While the effects of eating a fibre-rich diet are well documented in the literature, reports on how cereal fibre from rye may increase feelings of fullness are lacking, according to researchers from Swedish University of Agricultural Sciences.
Writing in the Nutrition Journal, the Swedish researchers report that consuming a rye breakfast suppressed appetite over the following 3 hours more than a wheat breakfast.
In addition, the strongest effect on satiety was achieved by rye bread formulated with rye bran.
The scientists collaborated with Swedish bakery cooperative Lantmännen R&D, which also financed and produced the test products.
“The levels of rye used in the breads were based on realistic amounts to create palatable, voluminous bread,” explained the researchers, led by Hanna Isaksson.
“The bread portion, together with additional breakfast foods, comprised what would be considered a normal breakfast meal. The amount of calories corresponded to recommended breakfast intake.”
Satiety is seen as a key target in the battle against obesity, with figures from Europe showing that up to 27 per cent of men, 38 per cent of women, and 3 million children are clinically obese in some parts of the bloc.
The retail market for weight management products was estimated by Euromonitor International to be worth US$0.93bn (€0.73) in Europe in 2005 and $3.93bn in the US, indicating that call to slim down or face the health consequences is being heeded by a slice of the overweight population at least.
Foods marketed for satiety enhance feelings of fullness after eating, acting as a boost to a person's will-power and helping them avoid a reversion to old habits in a bid to stave off hunger pangs, or 'grazing' in between meals.
Study details
The researchers investigated the effects of rye bread formulated with different quantities of rye dietary fibre. All the bread contained the same caloric values.
Sixteen volunteers (average age 35, average BMI 22 kg/m2) and assigned them to eat breads made from rye bran, an intermediate fraction, or sifted rye flour, and compared this to sifted wheat flour.
“Each of the rye breakfasts resulted in a suppressed appetite during the time period before lunch (08:30-12:00) compared with the wheat reference bread breakfast,” wrote the researchers.
“In the afternoon the effect from all three rye bread breakfasts could still be seen as a decreased hunger and desire to eat compared to the wheat reference bread breakfast,” they added.
A second experiment looking at the effects of different rye bran doses, providing 5 and 8 grams per breakfast, found that both levels of rye bran produced an “increased satiety before lunch, compared with the wheat reference bread breakfast”.
“The results show that rye bread can be used to decrease hunger feelings both before and after lunch when included in a breakfast meal,” said the researchers. “Rye bran induces a stronger effect on satiety than the other two rye fractions used when served in iso-caloric portions,” they concluded.
Scientists from contract research organisation KPL Good-Food-Practice AB also participated in the research.
Source: Nutrition Journal
2009, 8:39, doi:10.1186/1475-2891-8-39
“Effect of rye bread breakfasts on subjective hunger and satiety: a randomized controlled trial"
Authors: Hanna Isaksson, H. Fredriksson, R. Andersson, J. Olsson, P. Aman