What Is OMAD (One Meal a Day)?
OMAD, or One Meal a Day, is an extreme form of intermittent fasting in which all daily food intake is compressed into a single 1-2 hour eating window, followed by roughly 22-23 hours of fasting.
OMAD is the far end of the intermittent fasting spectrum — well beyond gentler protocols like 16:8. Because the fasting window is so long, it forces the body to deplete glycogen stores and rely heavily on stored fat for energy, while also triggering autophagy, the body's cellular clean-up process. Advocates point to potential benefits like time savings, improved focus, and better blood sugar control, but research also links OMAD to risks including elevated blood pressure and cholesterol, plus high dropout rates over extended periods — which is why most guidance recommends building up gradually through 16:8 and 20:4 fasting first, under medical supervision.