Intermittent fasting (IF) isn't one-size-fits-all.
Just because your friend lost 10 pounds doing 16:8 doesn’t mean it’ll work the same for you.

Your body type, lifestyle, and goals matter more than any universal fasting rule.

In this post, we’ll break down what IF style works best for different body types—and how to use our Intermittent Fasting Planner to find your ideal schedule.

---

🧬 What’s Your Body Type?

While not a hard science, the somatotype framework can offer helpful guidance:

| Body Type | Traits | IF Style That May Work | |-----------|--------|-------------------------| | Ectomorph | Lean, fast metabolism, low body fat | 14:10 or 12:12 (gentler fast) | | Mesomorph | Athletic, builds muscle easily | 16:8 or 18:6 (standard fat-burning) | | Endomorph | Slower metabolism, gains fat easily | 18:6 or 20:4 (more aggressive fast) |

🔍 Not sure what your body type is? Use our planner’s goal-based recommendation engine to skip the guesswork.

---

⚖️ Fasting Should Match Your Goals

Here’s how to align IF with what you actually want:

| Goal | Suggested Window | Notes | |------|------------------|-------| | Lose Fat | 16:8 or 18:6 | Focus on hydration + protein intake | | Maintain Weight | 14:10 | Easier to sustain long term | | Improve Focus | 16:8 | Mental clarity from ketosis during fast | | Hormonal Balance (e.g. PCOS) | 12:12 or cycle-based fasting | Avoid extended fasts without guidance |

💡 Pro Tip: Don’t force an intense fast if it kills your energy or workouts. Start small and build up.

---

🧪 Example: Why 20:4 May Backfire for Some

Let’s say you’re active and already lean.

Trying 20:4 (only eating 4 hours/day) might:

• Tank your gym performance
• Trigger fatigue or dizziness
• Increase stress hormones (cortisol)

IF should feel empowering, not like a punishment.

---

🎯 Build Your Custom Fasting Schedule

Ready to try a fasting window tailored to your routine?
Use our Intermittent Fasting Planner to get a personalized recommendation in 30 seconds—free, no login required.

---

Disclaimer: CalorieGenius calculators and articles are for informational and educational purposes only. They do not constitute medical advice, diagnosis, or treatment. Always consult a licensed healthcare provider before making any major changes to your diet or fasting routine.