It is the largest study yet designed to evaluate the effects of particular types of grains on body weight and body fat, as well as the first study to focus specifically on rye. The study included 242 overweight men and women between the ages of 30 and 70 who were randomly assigned carefully adjusted daily amounts of refined wheat or whole-grain rye products with the same energy value. All participants also received the same general advice on healthy eating from a dietitian. The participants were examined at the start of the study, halfway through, and at twelve weeks, when the study ended.
"The results were clear - the participants who received rye products lost more weight overall, and their levels of body fat decreased compared to those who received wheat products," said Kia Nohr Iversen, a researcher at the Division of Food and Nutrition Science at the Chalmers University of Technology, and lead author of the study, which forms part of her recently presented doctoral dissertation. Although both the rye and wheat groups lost weight during the study, those who ate rye products lost an average of one kilogram more than those who ate wheat products, with the difference attributable to fat loss.
Different people can react to the same foods in different ways, depending on, for example, the particular bacteria present in the gut, and the way they break down. At the Division of Food and Nutrition Science at the Chalmers University of Technology, research is underway into how diet can be better adapted to the individual level, providing precision nutritional advice to yield greater health benefits. The new study offered unique data that can be used to further research in this area.