Selected notes on Dr. Mindy Peltz’s fasting recommendations
Your weekly fasting rhythm
4 intermittent (16-24 hour) fasting days
These sustainable fasts support fat burning, ketosis, and moderate autophagy
- If eating dinner, do so before sunset or 2-3 hours before bed (better sleep and insulin control)
- Break the fast with ~30g protein (a chicken thigh plus egg, ¼” lb. burger, etc.)
- Prioritize protein, then veggies
2 nourishment days
Supports hormonal balance (including progesterone in women; even after menopause, you’re still producing small amounts)
- No fasting
- Add complex carbs
- Prioritize rest
1 flexible day
Eat however you want
Extended fast (optional)
48-72 hours quarterly (recommended) or monthly (at most)
Supports deep autophagy, stem cell activation, immune cell reboot, and growth hormone increase
- Timing
- Cycling women: Days 1-10 (higher estrogen, lower progesterone)
- All others: Choose low-stress, high-energy days
- Autophagy timeline
- Stage 1 @ 17 hours: liver cleanup
- Stage 2 @ 24 hours: broader cellular cleanup
- Stage 3 @ 48-72 hours: stem cell activation and immune reset
Rules during a fast
Include
- Water (plain, sparkling, or mineral)
- Electrolytes (salt, magnesium, potassium)
- Black coffee
- Plain tea
Avoid
- Food and broth
- Sugar or carbs (no milk or cream in drinks, no flavored electrolytes with citric acid/malic acid)
- Collagen, BCAAs, most supplements
Note: If fasting for fat-burning (not autophagy), tiny caloric additions—like a splash of milk or a squeeze of lemon—are fine
Why this works
Autophagy
- Meaning “self-eating,” autophagy is your body’s cellular cleanup mode
- When insulin is low for ∼16+ hours, your cells start hunting for damaged proteins, old mitochondria, and pathogens, wrapping and breaking them down. These are then recycled for energy or new cells
- Autophagy is linked to reduced cancer risk, better brain health, and less inflammation
Ketosis
- Ketosis is our fat burning mode
- Begins when the body produces ketones and liver glycogen drops, typically ∼12-16 hours into a fast
- Ketones suppress hunger, protect muscle, and fuel the brain
Weight loss
- Happens when insulin stays low for 14+ hours
Insulin sensitivity (the opposite of insulin resistance)
- Fasting triggers autophagy, which helps correct insulin resistance
- Aging and metabolic stress can increase insulin resistance in both men and women
- The decline in estrogen during menopause triggers insulin resistance by default
- HRT helps but isn’t enough on its own
- Fasting lowers insulin and activates autophagy, which helps correct insulin resistance