A Soybean Peptide Isolate Diet Promotes Postprandial Carbohydrate Oxidation and Energy Expenditure in Type II Diabetic Mice

Abstract

The aim of the present study was to determine the effects of dietary proteins on the oxidation of dietary carbohydrate and lipids in type II diabetic mice. KK-A(y) strain mice were provided free access to a high fat diet (30% of energy as fat) for an initial 4-wk period to induce diabetes. To reduce body weight gain, the mice were subsequently fed restrictive isoenergetic and isonitrogenous diets (35% of energy as protein and 5% as fat) based on either casein or soy protein isolate hydrolysate (SPI-H) for 4 wk. To measure exogenous carbohydrate and lipid oxidation, the mice were fed a diet containing (13)C-glucose or (13)C-triolein while they were in a respiratory chamber for 72 h. Postprandial energy expenditure was higher in the SPI-H than in the casein group; this difference was due to an increase in postprandial exogenous and endogenous carbohydrate oxidation. There were no differences in 24-h energy expenditure between dietary groups. Oxidation of exogenous carbohydrate tended to be higher (P = 0.054) in the SPI-H group during the 24 h of measurement. Fecal excretion of (13)C-glucose was lower but the excretion of lipid was higher in mice fed the SPI-H diet than in casein-fed mice. These results indicate that in type II diabetic mice, dietary SPI-H not only inhibits the absorption of dietary lipids and increases the absorption of dietary carbohydrates but also augments postprandial energy expenditure, which is accompanied by a postprandial increase in oxidation of dietary carbohydrates.

Soy Protein Suppresses Gene Expression of Acetyl-CoA Carboxylase Alpha from Promoter PI in Rat Liver

“…5,9) The result that the fecal TG content in the rats in the SPI group was almost the same as that in the rats in the CAS group (Table 2) suggests that TG absorption from rat digestive organs was unaffected by dietary proteins. Previous studies have demonstrated that dietary soy peptides increase the excretion of fecal TG in genetically obese type II diabetic mice, 21,22) which does not coincide with the results of the present study. The increased fecal total lipid concentration of SPI-fed rats in the present study might be due to increased fecal steroid excretion, as shown in previous reports, 23,24) which might contribute to a decrease in hepatic TC levels.…”

Lupin <i>(Lupinus albus)</i> Protein Isolate (L-ISO) Has Adequate Nutritional Value and Reduces Large Intestinal Weight in Rats after Restricted and ad libitum Feeding

“…The reduction in body fat content seen in the 10-day study concurs with reduced body fat after legume protein consumption reported by other investigators in both laboratory animal [28,29] and human [30] studies -the proposed mechanisms have included activity of vegetable protein peptides on carbohydrate oxidation and energy expenditure [31] or a direct activity of these peptides on body fat metabolism such as through reduced lipogenic enzyme expression [28] . The contradictory effects on body fat seen in the two present rat studies are difficult to compare due to the differences in feeding time and restriction.…”

Aqueous Extract of Kotahla Himbutu (Salacia reticulata) Stems Promotes Oxygen Comsumption and Supresses Body Fat Accumulation in Mice

“…28,29) Some experiments have focused on the regulation of the gene expression of uncoupling proteins (UCPs) by dietary proteins, which could be important for studying energy expenditure. 30) Dietary supplementation of epigallocatechin gallate-a green tea bioactive polyphenol-reduces body fat accumulation and upregulates liver UCP2 mRNA in mice with diet-induced obesity.…”