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In this "Ask Me Anything" (AMA) episode, Peter breaks down the science of dietary fiber, moving beyond the blanket advice to "eat more fiber" to uncover what it actually does in the body and where its benefits are truly supported by evidence. He explains how different types of fiber—soluble, insoluble, viscous, and fermentable—affect digestion, satiety, weight management, and glycemic control, and compares their impact to other, more potent metabolic tools. Peter also examines how certain fibers influence lipid metabolism and cardiovascular risk, evaluates the strength of evidence for fiber's role in colorectal cancer prevention, and highlights why some individuals may not tolerate specific fibers well. The discussion concludes with practical guidance on moving past generic fiber targets toward a more strategic and personalized approach that maximizes the true benefits of fiber.

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We discuss:

• Why it's time to re-examine the evidence behind dietary fiber recommendations [2:00];

• Why it's hard to isolate fiber's true effects on health: the limits of nutritional epidemiology [5:45];

• Defining dietary fiber: what it is, how it's digested, and why different types have different effects [8:15];

• Understanding fiber properties: how solubility, viscosity, and fermentability shape its effects in the body [11:15];

• Resistant starches explained: types, food sources, and how cooking and cooling influence their benefits [16:30];

• A fr