Hormones control almost every system in your body. They are like an orchestra playing, so when one instrument is a little off-key, it affects the whole system. If you feel tired, anxious, or are gaining weight, your hormones may be involved.

In this episode, leading reproductive expert Dr Helen O’Neill explains how hormone health affects fertility, metabolism, and mental health for both men and women. 

The core question is simple: if hormones run your body, how much influence do you have over them? 

Alongside ZOE’s head nutritionist, Dr Federica Amati, Helen explores the links between hormones and fatigue, anxiety, weight gain, fertility, and metabolic health. The episode covers thyroid health, chronic pain, sperm health, and why gut hormones play a central role in appetite and weight regulation. We also examine why some female-specific conditions remain misunderstood or undiagnosed, and how better data may help change that.

Most importantly, this episode focuses on what you can do to take back control. With emerging science suggesting that diet plays a key role in hormone regulation, you’ll hear how fibre, plant diversity, healthy fats, and key micronutrients support gut hormone production and fertility. You’ll also learn why changes made over three months may meaningfully influence fertility, and why conception is always a shared responsibility.

Help keep your hormones in tune with this guide to the relationship between gut, diet and hormones, produced in partnership with the hormone experts at Hertility.

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Timecodes

00:00 Intro

03:50 One hormone can change everything

09:50 Injecting testosterone can shut this down

12:30 You were born with all the eggs you’ll ever have

15:15 The subtle signs your hormones are off

17:55 The most common thyroid problem no one spots

20:30 ‘Balancing hormones’ — myth or medicine?

23:10 The condition affecting one in 10 women

25:40 Why PCOS impacts weight and mood

28:10 Why women were excluded from medical trials

30:25 The data breakthrough changing women’s health

32:30 The devastating disease that mimics cancer

35:15 It takes nine years to diagnose this

37:00 The symptom doctors often miss

39:15 Your gut is a hormone factory

41:00 As powerful as a drug?

43:00 The ‘gourmet meal’ your hormones love

44:05 The flash of zinc at fertilisation

46:15 A handful of walnuts improved sperm health

48:50 Your sperm affects your child’s future

50:30 The fertility habits that really matter

52:40 The biggest takeaway about hormones and food

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Free resources from ZOE

The Hormone Harmony Guide: Tuning Your Body’s Internal Orchestra

Eating for Better Brain Health: Your brain-gut blueprint

How to eat in 2026 - Discover ZOE’s 8 nutrition principles for long-term health

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Mentioned in today's episode

Hertility Health

Effect of Walnuts on Male Fertility, Current Developments in Nutrition (2019)

Sperm health and risk of nausea and vomiting during pregnancy, Nature (2023)

Interplay of Gut Microbiota in Polycystic Ovarian Syndrome, Pharmaceuticals (2023)

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Episode transcripts are available here.