A high-whey-protein diet reduces body weight gain and alters insulin sensitivity relative to red meat in wistar rats.
A high-protein diet can reduce body weight and increase insulin sensitivity, but whether the type of dietary protein affects these outcomes is unknown. We hypothesized that feeding insulin-resistant rats a high-protein diet (32%) containing whey protein concentrate (WPC) would reduce body weight and tissue lipid levels and increase insulin sensitivity more than a diet containing red meat (RM). Rats were fed a high-fat diet (300 g fat/kg diet) for 9 wk, then switched to a diet containing either 80 or 320 g protein/kg diet, provided by either WPC or RM, for 6 wk (n = 8). The rats were then killed after overnight food deprivation. High dietary protein reduced energy intake (P < 0.001) and visceral (P < 0.001), subcutaneous (P < 0.001), and carcass fat (P < 0.05). Increasing the dietary density of WPC, but not of RM, reduced body weight gain by 4% (P < 0.001). Dietary WPC also reduced plasma insulin concentration by 40% (P < 0.05) and increased insulin sensitivity, compared to RM (P < 0.05). These findings support the conclusions that a high-protein diet reduces energy intake and adiposity and that whey protein is more effective than red meat in reducing body weight gain and increasing insulin sensitivity.
Belobrajdic
Damien P
DP
Discipline of Physiology, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA, 5000, Australia. Commonwealth Scientific and Industrial Research Organization Health Sciences and Nutrition, Adelaide, SA, 5000, Australia.
McIntosh
Graeme H
GH
Owens
Julie A
JA
D000818:Animals; D001823:Body Composition; D004032:Diet; D002149:Energy Intake; D006728:Hormones / Q000097:blood; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D050356:Lipid Metabolism; D008297:Male; D008460:Meat; D008894:Milk Proteins / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar; D015430:Weight Gain; D000067816:Whey Proteins
D006728:Hormones; D007328:Insulin; D008894:Milk Proteins; D000067816:Whey Proteins