mikevenasse.com · Nutrition
The Science of
When Not to Eat
What you eat matters enormously. When you eat matters just as much. These guides cut through the noise on fasting — what actually works, what doesn't, and where to start.
Choose Your Approach
The Overnight Fast
Finish dinner by 7–8pm. Don't eat until 7–8am. That's it. 12 hours of fasting activates autophagy and metabolic reset without any discomfort.
16:8 Method
Eat within an 8-hour window, fast for 16. Most people do 12pm–8pm. The most researched fasting protocol with the strongest evidence base.
5:2 Protocol
Eat normally 5 days. Eat just 500–600 calories on 2 non-consecutive days. Excellent for metabolic flexibility and sustainable weight management.
24-Hour Reset
One complete fast per month. Powerful autophagy stimulus. Should only be attempted after comfortable with 16:8. Always consult your doctor first.
Exercise Fasted
Training in a fasted state — particularly morning workouts — amplifies fat adaptation and growth hormone release. Not for everyone.
Caloric Restriction
Eating 15–30% fewer calories than maintenance. The most consistent longevity intervention in animal studies. Challenging but effective.
What Happens in Your Body When You Fast
0–4 Hours: Digestion
Your body is processing your last meal. Blood glucose is elevated, insulin is high, and your body is running primarily on glucose. No fasting benefits yet.
4–12 Hours: Transition
Blood glucose normalises. Insulin drops. Your body begins shifting toward fat oxidation. Glycogen stores in the liver start depleting. You begin producing ketones.
12–16 Hours: Autophagy Begins
This is the longevity sweet spot. Autophagy — cellular self-cleaning — activates significantly around the 12-14 hour mark. Your cells begin dismantling and recycling damaged proteins and organelles. This is why the overnight fast is Mike's minimum recommendation for everyone.
16–24 Hours: Deep Fasting
Autophagy continues to intensify. Human growth hormone rises dramatically (up to 5x baseline at 24 hours). Fat oxidation is maximised. This is the territory of 16:8 and beyond.
Common Fasting Mistakes
- Breaking the fast with sugar — this causes a massive insulin spike after a fasted state. Break your fast with protein and fat first.
- Not drinking enough water — mild dehydration makes fasting feel much harder. Drink 2–3L during your fasting window.
- Fasting too aggressively too soon — start with 12 hours and extend slowly. Jumping straight to 20 hours creates unsustainable hunger.
- Women fasting the same as men — women are more sensitive to fasting signals. 14 hours is typically the optimal window for women.
Start Your First Fast Tonight
Get Mike's free beginner fasting guide — a simple 4-week ramp-up plan that takes you from 12 to 16 hours comfortably, without hunger or energy crashes.
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