“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 researcher Kia Nøhr Iversen. “As we continue to look for the exact reasons why, our advice is to choose the rye bread instead of the sifted wheat bread.”
Making healthier choices
The researchers had over 240 overweight men and women, ranging in age from 30 to 70, involved in the study. For 12 weeks, the participants were eating the same quantities of either whole grain rye or refined wheat products. They also received dietary advice from a nutritionist and underwent evaluations twice over the course of the study.
Ultimately, all of the participants lost weight by the end of the study. However, those who ate rye products lost more weight and more body fat than those who ate the wheat products; weight loss was more than one kilogram higher for the group who ate rye products.
The researchers believe rye was better for weight loss because products with this type of grain tend to help keep consumers more full. That’s because there are higher levels of fiber in whole grain rye products that help moderate appetite.
Every person’s body is different
While rye grain was linked to greater weight loss overall, the researchers found that there was a big disparity among the participants in each group when it came to how their bodies reacted to either rye or wheat. They say this could be because of the differences in gut bacteria among all of the participants, but the team plans to do more work to better understand why these disparities exist.
“Although we saw an overall difference in weight loss between the rye and the wheat group, there was also very large variation within those groups,” said researcher Rikard Landberg. “Increasing our understanding of why different people respond differently to the same foods can pave the way for more specifically tailored diets based on individual needs. We are currently investigating whether certain specific bacteria in the intestine might be the explanation behind why some people lost more weight than others who were also on the rye diet.”