Study: Rye for breakfast increases satiety

Stockholm / SE. (nj) Dieters are often told to eat a filling breakfast in order to avoid overeating later in the day. The latest addition to that advice – eat rye bread. A study from the Swedish University of Agricultural Sciences (SLU) found eating rye increases the feeling of being full and leads to reduced food intake later in the day (for as long as eight hours) compared with eating wheat bread. The strongest effect was for rye bread made with rye bran.

For European bakers – especially Russian, Polish, Finnish and German bakers – this finding is no surprise. They have a very long tradition in baking rye bread – with rye sourdough, rye whole grain and rye meal in different granulations. Also «mixed bread» (with rye and wheat flour) brings a lot of health benefits. No doubt: Where rye- or rye-wheat-bread has a long tradition, nutrition is healthier.

Breakfast is a good place to start with rye products, the Swedish authors say. But they note: «In the Western world the majority of the whole grain products eaten are based on wheat, while the consumption of oats and especially rye and barley is much lower. That rye possibly has superior satiating properties may be due to its high dietary fiber content and possibly fiber composition», they Swedish researchers say. People eating rye bread also had a lower insulin response – and: the bread tastes really good.

Abstract

Several studies report that dietary fibre from different sources promotes the feeling of satiety and suppresses hunger. However, results for cereal fibre from rye are essentially lacking. The aim of the present study was to investigate subjective appetite during eight hours after intake of iso-caloric rye bread breakfasts varying in rye dietary fibre composition and content.

Methods: The study was divided into two parts. The first part (n=16) compared the satiating effect of iso-caloric bread breakfasts including different milling fractions of rye (bran, intermediate fraction (B4) and sifted flour). The second part (n=16) investigated the dose-response effect of rye bran and intermediate rye fraction, each providing five or eight grams of dietary fibre per iso-caloric bread breakfast. Both study parts used a wheat bread breakfast as reference and a randomised, within-subject comparison design. Appetite (hunger, satiety and desire to eat) was rated regularly from just before breakfast at 08:00 until 16:00. Amount, type and timing of food and drink intake were standardised during the study period.

Results: The Milling fractions study showed that 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. At a comparison between the rye bread breakfasts the one with rye bran induced the strongest effect on satiety. 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. In the Dose-response study both levels of rye bran and the lower level of intermediate rye fraction resulted in an increased satiety before lunch compared with the wheat reference bread breakfast. Neither the variation in composition between the milling fractions nor the different doses resulted in significant differences in any of the appetite ratings when compared with one another.

Conclusions: The results show that rye bread can be used to decrease hunger feelings both before and after lunch when included in a breakfast meal. Rye bran induces a stronger effect on satiety than the other two rye fractions used when served in iso-caloric portions. Trial registration number NCT00876785

Info: Effect of rye bread breakfasts on subjective hunger and satiety – a randomized controlled trial (PDF, 26 pages, 223 KB) – Authors: Hanna Isaksson, Helena Fredriksson, Roger Andersson, Johan Olsson and Per Aman (2009).