Body Fat-Reducing Effects of Whey Protein Diet in Male Mice

Abstract

This study investigated the mechanism of reducing body fat via whey protein diet. Pregnant mice were fed whey or casein, and their offspring were fed by birth mothers. After weaning at 4 weeks, male pups received the diets administered to their birth mothers (n = 6 per group). At 12 weeks of age, body weight, fat mass, fasting blood glucose (FBG), insulin (IRI), homeostatic model assessment of insulin resistance (HOMA-IR), cholesterol (Cho), triglyceride (TG), the expression levels of lipid metabolism-related genes in liver tissues and metabolomic data of fat tissues were measured and compared between the groups. The birth weights of pups born were similar in the two groups. Compared to the pups in the casein group, at 12 weeks of age, pups in the whey group weighed less, had significantly lower fat mass, HOMA-IR and TG levels (p < 0.01, p = 0.02, p = 0.01, respectively), and significantly higher levels of the antioxidant glutathione and the anti-inflammatory 1-methylnicotinamide in fat tissues (p < 0.01, p = 0.04, respectively). No differences were observed in FBG, IRI, Cho levels (p = 0.75, p = 0.07, p = 0.63, respectively) and expression levels of lipid metabolism-related genes. Whey protein has more antioxidant and anti-inflammatory properties than casein protein, which may be its mechanism for reducing body fat.

Amelioration of Insulin Resistance by Whey Protein in a High-Fat Diet-Induced Pediatric Obesity Male Mouse Model

“…Previously, we speculated that whey protein improves insulin resistance by increasing glutathione in adipocytes and exhibiting an antioxidant effect [ 18 ]. Glutathione is composed of glycine, cysteine, and glutamic acid.…”

“…In a previous study, myo-inositol 1-phosphate levels were found to be elevated by whey protein administration [ 18 ]. Similar results were obtained in a high-fat diet-induced childhood obesity mouse model.…”

“…Fetal administration of whey protein [ 18 ] and administration of whey protein to mice models of high-fat diet-induced childhood obesity led to improvements in fasting blood glucose, insulin resistance, visceral fat loss, and blood lipid profiles. This study suggests that whey protein promotes β-oxidation and enhances anti-inflammatory and antioxidant effects.…”

“…Male mice are known to be more susceptible to the effects of a high-fat diet than female mice [ 21 ]. As male mice were used in our previous experiments [ 18 ], male mice were used in this study.…”

“…Previously, we found that administering whey protein to male mice from the embryonic period had a more pronounced effect on visceral fat reduction and insulin resistance than casein protein. Moreover, this improvement was attributed to the stimulation of β-oxidation by whey protein and its superior anti-inflammatory and antioxidative properties compared to casein protein [ 18 ]. However, few studies have examined the effects of whey protein using pediatric or young-adult obesity models.…”