You generally break your fast when either (a) your planned fasting window ends or (b) your body is clearly signaling that continuing would be unsafe or unreasonable for your situation. Because “when do I break my fast” can mean different things, here are the main angles.

1. By type of fasting

Intermittent fasting (16:8, 18:6, OMAD, etc.)

Most people break their fast when:

  • Their chosen eating window starts (for example, 12:00–20:00 for 16:8).
  • They’ve hit their set fasting hours (for example, 18 hours since last calorie intake).

You should definitely break your fast earlier if:

  • You feel faint, dizzy, confused, or shaky.
  • You have chest pain, shortness of breath, or a racing or irregular heartbeat.
  • You can’t concentrate or feel like you might pass out.

These are red-flag symptoms where continuing to fast is not worth the risk.

Religious fasting (e.g., Ramadan)

For Islamic fasting in Ramadan:

  • The fast is broken at sunset , after the call to Maghrib prayer.
  • It begins again at true dawn , usually tied to the Fajr prayer time.

If you’re sick, pregnant, breastfeeding, traveling, very elderly, or have a serious medical condition, religious rules often allow or require you to break the fast and make it up or compensate later—ask a trusted religious authority and your doctor.

Longer fasts (24+ hours, multi‑day fasts)

Most medically cautious guidance says you should break a prolonged fast if:

  • You have new or worsening weakness, dizziness, fainting, confusion, or vision changes.
  • You can’t keep fluids down (vomiting) or you have severe stomach pain.
  • You have a history of eating disorders, are underweight, or are dealing with serious illness.

For healthy adults doing planned 24‑hour fasts, it’s common to:

  • Start after dinner one day and break the fast before dinner the next day.
  • Break earlier if you feel unwell; the goal is health, not suffering.

Multi‑day fasting should be supervised by a clinician, especially because of the risk of electrolyte shifts and “refeeding” problems when you start eating again.

2. Practical “it’s time to break” checkpoints

Use these as a quick internal checklist: Break now if:

  • You feel lightheaded when standing, or close to fainting.
  • You’re having heart palpitations or chest discomfort.
  • You have intense, uncontrollable hunger that leads to binge‑type thoughts.
  • You have a history of disordered eating and the fast is making food thoughts obsessive.

Consider breaking soon if:

  • You’ve reached your planned fasting hours and are clearly hungry.
  • You’re about to do intense exercise, drive long distances, or need sharp concentration.
  • You’re feeling irritable, “wired but tired,” or sleep is getting worse.

It’s usually okay to continue (for a planned interval) if:

  • You feel generally clear, hydrated, and stable.
  • Your hunger comes in waves but is manageable with water, electrolytes, or non‑caloric drinks (as your plan allows).

3. How to break your fast gently (so you don’t feel awful)

Whenever you decide it is time to break your fast, doing it gently is just as important as the timing:

Good first‑meal ideas:

  • Small portion of easily digestible protein and carbs (e.g., yogurt with berries, eggs with cooked veggies, a small soup).
  • Light vegetable or bone broth, then a moderate meal 30–60 minutes later.

Helpful habits:

  • Start with a small portion, wait 10–20 minutes, then decide if you need more.
  • Chew slowly and avoid “reward binges” with heavy, greasy, or super‑sweet foods right away.
  • A short walk after eating can help smooth your blood sugar response.

Foods to go easy on at first:

  • Large, high‑sugar meals.
  • Very fatty, fried, or spicy foods.
  • Huge portions of red meat or very fibrous raw vegetables immediately after a long fast.

4. Quick answers to common “when do I break it?” situations

  • If you’re just doing 16:8 to lose weight: Break when your daily window opens, and sooner if you’re dizzy or unwell.
  • If you have diabetes, heart disease, are on meds, or are pregnant: Break your fast at the first sign of feeling “off,” and do not fast without clearance from your doctor.
  • If you’re training hard (gym, sports): Many people break their fast before or right after a hard workout so they can fuel and recover, rather than pushing the fast at the cost of performance or safety.

If you tell me:

  • What kind of fast you’re doing (intermittent, religious, multi‑day),
  • Your health conditions,
  • And how you feel right now,

I can give you a more tailored “break now vs keep going” suggestion.