Yeast hydrolysate can reduce body weight and abdominal fat accumulation in obese adults

OBJECTIVE

The aim of this study was to examine the effect of yeast hydrolysate on the abdominal fat in obese humans.

METHODS

We observed the effects of yeast hydrolysate that had a molecular weight below 10 kDa on the anti-abdominal fat accumulation in obese men and women ages 20 to 50 y for 10 wk. The abdominal fat mass was assessed by computed tomographic scans.

RESULTS

By the sixth week, the reductions in energy intake in the yeast group (yeast hydrolysate 1 g/d) were significantly greater than those in the control group (placebo 1 g/d) (P < 0.05). The body weight and body mass index (BMI) were significantly reduced by week 10 compared with baseline in the yeast group, and these differences were significantly greater than those in the control group: body weight 0.83 kg versus -2.60 k g (P < 0.001), BMI 0.29 kg/m(2) versus -0.90 kg/m(2) (P < 0.001). Despite the increased loss of body weight in the yeast group, lean body mass did not significantly differ between the two groups. Body fat mass in the control group did not significantly change between baseline and week 10. However, the yeast group lost a significant amount of body fat mass after 10 wk of treatment (P < 0.01). The differences in abdominal fat thickness and abdominal circumference between the two groups were significant after 10 wk of treatment (P < 0.001). The total abdominal fat area in the yeast group was significantly lower than in the control group after 10 wk of treatment (-7.06 cm(2) versus -17.34 cm(2); P < 0.01).

CONCLUSIONS

Yeast hydrolysate can reduce body weight and the accumulation of abdominal fat without an adverse effect on lean body mass in obese adults, regardless of sex, via the reduction of energy intake.

Effects of yeast hydrolysate on hepatic lipid metabolism in high-fat-diet-induced obese mice: yeast hydrolysate suppresses body fat accumulation by attenuating fatty acid synthesis

AIMS

We observed whether the anti-obesity activity of yeast hydrolysate (YH) was due to the alteration of lipid-regulating enzyme activities.

METHODS

Male ICR mice were divided into four groups: a normal diet group (ND; 4.2% fat), a high-fat diet group (HF; 27.7% fat), an HF group treated orally with 0.5% or 1% YH in the drinking water (HF+YH0.5; 27.7% fat and HF+YH1; 27.7% fat).

RESULTS

After 5 weeks, the YH groups (HF+YH0.5=3.92±0.17 g/100 g BW and HF+YH1=3.76±0.13 g/100 g BW) had significantly lower levels of epididymal fats compared to the HF group (4.91±0.29 g/100 g BW; p<0.05). YH supplementation produced a decrease in serum triglycerides and low-density lipoprotein cholesterol concentrations and body weight gain, and produced a dose-dependent significant increase in serum ghrelin compared with the HF group (p<0.05). Hepatic glucose-6-phosphate dehydrogenase (G6PD) activity was inhibited by YH supplementation compared with the HF group, and mice treated orally with 1% YH exhibited a significant decrease in hepatic malic enzyme (ME) activity compared to obese mice treated with the vehicle (HF=10.44±2.74 nmol/min/mg protein vs. HF+YH1=6.68±2.23 nmol/min/mg protein; p<0.05).

CONCLUSIONS

YH supplementation suppressed body fat accumulation by attenuating fatty acid synthesis through the downregulation of hepatic G6PD and ME activities.