Protein Sparing Modified Fasting for Autophagy & Fat Loss with Vanessa Spina

In this episode, Dr. David Jockers sits down with Vanessa Spina, sports nutrition specialist, bestselling author of Keto Essentials, creator of the Tone ketone breath analyzer, and host of the Optimal Protein Podcast, for a deep dive on a groundbreaking new study out of the University of Nottingham, published in Clinical Nutrition in August 2025.

You will learn why the old "you can only absorb 30 grams of protein per meal" rule doesn't hold up, what really happens to protein you eat beyond that amount, and why the popular anabolic-window advice to slam a shake right after your workout is largely a myth. Dr. Jockers and Vanessa then break down a randomized, controlled fasting-mimicking diet study that overturns the long-held belief that high protein blocks autophagy, and explain why a high-protein, calorie-restricted approach can outperform a low-protein one for visceral fat loss, ketone production, and metabolic health.

They close with a practical, hour-by-hour walkthrough of the protein-sparing modified fast (PSMF): what to eat, how much protein to target, how to structure refeed days, and how it compares to water fasting and Ozempic for appetite control.

In This Episode:

00:00 Protein Absorption Myth

00:14 Episode Intro and Study Teaser

05:29 Meet Vanessa and Study Setup

07:35 100g Protein Study Breakdown

12:17 Protein Timing and Real Life

17:48 Protein First for Satiety

23:55 Ketones and High Protein Keto

28:10 Stress Hormones and Growth Hormone