OMAD (One Meal a Day): The Complete Beginner's Guide

OMAD stands for "one meal a day" — exactly what it sounds like. You eat all your daily calories in a single meal, usually within a one-hour window, and fast for the other 23 hours. It's the most extreme common form of intermittent fasting, and it's become popular for its simplicity and fast results. Here's how to do it right.

How OMAD works

OMAD is essentially a 23:1 fasting schedule. By compressing all your eating into one meal, you spend most of the day in a fasted state — where insulin is low and your body relies on stored fat for fuel. It also naturally limits how much you can eat, which usually creates a calorie deficit without any counting.

The benefits

Simplicity — one meal to plan, no snacks, no counting most of the day.
Automatic calorie control — it's hard to overeat an entire day's food in one sitting.
Extended fat burning — 23 hours of fasting maximizes time in the fat-burning state.
Mental clarity — many people report steady energy and focus while fasted.

The risks and downsides

OMAD isn't for everyone. Eating only once a day makes it genuinely hard to get enough protein, vitamins, and minerals. It can cause low energy, irritability, or dizziness, especially at first. It's not recommended for people who are pregnant, have a history of disordered eating, are underweight, or have diabetes or blood-sugar issues without medical supervision.

What to eat during your one meal

Because you only get one shot, your meal has to be big and nutrient-dense. Build it around:

A large protein source — aim for 40–60g+ (steak, chicken, salmon, eggs).
Plenty of vegetables — for fiber, vitamins, and volume.
Healthy fats and some carbs — avocado, olive oil, rice, or potatoes for energy.

Don't use OMAD as an excuse to eat a tiny meal — that leads to muscle loss and nutrient gaps. The goal is one large, complete, satisfying meal.

How to start OMAD safely

Don't jump straight to OMAD. Ease in by first doing 16:8 for a couple of weeks, then 18:6, then 20:4, and finally OMAD. This lets your body adapt and prevents the crash-and-binge cycle. Stay hydrated, use electrolytes if needed, and start OMAD a few days a week rather than every day.

The bottom line

OMAD can be an effective, simple tool for weight loss — but it's demanding and not for everyone. Nail your protein, don't undereat, and ramp up gradually. If it feels miserable, a gentler window like 18:6 will get you similar results with far less strain.

MyDietingApp's fasting timer supports OMAD and every other schedule, with real-time body stage education so you always know what's happening during your fast.