The Proof with Simon Hill

In this episode, I’m joined by Dr Kristen Knutson to unpack circadian health and how timing influences our metabolism, cardiovascular health, and sleep quality. We discuss the role of morning light, meal timing, exercise, and regularity, and why modern lifestyles often push our biology out of sync. Dr Knutson also clarifies common misconceptions about melatonin, wearable sleep trackers, and what to do if you wake up in the middle of the night and struggle to fall back asleep. What We Cover What circadian health is and how disruption occurs in everyday life Why morning light is the strongest signal for your internal clock Meal timing basics, including why avoiding food close to bedtime matters Exercise timing and the simple rule most people should follow Sleep health beyond hours slept: quality, timing, and regularity Practical strategies for waking during the night and falling back asleep Understanding circadian rhythms can help you make small changes that support better sleep, better energy, and long-term health. To connect with the guest, follow Dr Kristen Knutson on LinkedIn and explore her research profile via Northwestern Feinberg. Intro (00:00) America’s 24/7 Problem (02:48) Night Owls: Is Your Sleep Schedule Genetic? (14:04) Why "Catching Up" on Sleep Fails (20:00) How to Use Light & Melatonin (29:16) Meal Timing and Weight Gain (37:27 The Best Fasting Window for Your Circadian Rhythm (43:25) Can Late Workouts Ruin Sleep? (48:07) Deep Sleep vs. REM (55:23) How Your Brain Fights to Recover (58:32) Hacks for Falling Back To Sleep Quickly (01:03:27) The Holy Trinity of Health: Diet, Exercise, and Sleep (01:12:00) One Simple Step to Start Today (01:15:56) This episode is brought to you by: 38TERA Consider 38TERA's DMN prebiotic supplement a daily multivitamin for your gut. Formulated by yours truly and gastroenterologist Dr Will Bulsiewicz. Use code THEPROOF for a discount at checkout. 38Tera ships to the United States, Australia, and New Zealand. Mill Mill is an odourless, fully automated food recycler that turns kitchen scraps into clean, dry grounds overnight with no smells or mess. Get $75 off and try it risk-free for 90 days at mill.com using code THEPROOF. Mill ships within the United States. Function Health Take charge of your health with advanced blood testing and personalised insights. Function Health offers a practical way to track key health markers such as cholesterol, blood sugar, and more. Learn more and join at functionhealth.com/simonhill for a $25 credit toward your membership. Only available to those living in the United States. Function Health ships to 48 U.S. states, excluding Rhode Island, Hawai‘i, and Puerto Rico. Shopify Shopify, the world's leading e-commerce platform, helps you turn browsers into buyers with the internet’s best-converting check out–up to 36% better compared to other leading e-commerce platforms. To boost your conversion rate, and grow your business, sign up for your one-dollar-per-month trial at shopify.com/proof. WHOOP Whoop, the most advanced fitness and health wearable available. Your personalised fitness and health coach to recover faster, sleep better, and train smarter. Claim your first month free on join.whoop.com/simon. Whoop ships to 56+ international markets, including the US, Canada, most of Europe, Australia, New Zealand, UAE, Singapore, and parts of Asia. Simon Hill, MSc, BSc (Hons) Creator of theproof.com Host of The Proof with Simon Hill Author of The Proof is in the Plants Subscribe & Connect: YouTube Apple Podcasts Spotify Instagram: @simonhill Twitter: @theproof Facebook: The Proof with Simon Hill

Dr Lauren Colenso-Semple and Dr Alyssa Olenick join me to answer a question I hear constantly from women in midlife: “Why am I putting in so much effort, but not seeing the results?” We break down what matters most for strength, body composition, and long term health, and what is simply noise. You’ll come away with a clear framework for resistance training, a realistic view of cardio, and a calmer approach to progress that does not rely on fear, perfection, or menopause specific gimmicks. What We Cover Why effort and the right stimulus matter more than “working hard” A simple full body lifting template for busy weeks How to know if you are training close enough to failure Why cardio is still important, and how to think about intensity The cortisol and overtraining myths that keep women stuck How protein, consistency, and dieting patterns affect results If you want a plan you can actually stick with, this one will help you focus on the basics that move the needle. Intro (00:00) The Real Reason Your Fitness Progress Has Stalled (02:00) Why Women Should Lift Heavy (10:40) Maximize Your Training ROI ( 21:29) Fitness Fact vs. Fiction (34:17) How Your Body Changes with Age (40:59) The Busy Woman’s Guide (53:30) Why Reps & Rest Matter ( 1:11:54) Which Goal Should You Prioritize in Midlife? ( 1:29:52) Eating for Muscle Growth (1:44:43) Building Muscle While Losing Fat (1:54:36) Finding Workouts You Love (2:09:13) HIIT, Zone 2, and What Your Heart Really Needs (2:14:58) Balancing Cardio Intensities (2:25:14) Signs Your Cardiovascular Training is Actually Working (2:30:25) Midlife Fitness Truths (2:38:02) Final Takeaways: Strategies for Longevity (2:47:29) Connect with Dr Lauren Colenso-Semple on Instagram and at drlaurencs.com. Follow Dr Alyssa Olenick on Instagram, listen to The Messy Middle Podcast, subscribe on YouTube, and visit doclyssfitness.com for practical, science based guidance on training and midlife health. This episode is brought to you by: 38TERA Consider 38TERA's DMN prebiotic supplement a daily multivitamin for your gut. Formulated by yours truly and gastroenterologist Dr Will Bulsiewicz. Use code THEPROOF for a discount at checkout. 38Tera ships to the United States, Australia, and New Zealand. Eight Sleep Upgrade your sleep with the Pod 5 Ultra by Eight Sleep. Clinically validated to deliver up to 1 extra hour of quality sleep per night through temperature control and biometric tracking. Use code THEPROOF for $350 off at eightsleep.com/theproof. Try it risk-free for 30 days, with worldwide shipping. Eight Sleep ships to the U.S. (excluding Alaska, Hawaii, and territories), Canada, Mexico, most of the EU, the U.K., Australia, the UAE, Saudi Arabia, and Switzerland. Pique Tea Pique’s Pu’er Tea Duo brings ancient fermentation into a simple daily ritual, delivering living nutrients that support digestion, metabolism, and sustained energy from the inside out. Unlock 20% off and establish your powerful foundation for sustained well-being at Piquelife.com/SIMON. Pique ships within the U.S. and to Australia, Canada, and select EU countries. Momentous My go-to supplement brand for protein and creatine is Momentous. Use code THEPROOF for up to 35% off your first order at livemomentous.com. Momentous ships to many countries worldwide depending on local import regulations. Simon Hill, MSc, BSc (Hons) Creator of theproof.com Host of The Proof with Simon Hill Author of The Proof is in the Plants Subscribe & Connect: YouTube Apple Podcasts Spotify Instagram: @simonhill Twitter: @theproof Facebook: The Proof with Simon Hill

Dr Brad Schoenfeld and Alan Aragon join me to explore protein requirements, recomposition, and how to structure resistance training for long-term strength and muscle retention. We discuss calorie deficits, effort, failure, recovery, and the training variables that matter most for healthy ageing. What We Cover Protein targets in and out of a calorie deficit Recomp versus surplus for muscle growth Effort, failure, and rep range myths Recovery, soreness, and cold exposure Cardio, interference, and real-world training balance If you care about building muscle, preserving strength, and avoiding unnecessary complexity, this episode is a practical guide to getting the basics right. To connect with the guests and explore more of their work, follow Alan Aragon on Instagram and Twitter, and visit his website at fitadvancement.com for research reviews, in-depth nutrition analysis, and mentorship offerings. You can follow Dr Brad Schoenfeld on Instagram and Twitter for ongoing insights into resistance training science and hypertrophy research. Want to support the show? The best way to support the show is to use the products and services offered by our sponsors. To check them out and enjoy great savings, visit theproof.com/friends. You can also support the show by leaving a review on the Apple Podcast app and sharing your favourite episodes with friends and family. This episode is brought to you by: 38TERA Consider 38TERA's DMN prebiotic supplement a daily multivitamin for your gut. Formulated by yours truly and gastroenterologist Dr Will Bulsiewicz. Use code THEPROOF for a discount at checkout. 38Tera ships to the United States, Australia, and New Zealand. Function Health Take charge of your health with advanced blood testing and personalised insights. Function Health offers a practical way to track key health markers such as cholesterol, blood sugar, and more. Learn more and join at functionhealth.com/simonhill for a $25 credit toward your membership. Only available to those living in the United States. Function Health ships to 48 U.S. states, excluding Rhode Island, Hawai‘i, and Puerto Rico. Momentous My go-to supplement brand for protein and creatine is Momentous. Use code THEPROOF for up to 35% off your first order at livemomentous.com. Momentous ships to many countries worldwide depending on local import regulations. IM8 With 92 nutrients, including Vitamin B12, Iodine, Selenium and Vitamin D, in highly absorbable forms, IM8 Daily Essentials is the perfect all-in-one daily multi-vitamin to ensure you meet your daily micronutrient needs. IM8 is offering an exclusive 10% off your first order with a free welcome kit when you enter the promo code SIMON at checkout on im8health.com. IM8 ships to 27 countries including the U.S., Canada, the U.K., Australia, and many regions across Europe, Asia, and South America. WHOOP Whoop, the most advanced fitness and health wearable available. Your personalised fitness and health coach to recover faster, sleep better, and train smarter. Claim your first month free on join.whoop.com/simon. Whoop ships to 56+ international markets, including the US, Canada, most of Europe (UK, Germany, France, etc.), Australia, New Zealand, UAE, Singapore, and parts of Asia. Simon Hill, MSc, BSc (Hons) Creator of theproof.com Host of The Proof with Simon Hill Author of The Proof is in the Plants Subscribe & Connect: YouTube Apple Podcasts Spotify Instagram: @simonhill Twitter: @theproof Facebook: The Proof with Simon Hill Nourish your gut with my Plant-Based Ferments Guide and download my Two-Week Meal Plan.

The 2025 US Dietary Guidelines are out, and they’ve sparked debate across the nutrition world. In this episode, I sit down with Dr David Katz to examine where the new recommendations align with science and where they diverge from the Dietary Guidelines Advisory Committee’s evidence review. We discuss the increased emphasis on meat and protein, contradictions around saturated fat and full-fat dairy, the controversy around seed oils, and what everyday people should actually focus on. What We Cover Why David believes science was subordinated to ideology The protein recommendation: do most Americans need more? Meat versus legumes for long-term health Saturated fat limits and whether the guidelines contradict themselves Full-fat dairy: beneficial, neutral, or harmful? Seed oils, essential fats, and common misconceptions The role of fibre and what gets displaced when protein increases The simple dietary pattern most associated with longevity Despite the noise, one principle remains consistent: eat real food, mostly plants, in balanced combinations. The fundamentals of good nutrition have not changed. You can connect with Dr David Katz on LinkedIn, Facebook, and X (Twitter). To learn more about his work, visit davidkatzmd.com, explore Diet ID, and discover the True Health Initiative. Intro (00:00) Initial Reactions to the New Dietary Guidelines (01:36) Political Influences on Dietary Guidelines (08:54) Specific Departures from Evidence-Based Recommendations (18:58) Historical Context and Modern Diet Quality (33:55) Protein Quality and Public Health (41:10) Regenerative Agriculture and Legumes (46:29) Understanding Fats in Our Diet (50:10) Contradictions in Dietary Guidelines (01:01:22) Dairy Consumption: Pros and Cons (01:10:20) Personalizing Your Diet for Optimal Health (01:19:25) This episode is brought to you by: 38TERA Consider 38TERA's DMN prebiotic supplement a daily multivitamin for your gut. Formulated by yours truly and gastroenterologist Dr Will Bulsiewicz. Use code THEPROOF for a discount at checkout. 38Tera ships to the United States, Australia, and New Zealand. ProLon Join my Guided Group Fasting Protocol starting March 9th using ProLon’s 5-Day Fasting Mimicking Diet, a science-backed program designed to support metabolic health while still allowing you to eat. Reserve your spot and claim 15% off at ProLonLife.com. ProLon ships within the United States. Mill Mill is an odourless, fully automated food recycler that turns kitchen scraps into clean, dry grounds overnight with no smells or mess. Get $75 off and try it risk-free for 90 days at mill.com/THEPROOF using code THEPROOF. Mill ships within the United States. Momentous My go-to supplement brand for protein and creatine is Momentous. Use code THEPROOF for up to 35% off your first order at http://livemomentous.com. Momentous ships to many countries worldwide depending on local import regulations. Eight Sleep Upgrade your sleep with the Pod 5 Ultra by Eight Sleep. Clinically validated to deliver up to 1 extra hour of quality sleep per night through temperature control and biometric tracking. Use code THEPROOF for $350 off at http://eightsleep.com/theproof. Try it risk-free for 30 days, with worldwide shipping. Eight Sleep ships to the U.S. (excluding Alaska, Hawaii, and territories), Canada, Mexico, most of the EU, the U.K., Australia, the UAE, Saudi Arabia, and Switzerland. Simon Hill, MSc, BSc (Hons) Creator of theproof.com Host of The Proof with Simon Hill Author of The Proof is in the Plants Subscribe & Connect: YouTube Apple Podcasts Spotify Instagram: @simonhill Twitter: @theproof Facebook: The Proof with Simon Hill

Can diet really reverse atherosclerosis, or is that an overpromise? Since sharing my own coronary CT angiogram results, this question has come up almost daily. In this episode, I revisit the best clinical trials to see what the evidence actually says. I break down six randomised controlled trials and explain how different dietary patterns influence plaque progression, plaque stability, and cardiovascular events. What we cover What atherosclerosis is and how it develops over time The tools used to measure plaque and artery health Evidence from six major randomised controlled trials on diet and atherosclerosis What Mediterranean and low fat diets actually achieve in practice Whether diet still matters if you are already on medication Key takeaways for prevention, progression, and long term heart health Diet cannot do everything, but the evidence shows it can meaningfully change the trajectory of atherosclerosis and reduce cardiovascular risk. Intro (00:00) What is Atherosclerosis? Understanding Plaque Buildup (02:06) 4 Ways to Measure Plaque: CAC, IMT, CTA, and QCA (05:35) The Gold Standard: 6 Randomized Controlled Trials (RCTs) (09:36) The 1990 Lifestyle Heart Trial (Dean Ornish) (12:20) The STARS Trial: Omega-3s & Fiber for Plaque Reversal (19:17) The SCRIP Trial: Stacking Lifestyle and Medication (23:36) PREDIMED Study: The Power of the Mediterranean Diet (26:53) CORDIOPREV Results: Secondary Prevention of Heart Disease (32:53) DISCO CT Trial: Modern AI Imaging of Plaque Changes (39:24) Summary of Clinical Evidence: What Actually Shrinks Plaque? (43:53) 3 Critical Takeaways for Managing Your Heart Health (46:25) This episode is brought to you by: 38TERA Consider 38TERA's DMN prebiotic supplement a daily multivitamin for your gut. Formulated by yours truly and gastroenterologist Dr Will Bulsiewicz. Use code THEPROOF for a discount at checkout. 38Tera ships to the United States, Australia, and New Zealand. Shopify Shopify, the world's leading e-commerce platform, helps you turn browsers into buyers with the internet’s best-converting check out–up to 36% better compared to other leading e-commerce platforms. To boost your conversion rate, and grow your business, sign up for your one-dollar-per-month trial at shopify.com/proof. IM8 With 92 nutrients, including Vitamin B12, Iodine, Selenium and Vitamin D, in highly absorbable forms, IM8 Daily Essentials is the perfect all-in-one daily multi-vitamin to ensure you meet your daily micronutrient needs. IM8 is offering an exclusive 10% off your first order with a free welcome kit when you enter the promo code SIMON at checkout on im8health.com. IM8 ships to 27 countries including the U.S., Canada, the U.K., Australia, and many regions across Europe, Asia, and South America. Pique Tea Pique’s Pu’er Tea Duo brings ancient fermentation into a simple daily ritual, delivering living nutrients that support digestion, metabolism, and sustained energy from the inside out. Unlock 20% off and establish your powerful foundation for sustained well-being at Piquelife.com/SIMON. Pique ships within the U.S. and to Australia, Canada, and select EU countries. Function Health Take charge of your health with advanced blood testing and personalised insights. Function Health offers a practical way to track key health markers such as cholesterol, blood sugar, and more. Learn more and join at functionhealth.com/simonhill for a $25 credit toward your membership. Only available to those living in the United States. Function Health ships to 48 U.S. states, excluding Rhode Island, Hawai‘i, and Puerto Rico. Simon Hill, MSc, BSc (Hons) Creator of theproof.com Host of The Proof with Simon Hill Author of The Proof is in the Plants Subscribe & Connect: YouTube Apple Podcasts Spotify Instagram: @simonhill Twitter: @theproof Facebook: The Proof with Simon Hill