I’ve read your books and followed intermittent fasting for several years, often doing 20-, 24-, and occasionally 72-hour fasts. During that period, I mainly did cardio, bootcamp classes, and bodyweight training, and fasting worked very well for me.
Recently, I transitioned to progressive overload resistance training. What I’m noticing is that fasting suddenly feels incompatible with the demands of the workouts. Recovery, performance, and hunger signals make it very difficult to maintain long fasting periods. Adequate food intake throughout the day, especially around workouts, seems necessary.
It made me wonder whether the metabolic demands of progressive overload fundamentally change the equation.
Would you consider writing about how progressive overload and hypertrophy training interact with intermittent fasting? Specifically:
• Does progressive overload increase the need for more frequent protein intake?
• At what point does fasting begin to compromise recovery or muscle growth?
• Is fasting still appropriate for people training for hypertrophy rather than fat loss?
Many people who follow your work are transitioning from metabolic health goals into strength training, especially those of us in our 50s who want to maintain bone density, and I think this topic would be extremely helpful.
I appreciate your writings and perspective. I think there are a few other factors at play though, that I’d love to see you explore. Seed oils are a big one I think, as well as environmental toxins. Definitely true that people are eating way more often and I know that’s important, just maybe not the whole picture.
Fung's point about insulin being the driver rather than calories is something I didn't really believe until I started tracking my own fasting glucose alongside my eating windows. Dropped from a 16:8 to OMAD three days a week and my morning readings went from 95 to low 80s within a month. The hormonal piece is honestly what makes keto and fasting work so well together — lower insulin from both angles.
Fung's point about insulin being the driver rather than calories is something I didn't fully get until I started tracking my own blood glucose alongside my meals. Once I went keto and added a 16:8 fasting window, my fasting insulin dropped from 14 to 5 in about three months, and the weight loss became almost effortless after that. The hormonal framing just makes so much more sense than the "eat less move more" advice I got for years.
Thanks for an excellent summary of intermittent fasting. I try to eat during a 6-8 hour window every day, even when I don't eat the healthiest. When I do so, it's much easier to maintain a healthy weight.
Fung's point about insulin being the driver rather than calories is something I wish I'd understood years ago. I spent so long counting every calorie before keto and fasting finally clicked for me - once I stopped snacking between meals and let insulin actually drop, the weight started moving without all the obsessive tracking.
Fung's point about insulin being the main driver rather than calories lines up with what I've seen doing keto for three years now. I can eat way more calories than my old low-fat diet and still lose fat, as long as I keep insulin low. The hormonal framing honestly made everything click for me back when I first read The Obesity Code.
Dr. Fung,
I’ve read your books and followed intermittent fasting for several years, often doing 20-, 24-, and occasionally 72-hour fasts. During that period, I mainly did cardio, bootcamp classes, and bodyweight training, and fasting worked very well for me.
Recently, I transitioned to progressive overload resistance training. What I’m noticing is that fasting suddenly feels incompatible with the demands of the workouts. Recovery, performance, and hunger signals make it very difficult to maintain long fasting periods. Adequate food intake throughout the day, especially around workouts, seems necessary.
It made me wonder whether the metabolic demands of progressive overload fundamentally change the equation.
Would you consider writing about how progressive overload and hypertrophy training interact with intermittent fasting? Specifically:
• Does progressive overload increase the need for more frequent protein intake?
• At what point does fasting begin to compromise recovery or muscle growth?
• Is fasting still appropriate for people training for hypertrophy rather than fat loss?
Many people who follow your work are transitioning from metabolic health goals into strength training, especially those of us in our 50s who want to maintain bone density, and I think this topic would be extremely helpful.
Thank you for your work and your writing.
One of your greatest longtime fans,
Conchita
I appreciate your writings and perspective. I think there are a few other factors at play though, that I’d love to see you explore. Seed oils are a big one I think, as well as environmental toxins. Definitely true that people are eating way more often and I know that’s important, just maybe not the whole picture.
Fung's point about insulin being the driver rather than calories is something I didn't really believe until I started tracking my own fasting glucose alongside my eating windows. Dropped from a 16:8 to OMAD three days a week and my morning readings went from 95 to low 80s within a month. The hormonal piece is honestly what makes keto and fasting work so well together — lower insulin from both angles.
Fung's point about insulin being the driver rather than calories is something I didn't fully get until I started tracking my own blood glucose alongside my meals. Once I went keto and added a 16:8 fasting window, my fasting insulin dropped from 14 to 5 in about three months, and the weight loss became almost effortless after that. The hormonal framing just makes so much more sense than the "eat less move more" advice I got for years.
Thanks for an excellent summary of intermittent fasting. I try to eat during a 6-8 hour window every day, even when I don't eat the healthiest. When I do so, it's much easier to maintain a healthy weight.
How can a layman reasonably check their insulin levels on a regular basis? As far as I know this is a blood test
Fung's point about insulin being the driver rather than calories is something I wish I'd understood years ago. I spent so long counting every calorie before keto and fasting finally clicked for me - once I stopped snacking between meals and let insulin actually drop, the weight started moving without all the obsessive tracking.
Fung's point about insulin being the main driver rather than calories lines up with what I've seen doing keto for three years now. I can eat way more calories than my old low-fat diet and still lose fat, as long as I keep insulin low. The hormonal framing honestly made everything click for me back when I first read The Obesity Code.
Currently doing Alternate Day Fasting. Feeling great! Thanks Dr. Fung.