The impact of the consumption of different bread types on body weight and cardiometabolic health - a systematic review of randomised clinical trials

This project aims to perform a systematic literature review (SLR) of randomised controlled trials (RCTs) examining the impact of different bread types consumption on key clinical outcomes, such as body mass index (BMI) and weight changes among healthy individuals. This systematic literature review was conducted in adherence to the methodological standards set forth by the National Institute for Health and Care Excellence (NICE), ensuring rigorous and transparent reporting. The search strategies were developed and implemented on October 31st, 2024 and updated on March 11th, 2026, in selected bibliographical databases, clinical trials registers, and grey literature across nutrition- and metabolism-specific conference websites from the last 5 years (2021-2026). The screening and data extraction processes were conducted independently by two reviewers, with discrepancies resolved through consensus or consultation with senior analysts. Quality assessment was performed using the Risk of Bias 2.0 tool, focusing on key outcomes such as BMI/weight change and total cholesterol/low-density lipoprotein (LDL) change. In October 2024, a total of 3,142 records were identified, and after removing duplicates and excluding out-of-scope studies, 12 unique trials (14 publications) were included in the review. The update of the literature search in March 2026 allowed the addition of a trial conducted in 2025. In total, our systematic review examines 13 unique trials. The 13 included trials evaluated clinical outcomes following bread consumption (test bread vs. control bread) over a 3-month period (8-16 weeks). Six were conducted in healthy individuals, while the remaining seven enrolled participants with metabolic risk factors such as overweight or elevated cholesterol. The trials varied widely in bread interventions, including but not limited to whole-grain/high-fibre wheat or rye breads; refined wheat breads; potato-wheat bread; long and short fermentation whole-grain wheat sourdough bread; and oat β-glucan breads. Data availability and presentation varied across outcomes, with BMI, weight, fat mass, and lipid profiles being the most reported.