Can I continue intermittent fasting if I’m pregnant and not hungry in the morning?

Mild appetite changes are common, but skipping meals regularly during pregnancy is discouraged.

What if I feel better eating fewer meals per day?

Some pregnant people feel better with 2–3 larger meals instead of frequent snacking, which is fine. But OMAD’s 23-hour fast is too extreme for most.

Could fasting harm my baby’s development?

Possibly. While many babies are born healthy to fasting mothers, there’s emerging evidence that fasting during pregnancy could affect fetal organ development or increase stress hormone exposure.

Is OMAD Safe During Pregnancy? Risks of One Meal a Day While Pregnant

There’s a reason you’re hungrier, more fatigued, or even nauseous when you skip meals during pregnancy. Your body is supporting you, feeding a placenta, growing organs, and preparing for labour. And that means timing, quantity, and quality of nourishment all matter more than ever. For some, OMAD might have worked pre-pregnancy for weight loss or metabolic health. But in pregnancy, restrictive eating patterns carry risks that go far beyond missing a meal or two.

What Is OMAD and Why Do People Try It?

OMAD stands for One Meal a Day. It’s the most extreme form of intermittent fasting (IF), typically involving a 23:1 fast-to-eating window, where you eat all your daily calories within one hour and fast for the remaining 23. Proponents claim benefits like fat loss, improved insulin sensitivity, and mental clarity.

But pregnancy isn’t a time for metabolic experiments. What serves a non-pregnant body might strain a pregnant one.

What Happens to Your Body When You Fast in Pregnancy?

Pregnancy already shifts your metabolism. You become more insulin resistant, enter starvation ketosis faster, and burn through nutrients more quickly to sustain your baby.

When you fast for extended periods:

Your blood sugar drops more quickly than usual.
Your body produces ketones for energy, which can cross the placenta.
Your cortisol levels rise, increasing physiological stress.
You may not absorb nutrients efficiently, especially calcium, iron, and protein, if consumed in one large meal.

These changes can impact both maternal well-being and fetal development, especially if prolonged fasting occurs regularly.

What Does the Research Say About OMAD During Pregnancy?

There’s limited research on OMAD, but indirect evidence from scientific studies provides a lot of insight. A 2018 meta-analysis of over 31,000 pregnancies found that pregnant women who fasted during Ramadan (abstaining from food and water from dawn to sunset) did not have significantly higher rates of low birth weight or preterm birth compared to those who didn’t fast.

However, most of these fasts lasted only 12–16 hours, not 23 hours like OMAD. And women were encouraged to break their fast if unwell. In these studies, the lack of significant harm doesn’t mean fasting is safe; it only means no immediate danger was observed in a subset of women under specific religious fasting conditions.

A study in pregnant rats mimicking daily intermittent fasting found that while pups had normal birth weights, they experienced smaller brain and kidney sizes, and male offspring had reduced growth into adolescence. These findings point to a deeper concern: even if your baby grows normally, fasting could still interfere with organ development in ways that don’t show up until much later.

Some observational studies suggest reduced gestational diabetes risk, but that’s not the full story. However, managing blood sugar through balanced meals and physical activity is a far safer route during pregnancy.

OMAD vs. Your Baby’s Needs: What's at Stake?

If you're only eating once a day, it's nearly impossible to meet daily pregnancy requirements for:

Protein (75–100g/day)
Calcium (1000mg/day)
Iron (27mg/day)
Folic acid, omega-3s, and other critical micronutrients

Beyond intake, there’s the issue of absorption. Your body can only process so much calcium or protein at one time, meaning what you don’t absorb in that single meal may go to waste. Eating small, frequent, nutrient-dense meals is a biological necessity during pregnancy.

Is OMAD Ever Safe in Pregnancy?

Most major health authorities, including:

The American College of Obstetricians and Gynecologists (ACOG)
The NHS
The Mayo Clinic
The Cleveland Clinic

…explicitly or implicitly advise against intermittent fasting during pregnancy. The consensus is clear: Pregnancy is not the time to restrict food intake or eating windows.

Even fasting-friendly doctors and diet advocates, such as those who promote keto or IF outside pregnancy, advise pausing these practices while expecting.

Common Risks of OMAD During Pregnancy

Maternal fatigue and dizziness from low blood sugar
Reduced fetal growth due to nutrient gaps
Increased ketone levels, which may affect fetal brain development
Stress hormone surges that can impact pregnancy hormones like progesterone
Nausea or vomiting worsened by an empty stomach
Higher risk of nutritional deficiencies, especially if vomiting or reflux is present

Why Some Women Consider It Anyway

For women who practised OMAD before pregnancy, continuing the habit might feel like maintaining control, especially in the face of rapid body changes or weight gain fears.

But it’s important to separate control from restriction. There are safer ways to manage weight, appetite, and energy during pregnancy.

Instead of OMAD, consider:

Eating 2–3 balanced meals + small snacks
Avoiding refined sugars and fried foods
Moving regularly, as per your trimester and doctor’s advice
Speaking with a dietitian to plan nutrient-dense meals

FAQs on OMAD While Pregnant: Is One Meal a Day Safe or Risky During Pregnancy?

Can I continue intermittent fasting if I’m pregnant and not hungry in the morning?
Mild appetite changes are common, but skipping meals regularly during pregnancy is discouraged.
What if I feel better eating fewer meals per day?
Some pregnant people feel better with 2–3 larger meals instead of frequent snacking, which is fine. But OMAD’s 23-hour fast is too extreme for most.
Could fasting harm my baby’s development?
Possibly. While many babies are born healthy to fasting mothers, there’s emerging evidence that fasting during pregnancy could affect fetal organ development or increase stress hormone exposure.