High fiber rye foods and weight loss in overweight adults
What it found
In adults with overweight or obesity, eating high fiber rye products while on a calorie-restricted diet led to about 1 kg more weight loss and 0.5% more body fat loss than eating refined wheat.
The rye group also had lower levels of a marker of inflammation.
What they found
Studies in people
Weight loss
After 12 weeks, the rye group lost 1.08 kg more body weight than the wheat group. The rye group lost 2.9 kg on average, while the wheat group lost 1.8 kg.
Body fat loss
The rye group lost 0.54% more body fat than the wheat group. The difference was borderline significant after adjusting for multiple endpoints.
Inflammation marker
C-reactive protein was 28% lower in the rye group compared to the wheat group after 12 weeks. This difference remained after removing values that might indicate acute inflammation.
Appetite
There were no consistent differences between the groups in subjective appetite. The extra weight loss in the rye group could not be explained by differences in appetite.
Other health markers
No consistent differences were seen in blood pressure, blood sugar, insulin, or cholesterol between the groups. LDL cholesterol was higher in the wheat group at week 6 but not at week 12.
Gut symptoms
The rye group reported more bloating and less constipation than the wheat group. Both groups had low symptom scores overall.
What the authors conclude
“Consumption of high fiber rye products as part of a hypocaloric diet for 12 weeks caused a greater weight loss and body fat loss, as well as reduction in C-reactive protein, compared to refined wheat.”
Also in their conclusions
- They conclude that consuming high fiber rye products as part of a calorie-restricted diet for 12 weeks caused greater weight loss and body fat loss, as well as a reduction in C-reactive protein, compared to refined wheat.
- They state that the difference in weight loss could not be linked to differences in appetite response.
How it was done
Whole grain intake is linked to lower body weight in observational studies, but intervention studies have given mixed results. Rye is the richest whole grain in fiber and has been shown to increase fullness, so the authors wanted to test its effect on weight and body fat loss.
They randomly assigned 242 men and women aged 30 to 70 with overweight or obesity (BMI 27 to 35) to eat either high fiber rye products or refined wheat products for 12 weeks, while following a diet with a 500 kcal daily energy deficit. Body weight, body fat, blood markers, and appetite were measured at the start, week 6, and week 12.
What it can’t tell you
- This was a 12-week study, so it cannot show what happens over a longer period.
- The participants were adults with overweight or obesity, so the results may not apply to other groups.
Who paid
- Conflicts
- Declaration of competing interest RL is the founder of the Nordic Rye Forum, which is a research and dissemination platform for research related to rye and health that includes academic institutions as well as institutes and food industry with interest in rye across the Nordic region. The forum and its activities are funded by the industrial partners. RL is the PI of several projects funded by several cereal industrial companies. Such funding is used to carry out scientific studies. RL receives no salary, honorary, or by any other means has any personal economic benefits from industrial collaborations. Remaining authors declare no conflicts of interest.
- Authors work at
- Chalmers University of Technology, Sweden; Uppsala University, Sweden; Swedish University of Agricultural Sciences, Sweden
The paper
- Title
- A hypocaloric diet rich in high fiber rye foods causes greater reduction in body weight and body fat than a diet rich in refined wheat: A parallel randomized controlled trial in adults with overweight and obesity (the RyeWeight study)
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Iversen KN, Carlsson F, Andersson A, et al (2021). A hypocaloric diet rich in high fiber rye foods causes greater reduction in body weight and body fat than a diet rich in refined wheat: A parallel randomized controlled trial in adults with overweight and obesity (the RyeWeight study). Clinical nutrition ESPEN. doi:10.1016/j.clnesp.2021.07.007Free full textPubMed 34620312DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error