• Bioactivity in Whey Proteins Influencing Energy Balance

      McAllan, Liam; Cotter, Paul D.; Roche, Helen M.; Korpela, Riitta; Nilaweera, Kanishka (OMICS Publishing Group, 30/03/2012)
      Obesity develops due to energy (food) intake exceeding energy expenditure. Nutrients that reduce the positive energy balance are thus being considered as therapies to combat obesity. Here, we review the literature related to the physiological, cellular and endocrine effects of intake of whey proteins, namely α-lactalbumin, β-lactoglobulin, glycomacropeptide and lactoferrin. Moreover, we discuss how dietary composition and obesity may influence whey protein effects on the above parameters. Evidence suggests that intake of whey proteins causes a decrease in energy intake, increase in energy expenditure, influence insulin sensitivity and glucose homeostasis and alter lipid metabolism in the adipose, liver and muscle. These physiological changes are accompanied by alterations in the plasma levels of energy balance related hormones (cholecystokinin, ghrelin, insulin and glucagon-like peptide-1) and the expression of catabolic and anabolic genes in the above tissue in the direction to cause a negative energy balance.
    • Protein quality and quantity influence the effect of dietary fat on weight gain and tissue partitioning via host-microbiota changes

      Nychyk, Oleksandr; Barton, Wiley; Rudolf, Agata M.; Boscaini, Serena; Walsh, Aaron; Bastiaanssen, Thomaz F.S.; Giblin, Linda; Cormican, Paul; Chen, Liang; Piotrowicz, Yolanda; et al. (Elsevier BV, 2021-05-11)
      We investigated how protein quantity (10%–30%) and quality (casein and whey) interact with dietary fat (20%–55%) to affect metabolic health in adult mice. Although dietary fat was the main driver of body weight gain and individual tissue weight, high (30%) casein intake accentuated and high whey intake reduced the negative metabolic aspects of high fat. Jejunum and liver transcriptomics revealed increased intestinal permeability, low-grade inflammation, altered lipid metabolism, and liver dysfunction in casein-fed but not whey-fed animals. These differential effects were accompanied by altered gut size and microbial functions related to amino acid degradation and lipid metabolism. Fecal microbiota transfer confirmed that the casein microbiota increases and the whey microbiota impedes weight gain. These data show that the effects of dietary fat on weight gain and tissue partitioning are further influenced by the quantity and quality of the associated protein, primarily via effects on the microbiota.