The Proof with Simon Hill

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

I’m joined by Dr Robert Eckel to unpack why obesity is far more complex than a BMI number and why insulin resistance plays such a central role in cardiometabolic disease.

We discuss preclinical versus clinical obesity, fat distribution, metabolic risk, and what actually improves health outcomes beyond weight loss alone.

What We Cover

Why BMI is only a starting point

Preclinical versus clinical obesity explained

Why visceral fat matters more than total fat

How insulin resistance develops with excess body fat

Who may benefit most from weight loss interventions

GLP-1 therapies, benefits and open questions

A practical, evidence-based conversation that reframes how we think about obesity, risk and long term health.

Introduction (00:00)

Clinical vs Preclinical Obesity: How Should Obesity Be Defined? (05:21)

Why Is Obesity Difficult to Diagnose and Treat in Practice? (08:06)

How Genetics and Environment Influence Body Fat Gain (20:27)

What Is Insulin Resistance and Metabolic Syndrome? (32:23)

How Insulin Sensitivity Relates to Clinical Obesity (55:26)

Why Insulin Resistance Begins in Adipose Tissue (59:49)

Physiological vs Pathological Insulin Resistance Explained (01:04:47)

How Physical Activity Improves Insulin Sensitivity (01:10:46)

Family History, Genetics, and Cardiometabolic Risk (01:12:30)

Individualised Obesity Treatment Guidelines in Clinical Care (01:15:40)

How GLP-1 Receptor Agonists Are Used in Obesity Management (01:16:12)

What Is the Obesity Paradox in Cardiometabolic Disease? (01:22:01)

Future Projections for Obesity and Cardiometabolic Health (01:30:07)

Public Health Challenges in Preventing Excess Adiposity (01:40:23)

Practical Clinical Takeaways and Final Thoughts (01:44:15)

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.

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.

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.

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.

Fertility is not just about timing ovulation. In this episode, Dr Natalie Crawford explains how sleep, stress, insulin resistance, diet, toxins, supplements, and lifestyle choices influence egg and sperm quality, miscarriage risk, and fertility outcomes.

We cover fertility myths, evidence-based nutrition, supplements that matter, and when medical treatments like IVF or egg freezing make sense.

What We Cover

Sleep, inflammation, and hormone signalling

Insulin resistance and reproductive health

Strength training, stress, and metabolic resilience

Fertility nutrition and soy myths

Supplements that support fertility

Sex, ovulation timing, and common misconceptions

Fertility treatments and realistic expectations

A practical, compassionate, and science-driven conversation for anyone planning a pregnancy or struggling to conceive.

You can learn more from Dr Natalie Crawford by preordering her book The Fertility Formula at nataliecrawfordmd.com/book. You can also follow her on Instagram for ongoing fertility education, and listen to her podcast As a Woman.

Intro (00:00)

How Personal Loss Changed Medical Practice (03:34)

Infertility, Isolation, and the Power of Support Systems (11:32)

Fertility Is Not Luck: How Empowered Choices Shape Outcomes (16:03)

Common Fertility Myths and Misconceptions (21:31)

Sperm Health, Lifestyle, and Testosterone Risks (32:59)

Chronic Inflammation and Its Impact on Reproductive Health (42:50)

Egg Quality vs Age: What Really Drives Infertility (50:55)

Hidden Signs of Chronic Inflammation You Shouldn’t Ignore (01:01:22)

Tracking Your Menstrual Cycle as a Vital Health Sign (01:10:34)

Birth Control and Fertility Awareness (01:19:17)

Lifestyle Changes That Can Improve Natural Fertility (01:28:33)

Why Sleep Is Critical for Hormones, Fertility, and Metabolic Health (01:34:13)

Muscle Mass, Insulin Resistance, and Fertility Health (01:43:48)

How Food Influences Inflammation (01:53:33)

Supplements That Support Fertility and Egg Quality (02:05:56)

Fertility Supplement Red Flags (02:15:55)

Everyday Behavioral Toxins That Harm Fertility (02:29:46)

Common Fertility Myths Explained (02:36:19)

When to Consider Medical Interventions for Infertility (02:42:43)

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.

ProLon

Just in time for the new year, ProLon’s 5-Day Fasting Mimicking Diet offers a science-backed way to support metabolic health while still allowing you to eat. ProLon is offering The Proof listeners 15% off their 5-day nutrition program at ProLonLife.com.

Caraway Caraway’s cookware set is a favourite for a reason. It can save you up to $190 compared to buying items individually, and The Proof listeners can take an additional 10% off at CarawayHome.com or by using code THEPROOF at checkout. Caraway. Non-toxic cookware made modern.

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.

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

Could your gut microbiome influence how many calories you absorb from the same food? Karen Corbin explains the science behind energy absorption, faecal calorie loss, and why feeding your microbes may support metabolic health.

We also cover practical diet upgrades, the reality on probiotics, and where microbiome research is heading next, including metabolite signatures and gut–brain links.

What We Cover

How the microbiome may change calorie absorption and energy balance

Why fibre and resistant starch matter, and how to increase them

Where “lost” calories go, and what microbial biomass could mean

Probiotics vs prebiotics: what is worth your time and money

How fast microbiome changes can happen with diet

The future: metabolites, objective diet measures, and brain health research

Thanks for listening. If you enjoyed it, share the episode and subscribe for more evidence-based conversations.

You can keep up with Dr Karen Corbin’s latest research by connecting with her on LinkedIn and exploring her profile at the AdventHealth Research Institute.

Intro (00:00)

Can the Gut Microbiome Increase or Reduce Calorie Absorption? (01:02)

Karen Corbin’s Microbiome Research Journey in Nutrition Science (04:17)

New Microbiome Experiments That Could Change How We Eat (11:17)

Energy Balance Explained: Calories, Metabolism, and Weight Gain (18:28)

How Scientists Study the Gut Microbiome (29:19)

Is the Gut Microbiome Causing Obesity and Metabolic Disease? (38:54)

How Medications Like Metformin Affect the Gut Microbiome (43:31)

Can a High-Fiber Microbiome Diet Reduce Hunger and Cravings? (45:06)

Liver Fat, Type 2 Diabetes, and Metabolic Dysfunction Explained (50:44)

Best Diet and Nutrition Strategies for Fatty Liver Disease (56:01)

How Diet Changes the Gut Microbiome and Metabolism (1:02:27)

Probiotics vs Prebiotics: What Actually Improves Gut Health? (1:07:08)

GLP-1 Weight Loss Drugs and Their Effects on the Microbiome (1:13:07)

Gut Microbiome Metabolites and How They Impact Health (1:16:28)

Gut-Brain Connection: How the Microbiome Affects the Brain (1:21:57)

Future of Gut Microbiome Research and Personalized Nutrition (1:30:24)

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.

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

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.

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.

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 a one-dollar-per-month trial period at shopify.com/proof.

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.