Net carbs are total carbohydrates minus fiber and often sugar alcohols. Keto and low-carb diets use them to track daily carb intake.

Is this medical advice?

No. These calculators provide estimates for education only. Work with your healthcare provider — especially if you have diabetes, take insulin, or manage blood pressure medications.

How long should I fast?

Dr. Mindy Pelz starts most people at 13–16 hours. Autophagy benefits increase around 17 hours. Extended 24–72 hour fasts need medical awareness — especially on medications.

Which calculator should I use first?

Use the net carb calculator when reading a food label. Use the macro calculator for daily targets. Use the fasting clock when you are ready to track fasts after low-carb eating feels stable.

Fasting · 7 min read

Electrolytes During Fasting — Sodium, Potassium & Magnesium

Prevent headaches and cramps during 16–72 hour fasts. Dr. Westman bouillon and Dr. Boz assisted-fasting tips.

Try the tool

Extended fasting clock →

Why electrolytes drop

Low insulin during fasting increases sodium loss through kidneys. Without replacement, you may get headaches, dizziness, or leg cramps — often mistaken for “fasting not working.”

What experts recommend

Dr. Westman: bouillon or broth for sodium (assisted fasts)
Dr. Boz: salt water, magnesium, potassium as needed — avoid caloric broth on strict water-only
Plain water-only beyond 24h increases electrolyte risk — switch to assisted mode

Frequently asked questions

Can I use zero-calorie electrolyte powders?

Many assisted fasters use sugar-free electrolyte mixes. Check labels for carbs and artificial sweeteners if you are strict keto.

Fasting

Water Fast vs Assisted Fast — Electrolytes Explained

Strict water-only fasting vs assisted fasting with salt, bouillon, and electrolytes. Guidance from Dr. Westman and Dr. Boz for safe extended fasts.

6 min read

Fasting

How to Break a 24-Hour Fast Safely

Step-by-step guide to refeeding after a 24-hour gut-reset fast. What to eat first, what to avoid, and when to seek medical help.

7 min read

Metabolic Low Carb Calculator provides educational content only — not medical advice, diagnosis, or treatment. Talk to your healthcare provider before changing diet, fasting, or medications. Read disclaimer