A High-Protein Diet Reduces Weight Gain, Decreases Food Intake, Decreases Liver Fat Deposition, and Improves Markers of Muscle Metabolism in Obese Zucker Rats

Abstract

A primary factor in controlling and preventing obesity is through dietary manipulation. Diets higher in protein have been shown to improve body composition and metabolic health during weight loss. The objective of this study was to examine the effects of a high-protein diet versus a moderate-protein diet on muscle, liver and fat metabolism and glucose regulation using the obese Zucker rat. Twelve-week old, male, Zucker (fa/fa) and lean control (Fa/fa) rats were randomly assigned to either a high-protein (40% energy) or moderate-protein (20% energy) diet for 12 weeks, with a total of four groups: lean 20% protein (L20; n = 8), lean 40% protein (L40; n = 10), obese 20% protein (O20; n = 8), and obese 40% protein (O40; n = 10). At the end of 12 weeks, animals were fasted and euthanized. There was no difference in food intake between L20 and L40. O40 rats gained less weight and had lower food intake (p < 0.05) compared to O20. O40 rats had lower liver weight (p < 0.05) compared to O20. However, O40 rats had higher orexin (p < 0.05) levels compared to L20, L40 and O20. Rats in the L40 and O40 groups had less liver and muscle lipid deposition compared to L20 and L40 diet rats, respectively. O40 had decreased skeletal muscle mechanistic target of rapamycin complex 1 (mTORC1) phosphorylation and peroxisome proliferator-activated receptor gamma (PPARγ) mRNA expression compared to O20 (p < 0.05), with no difference in 5′ AMP-activated protein kinase (AMPK), eukaryotic translation initiation factor 4E binding protein 1 (4EBP1), protein kinase B (Akt) or p70 ribosomal S6 kinase (p70S6K) phosphorylation. The data suggest that high-protein diets have the potential to reduce weight gain and alter metabolism, possibly through regulation of an mTORC1-dependent pathway in skeletal muscle.

High Protein Diet that Cause Weight Loss and Lower Blood Glucose Level Have a Serious Impact on the Kidney Functions of Male Diabetic Obese Albino Rats

“…Rats fed an HP diet seemed to develop less leptin resistance than rats fed an NP diet, which is in line with their marked reduction of adipose tissue [31] [32]. Our finding was in agreement with previous studies of Farnsworth et al [5], Layman et al [33], Lynch and Adams [34], Pesta and Samuel, [10], and French et al [5].…”

“…However, some recent studies have shown a positive correlation between high protein intake and ESRD [51] [52]. A protective role for low protein diet has been suggested in patients with diabetic kidney disease; but no nutritional recommendations are made for individuals who are obese, or pre-diabetic [5].…”

“…Additionally, a high-protein diet has been shown to conserve fat-free mass and to contribute to fat mass loss [5]. The health benefits of high protein diets are well-established [4] [6] [7] [8] [9] [10] but the mechanisms of action that are responsible for these changes in body are still unclear [11].…”

“…There is a scientific controversy on the effects of long-term consumption of these diets, and it has recently been reported that high protein intake is related with a higher risk of weight gain and with increased risk of fatal and non-fatal outcomes [12]. Although there are many human and animal studies focused on the physiological, biochemical and/or pathological effects induced by specific nutrients and dietary factors, there have been relatively few studies investigating safety and potential adverse effects of HP diets but diets with high protein content are generally considered safe and healthy in subjects without any pathology [5].…”

Efek Protein Sempurna Dan Tidak Sempurna Terhadap Berat Badan Dan Albumin Tikus

“…Dengan demikian, konsumsi protein secara berlebihan dapat menyebabkan kegemukan 4 . Pada penelitian yang dilakukan oleh 5 pemberian diet tinggi protein (40% protein) dan diet protein sedang (20%) menurunkan berat badan, memperbaiki komposisi tubuh, dan mengatur respons glikemik. Diet tinggi protein selama 12 minggu yang dilakukan pada pada tikus gemuk mengurangi kenaikan berat badan secara signifikan.…”