The effects of bulking, viscous and gel-forming dietary fibres on satiation

Abstract

The objective was to determine the effects of dietary fibre with bulking, viscous and gel-forming properties on satiation, and to identify the underlying mechanisms. We conducted a randomised crossover study with 121 men and women. Subjects were healthy, non-restrained eaters, aged 18–50 years and with normal BMI (18·5–25 kg/m2). Test products were cookies containing either: no added fibre (control), cellulose (bulking, 5 g/100 g), guar gum (viscous, 1·25 g/100 g and 2·5 g/100 g) or alginate (gel forming, 2·5 g/100 g and 5 g/100 g). Physico-chemical properties of the test products were confirmed in simulated upper gastrointestinal conditions. In a cinema setting, ad libitum intake of the test products was measured concurrently with oral exposure time per cookie by video recording. In a separate study with ten subjects, 4 h gastric emptying rate of a fixed amount of test products was assessed by 13C breath tests. Ad libitum energy intake was 22 % lower for the product with 5 g/100 g alginate (3·1 (sd 1·6) MJ) compared to control (4·0 (sd 2·2) MJ, P< 0·001). Intake of the other four products did not differ from control. Oral exposure time for the product with 5 g/100 g alginate (2·3 (sd 1·9) min) was 48 % longer than for control (1·6 (sd 0·9) min, P= 0·01). Gastric emptying of the 5 g/100 g alginate product was faster compared to control (P< 0·05). We concluded that the addition of 5 g/100 g alginate (i.e. gel-forming fibre) to a low-fibre cookie results in earlier satiation. This effect might be due to an increased oral exposure time.