Infodoc : Sciences, Techniques et Culture

Due to the increasing prevalence of obesity and the high cost of its treatment different strategies have been proposed to reduce the problem, including high protein (HP) diets which have been shown to improve body composition in animals and humans. However, the mechanisms by which proteins impact on energy homeostasis are not well understood. In our work, we addressed several questions regarding modifications in energy metabolism during an adaptation to an HP diet in rats. We determined changes in gene expression of enzymes involved in energy pathways, accompanied by an investigation of energy expenditure (EE) and substrate utilisation patterns. We also aimed to discover the fate of dietary amino acids by using oral tracers and attempted to assess their participation in energy metabol[...]

Due to the increasing prevalence of obesity and the high cost of its treatment different strategies have been proposed to reduce the problem, including high protein (HP) diets which have been shown to improve body composition in animals and humans. However, the mechanisms by which proteins impact on energy homeostasis are not well understood. In our work, we addressed several questions regarding modifications in energy metabolism during an adaptation to an HP diet in rats. We determined changes in gene expression of enzymes involved in energy pathways, accompanied by an investigation of energy expenditure (EE) and substrate utilisation patterns. We also aimed to discover the fate of dietary amino acids by using oral tracers and attempted to assess their participation in energy metabolism. Additionally, we studied the effect of maternal HP intake on the adiposity of offspring fed a high fat diet. HP intake triggered changes mainly in postprandial macronutrient utilization, enhancing protein oxidation at the expense of carbohydrates, but did not affect any of the components of EE [...]
Face à la prévalence croissante de l'obésité et les dépenses de santé qui en résultent, différentes stratégies ont été proposées, telles que l'ingestion de régimes hyperprotéiques( HP). Plusieurs études montrent qu'ils réduisent l'adiposité chez l'animal et chez l'homme, mais les mécanismes ne sont pas clairement élucidés. Notre objectif était d'étudier les modifications du métabolisme énergétique au cours de l'adaptation à un régime HP chez le rat, en utilisant trois approches : (1) la mesure des flux énergétiques par la calorimétrie indirecte, (2) l'étude du transfert des acides aminés alimentaires dans les voies énergétiques grâce aux isotopes stables, (3) l'évaluation de l'activation/répression des voies énergétiques par mesure de l'expression des gènes. Nous avons également étudié l'effet de l'imprégnation maternelle à un régime hyperprotéique sur l'adiposité de la descendance soumise à un régime gras. L'effet métabolique majeur du régime HP a consisté en des modifications d'utilisation de substrat énergétique en phase postprandiale (les protéines à la place des glucides), sans effet majeur sur les composantes de la dépense énergétique [...]