conditions, yields the highest GLP-1 response. CONCLUSION: This demonstrates the importance of considering physiological oxygen levels and food digestion along gastrointestinal tract for reliable in vitro analysis of gut hormone secretion.
Stephen J. Simpson - One of the best experts on this subject based on the ideXlab platform.
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Macronutrients and caloric intake in health and longevity
Journal of Endocrinology, 2015Co-Authors: Samantha M. Solon-biet, David Raubenheimer, David G. Le Couteur, Sarah J. Mitchell, Rafael De Cabo, Stephen J. SimpsonAbstract:Both lifespan and healthspan are influenced by nutrition, with nutritional interventions proving to be robust across a wide range of species. However, the relationship between nutrition, health and aging is still not fully understood. Caloric restriction is the most studied dietary intervention known to extend life in many organisms, but recently the balance of Macronutrients has been shown to play a critical role. In this review, we discuss the current understanding regarding the impact of calories and Macronutrient balance in mammalian health and longevity and highlight the key nutrient-sensing pathways that mediate the effects of nutrition on health and ageing.
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geometric analysis of Macronutrient selection in breeds of the domestic dog canis lupus familiaris
Behavioral Ecology, 2013Co-Authors: Adrian K Hewsonhughes, Stephen J. Simpson, Victoria L Hewsonhughes, Alison Colyer, Andrew T Miller, Scott J Mcgrane, Simon Reginald Hall, Richard F Butterwick, David RaubenheimerAbstract:Although many herbivores and omnivores have been shown to balance their intake of Macronutrients when faced with nutritionally variable foods, study of this ability has been relatively neglected in carnivores, largely on the assumption that prey are less variable in nutrient composition than the foods of herbivores and omnivores and such mechanisms therefore unnecessary. We performed diet selection studies in 5 breeds of adult dog (Canis lupus familiaris) to determine whether these domesticated carnivores regulate Macronutrient intake. Using nutritional geometry, we show that the Macronutrient content of the diet was regulated to a protein:fat:carbohydrate ratio of approximately 30%:63%:7% by energy, a value that was remarkably similar across breeds. These values, which the analysis suggests are dietary target values, are based on intakes of dogs with prior experience of the respective experimental food combinations. On initial exposure to the diets (i.e., when naive), the same dogs self-selected a diet that was marginally but significantly lower in fat, suggesting that learning played a role in Macronutrient regulation. In contrast with the tight regulation of Macronutrient ratios, the total amount of food and energy eaten was far higher than expected based on calculated maintenance energy requirements. We interpret these results in relation to the evolutionary history of domestic dogs and compare them to equivalent studies on domestic cats.
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geometric analysis of Macronutrient selection in the adult domestic cat felis catus
The Journal of Experimental Biology, 2011Co-Authors: Adrian K Hewsonhughes, Stephen J. Simpson, Victoria L Hewsonhughes, Andrew T Miller, Simon Reginald Hall, David RaubenheimerAbstract:We report feeding studies on adult domestic cats designed to disentangle the complex interactions among dietary protein, fat and carbohydrate in the control of intake. Using geometric techniques that combine mixture triangles and intake plots from the geometric framework, we: (1) demonstrate that cats balance their Macronutrient intake, (2) estimate the composition of the target balance and (3) reveal the priorities given to different Macronutrients under dietary conditions where the target is unachievable. Our analysis indicates that cats have a ceiling for carbohydrate intake, which limits ingestion and constrains them to deficits in protein and fat intake (relative to their target) on high-carbohydrate foods. Finally, we reanalyse data from a previous experiment that claimed that kittens failed to regulate protein intake, and show that, in fact, they did. These results not only add to the growing appreciation that carnivores, like herbivores and omnivores, regulate Macronutrient intake, they also have important implications for designing feeding regimens for companion animals.
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Macronutrient balance mediates trade offs between immune function and life history traits
Functional Ecology, 2011Co-Authors: Sheena C Cotter, David Raubenheimer, Stephen J. Simpson, Kenneth WilsonAbstract:1. Diet and health are intimately linked and recent studies have found that caloric restriction can affect immune function. However, when given a choice between diets that differ in their Macronutrient composition, pathogen-infected individuals can select a diet that improves their survival, suggesting that the nutritional composition of the diet, as well as its calorie content, can play a role in defence against disease. Moreover, as individuals change their diet when infected, it suggests that a diet that is optimal for growth is not optimal for immunity, leading to trade-offs. 2. Currently, our knowledge of the effects of diet on immunity is limited because previous experiments have manipulated either single nutrients or the calorie content of the diet without considering their interactive effects. By simultaneously manipulating both the diet composition (quality) and its caloric density (quantity), in both naive and immune-challenged insects, we asked how do diet quality and quantity influence an individual's ability to mount an immune response? And to what extent are allocation trade-offs driven by quantity- versus quality-based constraints? 3. We restricted individuals to 20 diets varying in their protein and carbohydrate content and used 3D response surfaces to visualize dietary effects on larval growth and immune traits. Our results show that both constitutive and induced immune responses are not limited by the total quantity of nutrients consumed, but rather different traits respond differently to variation in the ratios of Macronutrients (diet quality), and peak in different regions of Macronutrient space. The preferred dietary composition therefore represents a compromise between the nutritional requirements of growth and immune responses. We also show that a non-pathogenic immune challenge does not affect diet choice, rather immune-challenged insects modify their allocation of nutrients to improve their immune response. 4. Our results indicate that immune traits are affected by the Macronutrient content of the diet and that no diet can simultaneously optimize all components of the immune system. To date the emphasis has been on the effects of micronutrients in improving immunity, our findings indicate that this must be widened to include the neglected impact of Macronutrients on defence against disease.
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A framework for the study of Macronutrient intake in fish
Aquaculture Research, 2001Co-Authors: Stephen J. Simpson, David RaubenheimerAbstract:A good understanding of the capabilities of commercially reared fish species to regulate intake of specific Macronutrients has potential economic, welfare and environmental benefits. We present a conceptual and experimental framework for studying Macronutrient intake in fish. This ‘geometric’ approach addresses the multidimensional and interactive nature of nutrition. It was developed from work on insect herbivores and has successfully been applied to mammals and birds. The various components of the framework are introduced in simple outlines, and key experimental designs are described for assessing whether or not fish specifically regulate their intake of Macronutrients, how they balance over-ingesting some nutrients against undereating others when provided with suboptimal diets, and how they regulate growth post-ingestively.
David Raubenheimer - One of the best experts on this subject based on the ideXlab platform.
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The Effects of Dietary Macronutrient Balance on Skin Structure in Aging Male and Female Mice.
PLOS ONE, 2016Co-Authors: Samantha M. Solon-biet, Aisling C. Mcmahon, Kari Ruohonen, David Raubenheimer, J. William O. Ballard, David G. Le Couteur, Caroline Nicholls, Zhe Li, Peter K.m. MaitzAbstract:Nutrition influences skin structure; however, a systematic investigation into how energy and Macronutrients (protein, carbohydrate and fat) affects the skin has yet to be conducted. We evaluated the associations between Macronutrients, energy intake and skin structure in mice fed 25 experimental diets and a control diet for 15 months using the Geometric Framework, a novel method of nutritional analysis. Skin structure was associated with the ratio of dietary Macronutrients eaten, not energy intake, and the nature of the effect differed between the sexes. In males, skin structure was primarily associated with protein intake, whereas in females carbohydrate intake was the primary correlate. In both sexes, the dermis and subcutaneous fat thicknesses were inversely proportional. Subcutaneous fat thickness varied positively with fat intake, due to enlarged adipocytes rather than increased adipocyte number. We therefore demonstrated clear interactions between skin structure and Macronutrient intakes, with the associations being sex-specific and dependent on dietary Macronutrient balance.
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Macronutrients and caloric intake in health and longevity
Journal of Endocrinology, 2015Co-Authors: Samantha M. Solon-biet, David Raubenheimer, David G. Le Couteur, Sarah J. Mitchell, Rafael De Cabo, Stephen J. SimpsonAbstract:Both lifespan and healthspan are influenced by nutrition, with nutritional interventions proving to be robust across a wide range of species. However, the relationship between nutrition, health and aging is still not fully understood. Caloric restriction is the most studied dietary intervention known to extend life in many organisms, but recently the balance of Macronutrients has been shown to play a critical role. In this review, we discuss the current understanding regarding the impact of calories and Macronutrient balance in mammalian health and longevity and highlight the key nutrient-sensing pathways that mediate the effects of nutrition on health and ageing.
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geometric analysis of Macronutrient selection in breeds of the domestic dog canis lupus familiaris
Behavioral Ecology, 2013Co-Authors: Adrian K Hewsonhughes, Stephen J. Simpson, Victoria L Hewsonhughes, Alison Colyer, Andrew T Miller, Scott J Mcgrane, Simon Reginald Hall, Richard F Butterwick, David RaubenheimerAbstract:Although many herbivores and omnivores have been shown to balance their intake of Macronutrients when faced with nutritionally variable foods, study of this ability has been relatively neglected in carnivores, largely on the assumption that prey are less variable in nutrient composition than the foods of herbivores and omnivores and such mechanisms therefore unnecessary. We performed diet selection studies in 5 breeds of adult dog (Canis lupus familiaris) to determine whether these domesticated carnivores regulate Macronutrient intake. Using nutritional geometry, we show that the Macronutrient content of the diet was regulated to a protein:fat:carbohydrate ratio of approximately 30%:63%:7% by energy, a value that was remarkably similar across breeds. These values, which the analysis suggests are dietary target values, are based on intakes of dogs with prior experience of the respective experimental food combinations. On initial exposure to the diets (i.e., when naive), the same dogs self-selected a diet that was marginally but significantly lower in fat, suggesting that learning played a role in Macronutrient regulation. In contrast with the tight regulation of Macronutrient ratios, the total amount of food and energy eaten was far higher than expected based on calculated maintenance energy requirements. We interpret these results in relation to the evolutionary history of domestic dogs and compare them to equivalent studies on domestic cats.
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geometric analysis of Macronutrient selection in the adult domestic cat felis catus
The Journal of Experimental Biology, 2011Co-Authors: Adrian K Hewsonhughes, Stephen J. Simpson, Victoria L Hewsonhughes, Andrew T Miller, Simon Reginald Hall, David RaubenheimerAbstract:We report feeding studies on adult domestic cats designed to disentangle the complex interactions among dietary protein, fat and carbohydrate in the control of intake. Using geometric techniques that combine mixture triangles and intake plots from the geometric framework, we: (1) demonstrate that cats balance their Macronutrient intake, (2) estimate the composition of the target balance and (3) reveal the priorities given to different Macronutrients under dietary conditions where the target is unachievable. Our analysis indicates that cats have a ceiling for carbohydrate intake, which limits ingestion and constrains them to deficits in protein and fat intake (relative to their target) on high-carbohydrate foods. Finally, we reanalyse data from a previous experiment that claimed that kittens failed to regulate protein intake, and show that, in fact, they did. These results not only add to the growing appreciation that carnivores, like herbivores and omnivores, regulate Macronutrient intake, they also have important implications for designing feeding regimens for companion animals.
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Macronutrient balance mediates trade offs between immune function and life history traits
Functional Ecology, 2011Co-Authors: Sheena C Cotter, David Raubenheimer, Stephen J. Simpson, Kenneth WilsonAbstract:1. Diet and health are intimately linked and recent studies have found that caloric restriction can affect immune function. However, when given a choice between diets that differ in their Macronutrient composition, pathogen-infected individuals can select a diet that improves their survival, suggesting that the nutritional composition of the diet, as well as its calorie content, can play a role in defence against disease. Moreover, as individuals change their diet when infected, it suggests that a diet that is optimal for growth is not optimal for immunity, leading to trade-offs. 2. Currently, our knowledge of the effects of diet on immunity is limited because previous experiments have manipulated either single nutrients or the calorie content of the diet without considering their interactive effects. By simultaneously manipulating both the diet composition (quality) and its caloric density (quantity), in both naive and immune-challenged insects, we asked how do diet quality and quantity influence an individual's ability to mount an immune response? And to what extent are allocation trade-offs driven by quantity- versus quality-based constraints? 3. We restricted individuals to 20 diets varying in their protein and carbohydrate content and used 3D response surfaces to visualize dietary effects on larval growth and immune traits. Our results show that both constitutive and induced immune responses are not limited by the total quantity of nutrients consumed, but rather different traits respond differently to variation in the ratios of Macronutrients (diet quality), and peak in different regions of Macronutrient space. The preferred dietary composition therefore represents a compromise between the nutritional requirements of growth and immune responses. We also show that a non-pathogenic immune challenge does not affect diet choice, rather immune-challenged insects modify their allocation of nutrients to improve their immune response. 4. Our results indicate that immune traits are affected by the Macronutrient content of the diet and that no diet can simultaneously optimize all components of the immune system. To date the emphasis has been on the effects of micronutrients in improving immunity, our findings indicate that this must be widened to include the neglected impact of Macronutrients on defence against disease.
Jayne V Woodside - One of the best experts on this subject based on the ideXlab platform.
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the effect of increasing fruit and vegetable consumption on overall diet a systematic review and meta analysis
Critical Reviews in Food Science and Nutrition, 2016Co-Authors: Sharon L Fulton, Michelle C Mckinley, Ian S Young, Christopher Cardwell, Jayne V WoodsideAbstract:Increasing fruit and vegetable (FV) consumption is associated with reduced risk of major diseases. However, it is unclear if health benefits are related to increased micronutrient intake or to improvements in overall diet profile.This review aimed to assess if increasing FV consumption had an impact on diet profile. In the systematic review, 12 studies revealed increases in micronutrient intakes, whilst the meta-analysis confirmed Macronutrient findings from the systematic review showing no significant difference between the intervention and control groups in energy (kcals) in seven studies (mean difference = 1 kcals [95% CI = −115, 117]; p = 0.98), significant decreases in total fat (% energy) in five studies (Mean difference = −4% [95% CI = −5, −3]; p = < 0.00001) and significant increases in fiber in six studies (Mean difference = 5.36 g [95% CI = 4, 7]; p = < 0.00001) and total carbohydrate (% energy) in four studies (Mean = 4% [95% CI= 2, 5]; p = < 0.00001).In conclusion, results indicate that increa...
