The Proof with Simon Hill

The peptide and GLP-1 conversation has reached a fever pitch. Growth-hormone-releasing peptides are being marketed as longevity tools, GLP-1s are being treated as a default rather than a last resort, and a wellness aesthetic of higher IGF-1, more muscle, and less fat is being sold as the route to a longer life. In this episode, I sit down with Dr Valter Longo, Professor of Gerontology at USC and Director of the USC Longevity Institute, to look at what the data actually says.

Valter developed the Fasting-Mimicking Diet, has led foundational work on the growth hormone, IGF-1, insulin, and TOR axis across yeast, mice, and humans, and runs non-profit longevity foundation clinics in Europe and the US. He calls himself the anti-biohacker and makes the case using the totality of evidence rather than the loudest claim.

What we cover:

The peptide boom and why every line of evidence cuts the other way

The body composition reality of GLP-1s after 3 to 4 years

The optimal IGF-1 range and how to land there with food and timing

The Fasting-Mimicking Diet across more than 47 clinical trials, including the biological-age reduction studies

The Harvard plant-versus-animal protein data, properly read

A grounded case against ketogenic patterns for longevity and what to eat instead

If this conversation lands, a quick rating or review on Apple Podcasts or Spotify makes a real difference.

To follow more of Dr Valter Longo's work, visit his website, find him on Instagram, and explore the work of the Create Cures Foundation, the Valter Longo Foundation, the Longevity Technology Institute, and the European Longevity Institute through his published research and his book The Longevity Diet.

Intro (00:00)

The Peptide Boom and What Is Actually Being Sold (00:01)

GLP-1s: 92 Per Cent Drop-Out and the Body Composition Math (00:02)

The Fasting-Mimicking Diet Reverses Western-Diet Damage (00:13)

Snell, Ames, and Laron Dwarf Mice (00:18)

The Laron Syndrome Cohort in Ecuador (00:24)

Acromegaly and the Cost of High Growth Hormone (00:28)

The Optimal IGF-1 Range: 120 to 160 ng/mL (00:50)

Plant vs Animal Protein, Properly Read (00:57)

The Anti-Keto Case from Okinawa to Loma Linda (01:08)

Stanford Crohn's, Miami UC, and Rome Kidney Disease (01:22)

Biological Age Reduction After Three FMD Cycles (01:25)

FMD Safety Across More Than a Million Users (01:31)

The Longevity Diet: Eat More, Eat Better (01:43)

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.

38Tera ships to the United States, Australia, and New Zealand.

Pique

Pique’s Nandaka combines fermented Pu’er tea, full-spectrum Reishi, ceremonial cacao, and L-theanine for calm, sustained energy without the coffee crash. 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.

Truemed

Truemed helps qualified customers use pre-tax HSA or FSA dollars on health-related products like fitness, recovery, and sleep tools, often saving around 30% on average. Visit Truemed.com to see what qualifies. This is hands down the best way to make the most of your health dollars.

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, 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: @theproof

Twitter: @theproof

Facebook: The Proof with Simon Hill

Plant-based nutrition has rarely been more contested. Seed oils are vilified, butter is celebrated, protein is treated as a pure quantity question, and nutrition epidemiology is routinely dismissed by people who have never read one of its papers. In this episode, I sit down with Dr Andrea Glenn, an Assistant Professor at NYU and Visiting Scientist at the Harvard T.H. Chan School of Public Health, to look at what the strongest evidence actually shows.

We cover the recent plant-versus-animal protein data from the Nurses' Health Studies and Health Professionals Follow-up Study, the Portfolio Diet, the new CHEAP trial, the JAMA Internal Medicine butter and plant oil paper, and the new 2026 AHA dietary guidance.

What we cover:

The plant-to-animal protein ratio and its association with cardiovascular and coronary heart disease risk

The Portfolio Diet, what it contains, and how its LDL-lowering effects compare to a low-dose statin

Butter, beef tallow, tropical oils, and what the latest mortality data show

Why "low-carb" is not one diet, and why food sources matter as much as the macronutrient breakdown

A grounded defence of nutrition epidemiology and the role of food frequency questionnaires

Practical takeaways for how to eat in line with the new AHA guidance

This is the conversation I wanted to have for anyone tired of nutrition by hashtag. If it lands, a quick rating or review on Apple Podcasts or Spotify makes a real difference.

To follow more of Dr Andrea Glenn's work, find her on Instagram at instagram.com/andrea.glenn.rd, on X at x.com/andreaglennrd, and on LinkedIn at linkedin.com/in/andrea-glennrd.

Intro (00:00)

Plant vs Animal Protein Ratio and Heart Disease (01:17)

Does Total Protein Amount Also Affect CVD Risk? (05:33)

Why Nutrition Epidemiology Critics Often Get It Wrong (11:00)

Where Epidemiology Fits in the Evidence Hierarchy (17:28)

Sensitivity Analyses: How Scientists Test Their Results (22:16)

What It's Like Doing Science at Harvard (28:55)

The Portfolio Diet: Origins and the Science Behind It (32:21)

The CHEAP Trial: Testing Portfolio Diet Long-Term (41:03)

Portfolio Diet in Cohort Studies: What the Data Shows (50:24)

Unsaturated Fats: Are They Inherently Heart-Protective? (56:16)

Phytosterol Supplements: LDL Benefits vs Safety Questions (01:00:06)

Butter vs Plant Oils: What Mortality Data Actually Shows (01:06:57)

Plant vs Animal MUFAs and Type 2 Diabetes Risk (01:12:11)

Low-Carb Diet Quality and Diabetes Risk: New Data (01:15:37)

2026 AHA Dietary Guidelines: Key Differences Explained (01:20:23)

Portfolio Diet's Potential to Reduce Disease Burden (01:26:35)

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.

LMNT

Stay hydrated with LMNT. Get a free Sample Pack of LMNT’s most popular drink mix flavours with any purchase at DrinkLMNT.com/SIMON Find your favourite LMNT flavour, or share with a friend. And if you don’t like it? Full refund, no questions asked.

LMNT ships to the U.S. and Canada, with sparkling flavors available only in the contiguous U.S.

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.

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.

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.

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

Ultra-processed foods are now the central nutrition conversation of the decade, but the gap between the marketing and the evidence has never been wider. In this episode, I sit down with registered nutritionist and Sunday Times bestselling author Rhiannon Lambert to bring some practical clarity to what the science actually says.

We get into how the NOVA system can be too blunt to be useful, why calorie counts on packets are often 30 to 40 per cent inaccurate, what the most recent UPF and cancer data actually shows, and how to spot the difference between sensible fortification and the additives that are genuinely worth questioning.

What we cover:

What ultra-processed foods really are, and why the NOVA category is so blunt

The food matrix and why calorie labels can be misleading

UPFs, cancer risk, and the UCL home-cooking study

The UK colourings linked to hyperactivity, MSG, and artificial sweeteners

How to read a label in under thirty seconds

Practical strategies for cooking more at home, even on a budget

This is a conversation about reclaiming the kitchen without falling into purism. If it lands, a quick rating or review on Apple Podcasts or Spotify makes a real difference.

To learn more from Rhiannon Lambert, visit her clinic at rhitrition.com, follow her on Instagram at instagram.com/rhitrition and TikTok at tiktok.com/@rhitrition, and pick up her books, The Unprocessed Plate **and The Fibre Formula. You can also find her co-hosting The Wellness Scoop podcast with Ella Mills.

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.

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.

ProLon

ProLon’s 5-Day Fasting Mimicking Diet is a science-backed, plant-based program designed to support metabolic health while keeping your body in a fasting-like state. Get 15% off sitewide plus a $40 bonus gift at ProLonLife.com.

ProLon ships within the United States.

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.

HomeServe

HomeServe helps protect your home from unexpected repair costs, covering things like plumbing, electrical, and HVAC issues that standard insurance often doesn’t include. With 24/7 support and access to local contractors, it takes the stress out of urgent repairs. Plans start from $4.99 a month at HomeServe.com.

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

Peptides are being marketed as solutions for everything from injury recovery to longevity, but what does the science actually say?

In this episode, Dr Leigh Baxt joins me to break down what peptides are, how drug development really works, and why so many of the claims circulating online are running far ahead of the evidence. We explore the difference between approved peptide medicines and unregulated products sold online, why anecdotes are not enough, and what people should understand before putting these compounds into their bodies.

What We Cover

What peptides are and why they are not new

FDA-approved peptide drugs versus unregulated peptides sold online

Why scientists are concerned about the current peptide boom

How drugs are developed and why most ideas fail

Why animal and cell studies are not enough to establish safety and efficacy

The problem with using “natural” as a proxy for safe

How to think critically about peptide marketing and anecdotal claims

This is an important conversation for anyone trying to make sense of the peptide boom and separate genuine science from wellness hype.

To learn more from Dr Leigh Baxt, follow her on Instagram at @sciencemomscicomm. I also recommend exploring Unbiased Science, where science communication is made far more accessible for the public. You can follow the project on Instagram, Threads, Facebook, LinkedIn, X, subscribe on Substack, and watch on YouTube.

The views expressed are her own and she is not representing her employer.

Intro (00:00)

Stanford Expert Breaks Down the Peptide Hype (00:53)

The Skill Set Behind Real Drug Development (05:09)

FDA Approved vs Research Only Peptides Explained (08:03)

Why Most Drug Candidates Never Become Medicine (11:06)

Peptide Reclassification What Changes and What Doesn't (15:59)

The Biological Risks Nobody Mentions About Peptides (20:36)

Why Natural Peptides Are Not Necessarily Safe (23:00)

What Safety Tests Drugs Must Pass First (28:51)

Accepting Unknown Risk What That Actually Means (33:31)

How to Find Credible Health Experts Online (36:13)

Why Drug Development Always Requires A Team (39:19)

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.

Cozy Earth

Cozy Earth’s sheets are designed to keep you cool by wicking heat and moisture away from your body, helping you sleep deeper and wake less. Get up to 20% off at cozyearth.com with code THEPROOF.

Cozy Earth ships worldwide.

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.

ProLon

Ready for your own reset? For a limited time, ProLon is offering The Proof listeners 15% off sitewide plus a $40 bonus gift when you subscribe to their 5-Day Program. Visit ProLonLife.com to claim your discount and bonus gift.

ProLon ships within the United States.

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

In this episode, I’m joined by Dr Belinda Beck to challenge long-held beliefs about osteoporosis and bone health. We break down what actually works, what doesn’t, and why many people are being given outdated advice.

We explore the science of bone adaptation, the importance of heavy resistance training, and how to think about prevention and treatment across the lifespan.

What We Cover

Why walking is not enough for bone health

How heavy lifting changes bone strength

What DEXA scans can and cannot tell you

The impact of menopause on bone loss

Exercise vs medication for osteoporosis

Common myths and misleading advice

If you want to better understand how to build and protect your bones, this episode is a must-listen.

You can learn more about Dr Belinda Beck’s work via her website, follow updates on Facebook, or explore her clinical and training work at The Bone Clinic and ONERO.

Intro (00:00:00)

Why Your Doctor Is Wrong About Bone Exercise (00:01:44)

The Silent Fracture Crisis No One Is Catching (00:08:34)

How Much of Bone Loss Can You Actually Control? (00:14:23)

Why Your DEXA Score Misses the Bigger Picture (00:17:28)

What Blood Tests Actually Reveal About Your Bones (00:24:58)

The Trial That Changed Osteoporosis Exercise Guidelines (00:30:00)

The Exact Load Needed to Rebuild Bone (00:38:31)

Why Static Holds Won't Build Your Bones (00:43:47)

Strength Training Cuts Fracture Risk by 78% (00:47:57)

Why Osteoporosis Guidelines Are Still Getting It Wrong (00:51:03)

Should You Combine Bone Meds With Heavy Training? (00:55:45)

More Exercise + Meds = Better Bone Outcomes (01:02:47)

How Menopause Destroys Bone (And What Fights Back) (01:06:35)

The Hidden Bone Risk of GLP-1 Weight Loss Drugs (01:11:05)

Bone Gadgets and Gimmicks: What the Science Says (01:14:01)

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.

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.

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 PROOF at checkout. Caraway. Non-toxic cookware made modern.

Caraway ships within the United States.

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