I do not enjoy pure water fasts. I get cold, cranky, and useless by mid afternoon. The Olive Oil + MCT Fast is the version I actually stick to: a fasting day where the only thing you take in is small doses of good extra virgin olive oil and C8 MCT oil, plus water, tea, or black coffee.
The idea is simple. Your digestion gets a real rest because there is no food to break down, but you are not running on fumes. The MCT converts quickly into ketones, so your brain has fuel, and the olive oil brings polyphenols along for the ride. I use this as day 2 of my own gut reset week, and for me it is the difference between a fasting day I dread and one I almost look forward to.
What I think is going on (honestly, hedged)
The theory behind this fast is that the fasting window and the olive oil polyphenols nudge the body toward its own cleanup and repair processes, while the ketones from MCT keep energy steady instead of crashing. Resting digestion for a day also gives the gut lining a break, which is the part I care about most. I am not a doctor and I will not promise you autophagy on a schedule or an inflammation number going down. I can tell you this style of fasting day left me clearer and calmer than skipping food cold turkey ever did. If you have a medical condition, are pregnant, or are on medication, talk to your doctor before fasting at all.
The method, step by step
The night before
- Balanced dinner: light and simple, with protein (fish, chicken, or eggs), cooked vegetables, and olive oil.
- Stop eating at least 3 hours before bed so the fast starts on its own overnight.
Morning (start window)
- 1-2 tsp EVOO, the good stuff, early-harvest and polyphenol-rich if you can get it
- 1 tsp C8 MCT (C8 is the type that converts to ketones fastest)
- A large glass of water with a pinch of sea salt for electrolytes
Through the day (micro-doses)
- Repeat every 2 to 3 hours, aiming for 2 to 5 rounds: 1-2 tsp EVOO plus 1/2 to 1 tsp C8 MCT
- Water, herbal tea, or black coffee are all fine all day
- Light movement only: walking, stretching, sauna. No heavy training on fast day.
Total intake for the day
- EVOO: 6 to 8 tsp total (roughly 240-320 kcal)
- MCT: 2 to 4 tsp total, which keeps energy smooth
What the day feels like
- 0-12 hours: mild hunger waves. Salted water and a short walk get me through them every time.
- 12-24 hours: focus clears up and mood lightens. Keep drinking water.
- 20-30 hours: calm, steady energy, ketones doing the work.
Where it sits in the 7-day reset
This fast is day 2 of the gut reset week I run for myself. The full shape of the week:
| Day | Focus | What to Do |
| 1 | Prime | Simple meals: cooked vegetables, fish/eggs, olive oil |
| 2 | OO + MCT Fast | Follow the micro-dose schedule + electrolytes |
| 3 | Refeed & Repair | Broth, then avocado/eggs, then protein + veg + small starch |
| 4-5 | Build | Add ferments + greens |
| 6 | Flex | Add raw veg, cooled starches |
| 7 | Stabilize | Classic Dish by David plate (protein + double veg + olive oil) |
The refeed matters more than the fast
Coming off the fast gently is the part people rush and regret. Do it in this order:
- Start with warm bone broth (8-12 oz) plus 1 tsp EVOO.
- Then half an avocado with salt, or 2 soft eggs with EVOO.
- Lunch: fish or chicken, cooked vegetables, EVOO, and a small starch (rice, potato, squash).
- Dinner: similar to lunch. If you are gout-prone, skip alcohol during the refeed. I learned that one the hard way.
Troubleshooting
| Problem | Fix |
|---|---|
| Nausea | Halve the MCT dose or sip slower |
| Headache or fatigue | Add 1/4 tsp salt to your water and drink more fluids |
| Loose stools | Reduce MCT and space the doses out |
| Gout-prone | More water and electrolytes, no alcohol during refeed |
If gut repair is why you’re here
This fast is one day out of the process I used to rebuild my own gut. The Fermented Gut Reset is the whole thing laid out in order, so you are following a structure instead of piecing it together from blog posts.
