Eating more fibre but feeling more blocked, bloated or sluggish than ever? You’re not imagining it, and you’re definitely not alone.

This week Leanne and Susie explain why piling on more fibre so often backfires. It’s especially common if you’re in a calorie deficit or taking a GLP-1 medication like Ozempic or Mounjaro. Leanne breaks down the three types of fibre your gut actually needs and how each one works. She also explains why your lettuce, tomato and cucumber salad isn’t doing as much for your bowels as you think.

Then they dig into a brand-new JAMA Psychiatry trial that found cutting back on ultra-processed foods improved depression scores in just four weeks, and how it builds on Australia’s landmark SMILES trial. Plus there’s Leanne’s $7 supermarket pizza find, with an ingredient list she says she couldn’t beat at home. And a listener question has Leanne and Susie (rarely!) disagreeing: can peanut butter be your main fat?

In this episode:

• Why more fibre can make constipation worse, and the low and slow rule that fixes it
• The three types of fibre:
  • gel-forming fibre (psyllium, chia, oats, kiwifruit)
  • roughage (bran, wholegrains, skins left on)
  • fermentable fibre and resistant starch, which feed your gut bugs
• Why two kiwifruit a day is great, but not enough on its own
• Why the 20g of fibre in your protein bar isn’t the same as fibre from whole foods
• Susie’s gut tips for GLP-1 users: cooked veggies over salads, wheat bran vs oats, moving through the day, and eating little and often
• The new study on ultra-processed food and depression, and what the SMILES trial already showed us
• The La Napoli Wood Fired Margherita pizza from Woolworths: four simple ingredients and about 20g of protein per half pizza
• Peanut butter as your main fat: how much you need, and why Leanne and Susie land on different daily fat targets

Research mentioned:

• Chagwedera DN et al. Reducing Ultraprocessed Foods From the Diets of Patients With Depression: A Pilot Crossover Trial. JAMA Psychiatry, 2026.
• Jacka FN et al. A randomised controlled trial of dietary improvement for adults with major depression (the SMILES trial). BMC Medicine, 2017.

New episodes drop every Wednesday. If this one helped, send it to a friend who’s been battling a sluggish gut. A rating or review on Apple Podcasts or Spotify helps more people find the show.

Follow Leanne on Instagram @leannewardnutrition and Susie @susie_burrell.