Time-Restricted Eating

Time-restricted eating (also called intermittent fasting) is about when you eat, not what you eat. The health benefits come from spending sufficient time in a fasted state—allowing the body to shift into repair and cleanup mode.

How It Works

Fed vs. Fasted State

State	What’s Happening
Fed	Blood glucose up, insulin up, digestion active, growth mode
Fasted	Blood glucose down, glucagon up, autophagy active, repair mode

The transition takes time. Even after your last bite, you remain in a “fed state” for 5-6 hours as digestion continues.

Hormones of Fasting

Hormone	Effect in Fasting
Insulin	Drops (allows fat burning)
Glucagon	Rises (mobilizes energy stores)
GLP-1	Rises (involved in fat mobilization)
Growth hormone	Rises (promotes repair)

The Core Protocol

Two Non-Negotiables

No food for 1+ hours after waking
No food for 2-3 hours before bed

These anchor your eating window to sleep-based fasting and maximize time in the fasted state.

Feeding Window Options

Window	Fasting Hours	Notes
8 hours	16 hours fasted	Most common, well-studied
6 hours	18 hours fasted	More benefits, harder to maintain
4 hours	20 hours fasted	Maximum benefits, very restrictive

“It pays off in the metabolic sense and in the health sense to not ingest any food in the first hour after waking.” — Effects of Fasting on Fat Loss & Health

Ideal Timing (Theoretically)

The “perfect” window would be middle of the day (e.g., 11am-7pm):

Attached to sleep-based fasting
Allows full nighttime fasting
Maximum time in fasted state

But this isn’t practical for most people. The best schedule is one you can maintain.

Benefits

Weight/Fat Loss

Creates caloric deficit naturally
Enhances fat oxidation
Lowers insulin (promotes fat burning)

Autophagy

“Self-eating” process that cleans up damaged cells
Enhanced during fasted state
Occurs mainly during sleep but boosted by fasting

Metabolic Health

Improved insulin sensitivity
Better blood glucose regulation
Reduced inflammation markers

Gut Health

Gives digestive system time to rest
Supports gut lining repair
May improve microbiome diversity

What Breaks a Fast?

Substance	Breaks Fast?
Water	No
Black coffee	Technically no (minimal calories)
Tea (plain)	Technically no
Coffee with cream	Yes
Any calories	Yes
Artificial sweeteners	Debated (may trigger insulin)

For maximum benefit, stick to water, black coffee, or plain tea during fasting hours.

Accelerating the Transition

The fed-to-fasted transition normally takes 5-6 hours. You can speed it up:

Walking After Meals

A 20-30 minute walk after your last meal:

Clears blood glucose faster
Gets you into fasted state sooner
Simple, no cost

Glucose Disposal Agents

Agent	Notes
Berberine	OTC, similar to metformin, can cause headache if taken without carbs
Metformin	Prescription, powerful glucose clearing

Caution: These can cause hypoglycemia (low blood sugar). Not for everyone.

Continuous Glucose Monitors

Patch-based monitors (like Levels or Dexcom) show real-time glucose:

Learn how different foods affect you
See when you’ve entered fasted state
Optimize your eating window

Common Mistakes

Mistake	Why It’s Wrong
Eating right before bed	Disrupts sleep, wastes fasting opportunity
Eating immediately upon waking	Breaks sleep-based fast too early
Breaking fast with sugar	Spikes insulin, crashes later
Fasting too aggressively too fast	Unsustainable, may backfire
Ignoring hunger signals	Some hunger is okay; excessive hunger is not

Who Should Be Cautious

Athletes needing maximum muscle gain (may need more frequent protein)
People with eating disorder history
Pregnant or nursing women
Diabetics (work with doctor)
Those on medications requiring food