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<p><a href="https://peterattiamd.com/ama77/?utm_source=podcast-feed&utm_medium=referral&utm_campaign=251110-pod-ama76&utm_content=251110-pod-ama77-podfeed"> View the Show Notes Page for This Episode</a></p> <p><a href="https://peterattiamd.com/subscribe/?utm_source=podcast-feed&utm_medium=referral&utm_campaign=251110-pod-ama77&utm_content=251110-pod-ama77-podfeed"> Become a Member to Receive Exclusive Content</a></p> <p><a href="https://peterattiamd.com/newsletter/?utm_source=podcast-feed&utm_medium=referral&utm_campaign=251110-pod-ama77&utm_content=251110-pod-ama77-podfeed"> Sign Up to Receive Peter's Weekly Newsletter</a></p> <p>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.</p> <p>If you're not a subscriber and are listening on a podcast player, you'll only be able to hear a preview of the AMA. If you're a subscriber, you can now listen to this full episode on your <a href="https://peterattiamd.com/members/private-podcast-feed/?utm_source=podcast-feed&utm_medium=referral&utm_campaign=251110-pod-ama76&utm_content=251110-pod-ama77-podfeed">private RSS feed </a>or our website at the <a href="http://peterattiamd.com/ama77/?utm_source=podcast-feed&utm_medium=referral&utm_campaign=251110-pod-ama77&utm_content=251110-pod-ama77-podfeed">AMA #77 show notes page</a>. If you are not a subscriber, you can learn more about the subscriber benefits <a href="https://peterattiamd.com/subscribe/?utm_source=podcast-feed&utm_medium=referral&utm_campaign=251110-pod-ama77&utm_content=251119-pod-ama77-podfeed">here</a>.</p> <p><strong>We discuss:</strong></p> <ul type="disc"> <li>Why it's time to re-examine the evidence behind dietary fiber recommendations [2:00];</li> <li>Why it's hard to isolate fiber's true effects on health: the limits of nutritional epidemiology [5:45];</li> <li>Defining dietary fiber: what it is, how it's digested, and why different types have different effects [8:15];</li> <li>Understanding fiber properties: how solubility, viscosity, and fermentability shape its effects in the body [11:15];</li> <li>Resistant starches explained: types, food sources, and how cooking and cooling influence their benefits [16:30];</li> <li>A framework for evaluating each of the major health claims linked to fiber [19:15];</li> <li>How fiber can support weight loss: mechanisms, realistic expectations, and its complementary role to broader dietary strategies [20:30];</li> <li>How fiber modestly improves glycemic control by reducing glucose spikes and insulin demand [26:15];</li> <li>How fiber modestly lowers LDL cholesterol and supports cardiovascular health [34:30];</li> <li>How fiber compares to other available tools and strategies for managing lipids, blood sugar, and weight [42:00];</li> <li>Fiber's role in colon cancer prevention: mechanisms, evidence, and limitations [45:30];</li> <li>Is fiber necessary for colon cancer prevention in otherwise healthy individuals? [53:30];</li> <li>Why some people have adverse reactions to certain types of fiber, and how to manage them [56:00];</li> <li>A general strategy for dietary fiber: combine multiple fiber types through whole foods and supplements [58:45];</li> <li>Why total fiber intake is more important than the ratio of soluble-to-insoluble fiber [1:02:45];</li> <li>The optimal timing and context for consuming fiber to maximize blood sugar control and metabolic benefits [1:05:00];</li> <li>How food processing affects the functional properties of fiber, the differences between supplement forms and natural sources, and why whole foods generally remain the best option [1:06:45];</li> <li>Fiber's potential to interfere with medication absorption [1:09:30];</li> <li>How to safely increase fiber intake: ramp up gradually and stay hydrated [1:12:00];</li> <li>Final takeaway on fiber: modest benefits, strong rationale, low downside [1:13:00];</li> <li>Peter's carve-out: lessons and inspiration from the Acquired podcast [1:14:30]; and</li> <li>More.</li> </ul> <p>Connect With Peter on <a href="https://twitter.com/PeterAttiaMD">Twitter</a>, <a href="https://www.instagram.com/peterattiamd/">Instagram</a>, <a href="https://www.facebook.com/peterattiamd/">Facebook</a> and <a href="https://www.youtube.com/channel/UC8kGsMa0LygSX9nkBcBH1Sg">YouTube</a></p>
Actionable Insights
Take a closer look at the data regarding topics like fiber to make well-informed decisions, especially if you choose not to be completely dogmatic or extreme in your approach.
2. Strategic Fiber Approach
Move beyond the simplistic goal of just getting enough fiber towards a more strategic approach that maximizes its actual benefits by understanding what it does, where it’s beneficial, and how to use it effectively.
3. Seek Professional Medical Advice
This podcast is for general informational purposes only; always seek the assistance of your healthcare professionals for any medical conditions and do not disregard or delay in obtaining professional medical advice.
4. Prioritize Whole Food Fiber
Aim to get fiber from whole food sources, as this typically provides a beneficial mix of different fiber types with varied properties.
5. Prepare Resistant Starches
Cook starchy foods like potatoes or rice, then cool them in the refrigerator overnight to increase RS3 resistant starch; you can warm them up, but avoid getting them too hot to preserve the resistant starch.
6. Consume Oats for Fiber
Eat oats to benefit from beta-glucan, a soluble gel-forming and fermentable fiber, along with insoluble fiber, which provides gel formation, prebiotic effects, and favorable blood glucose impact.
7. Eat Beans for Diverse Fiber
Incorporate beans into your diet as they are high in fiber and provide a diverse mix of fiber types, including resistant starches, insoluble fiber, and soluble fibers with varying fermentability.
8. Avoid Processed Oats
Avoid highly processed oats, such as instant oatmeal, as processing can diminish the capacity to obtain RS1 resistant starch.
9. Use Fiber Properties Table
Refer to the table in the show notes, which lists common fibers, their properties, and food sources, to help you strategically increase your intake of specific fiber types you prioritize.
10. Tailor Fiber Intake
If you might not tolerate certain fibers well, tailor your intake accordingly based on how different types of fiber work in the body.
11. Consider RS2 Supplements
If you specifically want to increase your intake of RS2 resistant starch, consider buying an RS2 supplement, as this type is most likely to be found in supplement form.
12. Access Full AMA Episodes
To access full AMA episodes and other membership benefits, visit peteratiyahmd.com/subscribe.
13. Check Disclosures
To understand potential conflicts of interest, visit peteratiamd.com/about for an up-to-date and active list of all disclosures.