Hydrolyzed Casein Reduces Diet-Induced Obesity in Male C57BL/6J Mice

Abstract

The digestion rate of dietary protein is a regulating factor for postprandial metabolism both in humans and animal models. However, few data exist about the habitual consumption of proteins with different digestion rates with regard to the development of body mass and diet-induced obesity. Here, we used a factorial ANOVA design to investigate the effects of protein form (intact vs. hydrolyzed casein) and protein level (16 vs. 32 energy percent protein) on body mass gain and adiposity in obesity-prone male C57BL/6J mice fed Western diets with 35 energy percent fat. Mice fed the hydrolyzed casein diets had higher spontaneous locomotor activity than mice fed intact casein. During the light phase, mice fed hydrolyzed casein tended (P = 0.08) to have a lower respiratory exchange ratio, indicating lower utilization of carbohydrates as energy substrate relative to those fed intact casein. In further support of less carbohydrate oxidation, plasma concentrations of glucose and those of the glucose metabolite lactate were lower in fed mice that consumed the hydrolyzed compared with the intact casein diet. Concomitantly, the plasma insulin concentration was strongly reduced in fed mice given hydrolyzed casein relative to those given intact casein. The mice fed hydrolyzed casein had greater ex vivo inguinal white adipose tissue non-CO2 β-oxidation capacity along with induced expression of genes involved in mitochondrial fatty acid oxidation and mitochondrial uncoupling. The physiological changes induced by hydrolyzed casein ingestion translated into decreased body and adipose tissue masses. We conclude that chronic consumption of extensively hydrolyzed casein reduces body mass gain and diet-induced obesity in male C57BL/6J mice.

Indomethacin Treatment Prevents High Fat Diet-induced Obesity and Insulin Resistance but Not Glucose Intolerance in C57BL/6J Mice

“…Real-time Quantitative RT-PCR-RNA was extracted from tissue, cDNA was synthesized, and gene expression was measured as described (19).…”

Intake of farmed Atlantic salmon fed soybean oil increases hepatic levels of arachidonic acid-derived oxylipins and ceramides in mice

“…Total RNA was isolated from mouse tissue using Trizol (Invitrogen). Reverse transcription was performed and cDNA was analyzed by qPCR using Light cycler 480 (Roche, Germany) as earlier described [33]. Fatty acid composition was measured in the neutral and phospholipid pools fractionated from liver samples as described earlier [6].…”

A Mixture of Cod and Scallop Protein Reduces Adiposity and Improves Glucose Tolerance in High-Fat Fed Male C57BL/6J Mice

“…Gene expression analysis was performed as described previously [21]. In short, total RNA was isolated from tissue samples with TRIzol Reagent (Invitrogen, Thermo Fisher Scientific, Carlsbad, CA, USA).…”

“…VO 2 and VCO 2 was measured in open-circuit indirect calorimetry cages as described previously [21]. In short, the mice were housed in CaloCages (Phenomaster, TSE Systems), equipped with infrared light-beam frames (ActiMot2).…”

“…From studies in rodents, we know that consumption of hydrolyzed rather than intact proteins reduces body mass gain, adipose tissue mass and hepatic and plasma lipid concentrations [19]–[21]. Moreover, whey ingestion decreased fat mass relative to casein intake in mice [22]–[24], and an intervention study with free-living overweight and obese subjects indicated that intake of whey protein, but not soy protein (both approximately 56 g protein/day for 23 weeks) resulted in a significant reduction in body mass, fat mass and waist circumference, relative to the carbohydrate (maltodextrin) control treatment [25].…”