High intake of milk, but not meat, increases insulin and insulin resistance in 8 year old boys

Department of Human Nutrition and Centre for Advanced Food Studies, The Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
European Journal of Clinical Nutrition (Impact Factor: 2.71). 04/2005; 59(3):393-8. DOI: 10.1038/sj.ejcn.1602086
Source: PubMed


Our objective was to examine if a high animal protein intake from milk or meat increased s-insulin and insulin resistance in healthy, prepubertal children. A high animal protein intake results in higher serum branched chain amino acids (BCAA; leucine, isoleucine and valine) concentrations, which are suggested to stimulate insulin secretion. Furthermore, milk possesses some postprandial insulinotrophic effect that is not related to its carbohydrate content.
A total of 24 8-y-old boys were asked to take 53 g protein as milk or meat daily. At baseline and after 7 days, diet was registered, and insulin, glucose, and amino acids were determined. Insulin resistance and beta cell function were calculated with the homeostasis model assessment.
Protein intake increased by 61 and 54% in the milk- and meat-group, respectively. In the milk-group, fasting s-insulin concentrations doubled, which caused the insulin resistance to increase similarly. In the meat-group, there was no increase in insulin and insulin resistance. As the BCAAs increased similarly in both groups, stimulation of insulin secretion through BCAAs is not supported.
Our results indicate that a short-term high milk, but not meat, intake increased insulin secretion and resistance. The long-term consequences of this are unknown. The effect of high protein intakes from different sources on glucose-insulin metabolism needs further studying.

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Available from: Camilla Hoppe
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    • "These data support our recent proposal that milk functions as an endocrine signaling system promoting mTORC1 signaling driving anabolic pathways for postnatal growth [3]. Adipogenic and insulin resistance inducing effects of whole milk consumption are compatible with recent observations in human subjects, who have been supplemented with milk protein fractions [4] [5]. Western diet, characterized by persistent milk and dairy protein consumption, may thus promote mTORC1-driven diseases of civilization [6]. "

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