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Intermittent Fasting While Pregnant: What You Need to Know

Losing some weight while you’re pregnant isn’t always the best option.

When you’re pregnant, you need lots of nutrients to feed the baby’s growth and maintain steady energy levels. Changing eating patterns could affect your blood pressure, milk supply, and even the due date. Many people suggest that fasting is less risky once you’ve had the baby.

Anyway, you still might want to lose stubborn body fat, and it’s completely normal when you’re going through physical and mental changes. But is fasting safe for pregnant women, and are there ways to create a more balanced diet?

If you’re curious to know the answers, keep on reading.

In this article, we explain if intermittent fasting is safe while pregnant.

Weight Loss During Pregnancy

Trying restrictive diets during pregnancy may not be healthy and can slow down fetal growth. This may affect women’s health while they’re pregnant, so it’s best to avoid losing weight. The baby needs more calories to grow and have a smooth labor process.

However, there are times when weight loss is recommended. For example, in some cases of obesity, weight loss is advised to protect the baby’s development. If you’re perfectly healthy, you should only stick to a consistent, balanced diet with no restrictions.

Just remember that weight gain during pregnancy is perfectly normal. Most women gain 25-35 pounds and can easily lose that once their body has adjusted after birth. Your baby requires extra calories and nutrients to function properly inside the womb.

Always consult with your doctor before changing diets. A healthcare provider knows what’s safe during pregnancy and the risk factors of losing fat. It’s better to have a regular eating schedule with lots of vitamins, minerals, and electrolytes.

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Intermittent Fasting During Pregnancy – Is It Safe?

You should avoid intermittent fasting throughout your pregnancy journey. Not eating for long periods of time can deprive the baby of essential nutrients. Of course, if you still want to try fasting methods, always talk to your doctor first before losing weight.

Your body goes into a short-term fasting state when you don’t eat. This means it chips away at fat stores, eventually reducing your overall body fat percentage. Now, this is great for losing stubborn weight, but it’s not the best idea for pregnant women.

This is because fasting produces ketones – chemicals that may harm the fetus. It’s usually recommended that you eat 300 to 450 more calories during pregnancy rather than restricting calories and going into a metabolic state of ketosis.

Here are some negative links between fasting and pregnancy:

  • Fasting can have an impact on fetus development
  • The placenta might weigh less
  • Reduced placental system restricts fetal growth
  • Babies could have a low birth weight
  • Mothers usually face maternal stress
  • Not eating can alter the baby’s circadian rhythm
  • Maternal fasting can affect fetal breathing movements

It is not considered safe to fast during pregnancy after reviewing these facts. You should speak to your doctor before trying new diets and weight loss routines. A medical professional can tell you more about how much weight is normal to gain during pregnancy.

Risks of Fasting During Pregnancy

There are certain risks and downsides of intermittent fasting that may not be good for pregnant women. You might feel alarmed to hear about them, but avoiding this fat loss method during pregnancy can keep you and your baby perfectly healthy.

Let’s take a look at the 4 risks of fasting during pregnancy:

Possible poor growth of the fetus

Intermittent fasting can slow down or disrupt the growth of the fetus. Now, this only happens when you don’t eat enough, especially during the early trimesters. The fetus will grow naturally through a balanced diet containing all of the important nutrients.

One good nutrient is protein – the building block for essential amino acids. Consuming lots of protein can support your baby’s growth throughout pregnancy. You can get this from lean meat, whole eggs, chicken, plain Greek yogurt, nuts, and salmon.

Possible nutrient deficiency

Fasting for long periods of time may create nutritional deficiencies. This might not be good for pregnant and breastfeeding women. Restricting your calorie intake can deprive the body of certain nutrients, like protein, dietary fiber, vitamins, and carbohydrates.

A nutrient deficiency can cause growth restriction, decreased fertility, and irregular periods. These possible risks may lead to low-birth-weight infants. Aim to eat nutrient-dense foods and speak to a registered dietitian about healthy meals.

May cause low blood sugar

Long fasting windows could lower your blood sugar levels. Frequent hypoglycemia episodes don’t always harm the baby, but could damage your health during pregnancy. A pregnant woman’s blood sugar should be 90 mg/dL or less before meals.

To raise your blood sugar, eat more food with natural sugars. These could be citrus fruits that support strong glucose production in the body. Magnesium is another great mineral, as it regulates insulin levels before and after eating sugary foods.

May cause change in hormone levels

Any type of intermittent fasting can throw your hormones off balance. It might increase cortisol (the stress hormone), which leads to anxiety, insomnia, and intense hunger pangs. Of course, this isn’t something you want when going through pregnancy.

Stress may actually raise your blood pressure. Preeclampsia is a serious blood pressure condition that develops during pregnancy, but this will only occur if you reinforce strict eating habits and follow religious intermittent fasting methods.

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Is It Safe to Fast While Breastfeeding?

Yes, it can be safe to fast while breastfeeding, but only if you meet your daily calorie intake. Your body produces enough milk to satisfy the baby, even when you’re burning calories during the fast. Just remember to get all of the important nutrients as well.

Some nutrients include protein, calcium, iron, vitamin D, and iodine. These will fuel milk production after you have given birth. You should especially get lots of calcium, as it supports your baby’s bone development, muscle contraction, and nerve functions.

There aren’t many studies to conclude whether fasting is 100% safe while breastfeeding. However, most research suggests that fasting is safe when you meet nutritional recommendations, including calories and regular eating times.

Below, you’ll find more information about fasting and breastfeeding:

Taking this research into consideration, we can conclude that intermittent fasting can be safe for women who are breastfeeding. You should get a normal intake of nutrients, even if you want to lose weight. Eating fewer calories won’t benefit you or your baby’s long-term health.

If you do decide to start intermittent fasting while breastfeeding, consult with your doctor beforehand. They can evaluate your current body weight to determine if fasting is suitable. Some doctors also give you valuable tips on reaching a healthy weight.

Safe Nutrition Alternatives for Pregnancy

There are pregnancy-safe alternatives that benefit a woman’s health. Some of these options might be obvious, but getting the right prenatal nutrition is important. Healthy pregnancies can be achieved by avoiding fat loss methods like extended fasting.

Here are 3 safe nutrition alternatives for pregnancy:

Enjoy nutrient-dense foods

Consuming nutrient-dense foods is the best way to keep blood sugar steady and decrease the risk of cardiovascular disease. For example, empty calories like cakes or chocolate desserts can make many pregnant women feel unwell due to the sugars.

Some good examples of food include dark leafy greens, lean meat, whole grains, avocados, dried fruits, salmon, and unsweetened Greek yogurt. These contain lots of protein and fiber that can promote a healthy pregnancy and improve your baby’s health.

Eat mindfully

You might be thinking – how do I eat mindfully while I’m pregnant?

You can take some small steps in your first, second, or third trimester. One habit to form is creating a shopping list detailing all nutrient-dense foods. This will help you follow a particular diet that doesn’t involve religious fasting or calorie restriction.

Starting with smaller portions may give you the confidence to increase your calorie intake substantially during pregnancy. Some people might feel scared to put on too much weight, but this is completely normal when you’re newly pregnant.

One last tip is to find delicious recipes that get you excited. These might be bone broth recipes that are full of nutrition or sugar-free desserts.

Consult your doctor

Of course, talking to your doctor is very important.

They can tell you the disadvantages and risks of intense fasting. Prenatal nutritionists hear the same questions about intermittent fasting, so it might be worth talking to them as well. Just make sure to seek professional advice before trying a fasting diet.

When Can You Resume Fasting After Childbirth?

The first six weeks after giving birth is called the recovery period. You should rest and let the body calm down after labor during this time. A doctor might tell you not to restrict your eating and calorie intake, as this will deplete your energy levels quickly.

If you want to start practicing intermittent fasting, try to wait at least 2-3 weeks. There’s no rush in losing “baby weight” that appeared during pregnancy. Medical professionals can give you more of an accurate time based on your current normal weight.

Every mother will recover at different intervals. Those who are healing from gestational diabetes might need more time before fasting. Remember that losing fat isn’t a straightforward process and requires lots of energy and motivation to achieve.

And when you feel ready and able to start fasting again, try the DoFasting app. It will give you the motivation and confidence to improve your eating habits, increase blood sugar levels and lose weight. It will also help you choose the type of fasting that is right for you and maintain a nutritious diet.

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So, is fasting safe when you’re pregnant?

You should avoid intermittent fasting while going through pregnancy. There are too many risks that could affect your baby and the labor process. You can always try this fat loss method after childbirth since the body adjusts to burning more calories again.

Remember to always speak to a doctor when planning to lose weight. They can offer more advice about fasting and whether it’s suitable for breastfeeding mothers.


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This is an evidence-based article that includes scientific citations. DoFasting’s professional writers and editors prepared the content, which a team of medical experts verified to be accurate.

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