Effects of two dietary fibers as part of ready-to-eat cereal (RTEC) breakfasts on perceived appetite and gut hormones in overweight women

Abstract

The effects of an enzyme-hydrolyzed arabinoxylan from wheat (AXOS) versus an intact arabinoxylan from flax (FLAX) added to a ready-to-eat cereal (RTEC) on the postprandial appetitive, hormonal, and metabolic responses in overweight women (BMI 25.0-29.9 kg/m2) were evaluated. Subsequent meal energy intake was also assessed. Two randomized, double-blind, crossover design studies were completed. For trial 1, the participants consumed the following RTEC breakfast, matched for total weight and varied in energy content: low-fiber (LF, 4 g); high-fiber (HF, 15 g) as either AXOS or FLAX. For trial 2, the participants consumed LF, HF-AXOS, and HF-FLAX RTECs but also consumed another LF breakfast that was isocaloric (LF-iso) to that of the HF breakfasts. Perceived appetite and blood samples (trial 2 only) were assessed before and after breakfast. An ad libitum lunch was offered 4 h post-breakfast. No differences in postprandial appetite responses were observed among any breakfasts in either trial. The HF-AXOS and HF-FLAX led to increased postprandial GLP-1 and peptide YY (PYY) concentrations vs. LF-iso. No differences were observed in lunch meal energy intake among breakfast meals in either trial. Collectively, these data suggest that 15 g of low molecular weight fiber added to RTECs did not affect perceived appetite or subsequent energy intake despite differences in satiety hormone signaling in overweight females.

Figure 1

Hunger Score change from baseline following consumption of each breakfast. (a) Clinical Trial 1. Data are presented as mean ± SEM, based on 30 subjects. (b) Clinical Trial 2. Data are presented as mean ± SEM, based on 36 subjects. There were no significant differences between treatments at any time point (p > 0.05) in either trial. LF: low-fiber RTEC; HF-AXOS: high-fiber (HF) RTEC with AXOS fiber; HF-FLAX: high-fiber (HF) RTEC with FLAX fiber; LF-iso: isocaloric RTEC to that of the HF breakfasts.

Figure 2

Plasma hormone concentrations at selected time points: (a) active ghrelin, (b) active GLP-1, (c) total PYY. Significant differences among groups are signified as follows: *** p < 0.001; ** p < 0.01; * p < 0.05. LF: low-fiber RTEC; HF-AXOS: high-fiber (HF) RTEC with AXOS fiber; HF-FLAX: high-fiber (HF) RTEC with FLAX fiber; LF-iso: isocaloric RTEC to that of the HF breakfasts.

Figure 3

Plasma glucose and insulin concentrations at selected time points: (a) glucose, (b) insulin. Significant differences among groups are signified as follows: *** p < 0.001; ** p < 0.01; * p < 0.05. LF: low-fiber RTEC; HF-AXOS: high-fiber (HF) RTEC with AXOS; HF-FLAX: high-fiber (HF) RTEC with FLAX fiber; LF-iso: isocaloric RTEC to that of the HF breakfasts.