Wheat bran is rich in dietary fiber, particularly insoluble fiber, and its use in weight loss is supported by scientific evidence, primarily through its effects on satiety and digestive health. Insoluble fiber from wheat bran adds bulk to the diet without adding significant calories, which can help increase feelings of fullness and reduce overall calorie intake. Several clinical studies have indicated that higher intake of dietary fiber, including wheat bran, is associated with lower body weight and reduced risk of obesity. Meta-analyses and reviews suggest that fiber supplementation (including wheat bran) can modestly enhance weight loss efforts when combined with calorie control and lifestyle changes.

Mechanistically, wheat bran slows gastric emptying, promotes regular bowel movements, and may modulate gut hormones involved in appetite regulation. However, the effect size is generally moderate, and wheat bran alone is unlikely to cause significant weight loss without concurrent dietary and behavioral modifications. While wheat bran has been used historically as a digestive aid, its application for weight loss is primarily based on modern nutritional science rather than longstanding traditional use. In summary, wheat bran is scientifically justified as a supportive component in weight management strategies, but should not be relied upon as a sole intervention.