#306 - Does Intermittent Fasting Actually Work? | Dr. Courtney Peterson & Mike Haney

<p>Is intermittent fasting biohacker wellness hype or legit health intervention? Some studies show real benefits, others find nothing, and the occasional headline calls it bad for your heart.</p><p><br></p><p>Dr. Courtney Peterson has spent nearly two decades running some of the field&#39;s most tightly controlled feeding trials, and her data points to a clear pattern: there is a real effect to a restricted eating window, but <em>when</em> you eat may matter as much as <em>how long</em> you fast. Her studies found that eating in a short window early in the day lowers blood pressure and improves insulin sensitivity, even without weight loss. A physicist by training, she brings that same rigor to a field built mostly on people&#39;s own food diaries.</p><p><br></p><p><strong>Free course: Improve your metabolic health</strong></p><p>Get our free email course on how glucose, nutrition, exercise, sleep, and measurement can help you build habits that support better energy and long-term health: ⁠⁠⁠⁠⁠⁠⁠⁠⁠<a href="https://www.levels.com/partner/multimedia?utm_source=podcast&utm_medium=link&utm_content=wnl&partner=Peterson" target="_blank" rel="ugc noopener noreferrer">https://levels.link/wnl⁠</a></p><p><br></p><p><strong>🎙️ About the Guest:</strong></p><p>Dr. Courtney Peterson is an Associate Professor of Nutrition, Harvard T.H. Chan School of Public Health. She holds a PhD in physics from Harvard and leads clinical trials on intermittent fasting, meal timing, and circadian rhythms.</p><p><br></p><p><strong>📍What Dr. Courtney Peterson &amp; Mike Haney discussed:</strong></p><ul><li>0:00 Introduction</li><li>02:39 The three types of intermittent fasting</li><li>05:29 The 2012 mouse study that started the field</li><li>11:24 Why fasting works through appetite, not extra calories</li><li>13:48 Her six-hour study: lower blood pressure, no weight loss</li><li>25:34 Why results depend on who&#39;s being studied</li><li>28:45 The shift worker whose health got worse</li><li>36:45 Her theory: timing over fasting length</li><li>43:08 Heart attacks, blood pressure, and the body&#39;s clock</li><li>45:55 The camping trip that reset people&#39;s body clocks</li><li>58:11 Early findings from her unpublished aging study</li><li>1:08:16 Should you eat ice cream for breakfast?</li></ul><p><br></p><p><strong>🔗 Helpful Links:</strong></p><ul><li>Time-Restricted Feeding without Reducing Caloric Intake Prevents Metabolic Diseases in Mice Fed a High-Fat Diet (Hatori et al., 2012) — <a href="https://doi.org/10.1016/j.cmet.2012.04.019" target="_blank" rel="ugc noopener noreferrer">https://doi.org/10.1016/j.cmet.2012.04.019</a></li><li>Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes (Sutton et al., 2018) — <a href="https://doi.org/10.1016/j.cmet.2018.04.010" target="_blank" rel="ugc noopener noreferrer">https://doi.org/10.1016/j.cmet.2018.04.010</a></li><li>Early Time-Restricted Feeding Improves 24-Hour Glucose Levels and Affects Markers of the Circadian Clock, Aging, and Autophagy in Humans (Jamshed et al., 2019) — <a href="https://doi.org/10.3390/nu11061234" target="_blank" rel="ugc noopener noreferrer">https://doi.org/10.3390/nu11061234</a></li><li>Calorie Restriction with or without Time-Restricted Eating in Weight Loss (Liu et al., 2022) — <a href="https://doi.org/10.1056/NEJMoa2114833" target="_blank" rel="ugc noopener noreferrer">https://doi.org/10.1056/NEJMoa2114833</a></li></ul><p><br></p><p><strong>Watch the conversation:</strong> <a href="https://youtu.be/dKauIgX3IH4" target="_blank" rel="ugc noopener noreferrer">https://youtu.be/dKauIgX3IH4</a></p><p><strong>Find us on YouTube:</strong> <a href="https://youtube.com/levelshealth?sub_confirmation=1" target="_blank" rel="ugc noopener noreferrer">⁠⁠⁠⁠https://youtube.com/levelshealth?sub_confirmation=1⁠⁠⁠</a></p><p><br></p><p><strong>👋 Who we are:</strong></p><p>Levels helps you understand your metaboli