The Proof with Simon Hill

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:

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Instagram: @simonhill

Twitter: @theproof

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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

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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.

In this episode, Drew Harrisberg and I go deep on life beyond macros and metrics. We talk about gratitude, regret, ageing, and how constant optimisation can quietly pull us away from what actually matters.

We also cover living with type 1 diabetes, health tech, social sport, future wellness trends, and why simplicity, connection, and play may be the real foundations of long-term wellbeing.

What We Cover

Optimisation culture versus presence and joy

Regret, legacy, and end-of-life reflections

Health data, CGMs, and the mental load of tracking

Type 1 diabetes and daily decision fatigue

Paddle, play, and the power of social movement

Where wellness trends may be heading next

A thoughtful, wide-ranging conversation on health, meaning, and living well.

To connect with Drew, you can reach him via his Instagram or website, Drew’s Daily Dose, where you can also find his training program. To hear more from Drew, check out his previous episodes on The Proof.

Intro (00:00)

Dietary Changes and Reflections (03:18)

Insulin Sensitivity, Dietary Fat, and Metabolic Health (10:25)

Bone Health and Exercise in Older Adults (14:56)

Protein Intake, Leucine, and Muscle Protein Synthesis (32:15)

Controlled Studies vs. Real-World Results (38:24)

How Older Adults Should Optimize Protein Intake (45:13)

Ethical and Environmental Trade-Offs of Plant-Based Diets (57:10)

Reflecting on Life, Priorities, & Regrets (01:10:15)

The Ideal Self vs the “Ought” Self (01:17:27)

Struggles with Distraction and Presence (01:24:50)

The Future of Longevity Retreats (01:37:44)

The Over-Optimization Trap in Health and Life (01:45:08)

Why Upcoming Dietary Guidelines May Spark Controversy (01:48:46)

Will America’s Obesity Rates Finally Decline? (01:58:30)

Music, Creativity, and Personal Challenges (02:04:31)

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.

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.

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.

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

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.

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.

I sit down with Dr Luc van Loon to unpack what really happens to protein in the body, from digestion to muscle and organ tissue. We explore why muscle protein synthesis is often misunderstood, how inactivity drives muscle loss, and what the research actually says about protein needs across the lifespan.

What We Cover

Ice baths and their impact on muscle adaptation

Protein absorption, muscle protein synthesis, and common myths

Anabolic resistance and the role of physical activity

Protein needs in ageing, illness, and recovery

Plant based versus omnivorous diets and muscle health

A deep dive into protein science, ageing, and what matters most for preserving muscle and function.

Intro (00:00)

How Protein Research Evolved in Exercise Physiology (02:07)

How Muscle Protein Synthesis Actually Works (Mechanisms Explained) (04:01)

Tracing Amino Acids From Food Into Muscle Tissue (07:00)

Biggest Myths About Protein Intake (What the Public Gets Wrong) (10:02)

Protein Digestion, Absorption, and Where Amino Acids Go (17:25)

Anabolic Resistance Explained: Why Muscle Response Declines With Age (38:16)

How Much Protein Do You Really Need? Optimal vs Adequate Intake (46:41)

How Protein Digestion Studies Are Designed (And Their Limitations) (53:22)

Omnivore vs Vegan Diets: Muscle Protein Synthesis Compared (1:00:12)

Protein Quality vs Quantity: What Actually Builds Muscle (01:08:52)

Protein Powders, Isolates, and Supplements: Do They Help? (01:11:08)

Protein Requirements (01:15:08)

IGF1, Protein Consumption and Cancer (01:16:32)

Amino Acids Explained: How the Body Rebuilds Protein From Steak (01:22:34)

Anabolic Response Explained: When Amino Acids Actually Build Muscle (01:28:59)

Supplements and Muscle Protein Synthesis (01:30:35)

Muscle Protein Turnover, Aging, and Preventing Muscle Loss (01:38:59)

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.

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.

Pique Tea

Pique's Nandaka provides sustainable, all-day energy and makes you feel like you’re doing something good for your body! Try Pique and get 20% off FOR LIFE when you shop exclusively at Piquelife.com/simon.

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.

In Part 2 of Highlights of 2025, I revisit some of the most important conversations from the year on The Proof, covering cardiovascular prevention, blood pressure, cholesterol, nutrition, sustainability, and performance.

Featuring insights from Dr Laurence Sperling, Dr Thomas Dayspring, Dr Dan Soffer, Dr Raymond Townsend, Dr Hannah Ritchie, Dr Iñigo San Millán, and Dr Dawn Mussallem, this episode focuses on evidence-based strategies for reducing long-term risk and improving healthspan.

What we cover:

LDL cholesterol and ApoB targets for prevention and regression

Blood pressure, ageing, and lifestyle interventions

Lp(a) risk and emerging therapies

Diet quality, sustainability, and realistic dietary swaps

Soy, breast cancer outcomes, and plant protein

Creatine dosing, safety, and performance benefits

If you want a clear-eyed, evidence-based look at heart health and longevity, this episode pulls it all together.

Intro (00:00)

Optimal LDL & Blood Pressure Levels to Prevent Heart Disease - Dr Laurence Sperling (01:13)

Keto Diet, Cholesterol & Heart Health Explained - Simon Hill (11:19)

Why Heart Disease Happens Even When You’re Doing Everything Right - Dr Thomas Dayspring and Dr Dan Soffer (29:07)

Who Should Start Statins or Cholesterol-Lowering Therapy - Dr Thomas Dayspring and Dr Dan Soffer (53:28)

What Hypertension Really Means and Why It’s Misunderstood - Dr Raymond Townsend (1:08:20)

Lifestyle Habits That Naturally Lower Blood Pressure - Dr Raymond Townsend (1:20:28)

Can You Lower Lipoprotein(a) or Is It Genetic - Simon Hill (1:27:37)

Plant-Based Diets, Nutrition Needs & Climate Impact - Dr Hannah Ritchie (1:32:05)

Lactate, Mitochondria & Longevity - Dr Iñigo San Millán (1:45:48)

The Biggest Healthy Eating Questions in Cancer Prevention - Dr Dawn Mussallem (1:57:29)

Creatine Benefits, Safety & Performance - Simon Hill (2:05:07)

Does Creatine Timing Matter - Simon Hill (2:11:40)

Does Creatine Harm the Kidneys - Simon Hill (2:13:58)

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.

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.

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.

Pique Tea

Pique's Nandaka provides sustainable, all-day energy and makes you feel like you’re doing something good for your body! Try Pique and get 20% off FOR LIFE when you shop exclusively at Piquelife.com/simon.

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 $400 off at eightsleep.com/theproof. Try it risk-free for 30 days, with worldwide shipping.

Subscribe & Connect:

YouTube

Apple Podcasts

Spotify

Instagram: @simonhill

Twitter: @theproof

Facebook: The Proof with Simon Hill