What is the Dr. Boz Ratio?
Divide fasting glucose (mg/dL) by blood ketones (mmol/L). Branded materials sometimes cite bands above 80, 40–80, and below 40 — these are not validated clinical cutoffs.
Dr. Boz Ratio Calculator
The Dr. Boz Ratio divides fasting glucose (mg/dL) by blood ketones (mmol/L). It combines two readings into one number for optional tracking — not a diagnostic test of which fuel your body is burning.
How to use this
- Choose water-only or assisted fasting and pick your goal hours.
- Tap Start fast when you finish your last bite. When you reach your goal, we show how to break the fast with meal ideas.
- Stage labels mark educational time windows only — they do not prove biological processes occurred.
Optional: Dr. Boz Ratio (glucose ÷ ketones)
Formula: glucose (mg/dL) ÷ ketones (mmol/L). Interpretations are educational only — not diagnostic targets. See our ratio guide for limitations.
Breaking an extended fast (19–35h)
After a longer fast, your digestive system may need a gentle restart. Start with protein, fat, and fiber in a moderate portion — not a feast.
How to break your fast
- 1Optional first: warm bouillon or bone broth — especially after water-only fasts.
- 2First meal: protein-forward and low carb. Aim for ~15–25g protein with healthy fat.
- 3Include gentle fiber: leafy greens, cucumber, or broccoli — not a huge raw salad right away.
- 4Eat slowly and stop at comfortable fullness — your hunger signals may be sharper than usual.
- 5Resume your normal low-carb eating window. Skip dessert and processed carbs for this first meal.
What to avoid
- • Breaking your fast with fruit juice, smoothies with banana, or sugary yogurt.
- • Large portions — treat this like two small meals 30 minutes apart if needed.
- • Heavy cream coffee with sugar — black coffee or tea is fine if you already tolerate it.
Tips
- A moderate protein-and-fat meal with gentle fiber is a common refeed pattern after longer fasts.
- If you feel lightheaded before eating, a small amount of broth or water may help — seek care if symptoms persist.
- Optional glucose/ketone tracking after eating is for personal observation only; it is not a diagnostic test.
Suggested break-fast meals
All recipesbreakfast
Scrambled Eggs with Spinach
Quick high-protein breakfast with minimal net carbs. Blood-sugar-friendly start for keto and insulin resistance meal plans.
~2g net carbs · 18g protein
lunch
Chicken Salad Lettuce Cups
Creamy chicken salad served in crisp lettuce wraps — low carb, high protein, no bread required.
~3g net carbs · 28g protein
dinner
Baked Salmon with Broccoli
Simple sheet-pan style dinner rich in omega-3s and protein with about 6g net carbs per plate.
~6g net carbs · 34g protein
breakfast
Low Carb Egg Muffins
Make-ahead egg cups with cheese and veggies — grab-and-go breakfast for busy mornings.
~2g net carbs · 12g protein
lunch
Ginger Chicken Bone Broth Soup
Light refeed soup with collagen-rich broth, shredded chicken, and ginger — about 3g net carbs. Gentle option after assisted fasting.
~3g net carbs · 18g protein
Not medical advice. This timer tracks clock time only. Talk to your doctor before fasting — especially on diabetes, blood pressure, or kidney medications. Do not adjust medication on your own.
Fasting timer
How to interpret your ratio
Branded materials sometimes cite bands above 80, 40–80, and below 40. Published clinical guidelines do not validate these as treatment thresholds. A single reading does not prove health status, autophagy, or metabolic flexibility.
Full explanation in our Dr. Boz ratio guide. Trends over days matter more than a single reading — if you track at all.
You need a dual glucose/ketone meter
The ratio requires finger-stick readings from a meter that reports both values. No meter? Use the net carb calculator and fasting clock without ratio tracking — you can still make progress.
What this calculator does not do
It does not advise tighter carbs, longer fasting, medication changes, or autophagy claims. Unexpected glucose or ketone results should be assessed with your care plan, especially with diabetes, illness, or pregnancy.
Related guides
Frequently asked questions
When should I check my ratio?
Many people check in the morning before breaking a fast, or at consistent intervals if they already use a dual meter. Use the same meter and conditions for trend comparison.
Is this medical advice?
No. The ratio is an optional educational tool. Work with your doctor if you manage diabetes or take glucose-lowering medications. Do not adjust medication based on the ratio.
Other calculators
Metabolic Low Carb Calculator · https://metaboliclowcarb.com