While it is possible to lose weight safely while pregnant through daily exercise and smaller portions, it isn’t necessarily a good idea. Most pregnant people need to gain weight, although those with higher BMIs should gain less.

Pregnancy, while exciting, may lead to a weight dilemma if you are already overweight. This is because of the inevitable weight gain associated with pregnancy.

Only your doctor can tell you what approach to weight, nutrition, and exercise is best for you and your baby.

But there are some general ways you can lead a healthy lifestyle during pregnancy to help ensure an optimal weight for yourself and your baby.

Most research on weight during pregnancy suggests that weight maintenance is usually the best approach, especially if you are overweight.

For those who have obesity, weight gain beyond what is expected during pregnancy can increase the chances of complications such as high blood pressure, preeclampsia, preterm labor, and gestational diabetes.

However, weight loss during pregnancy is also associated with a chance of delivering a baby with low birth weight. For this reason, maintaining your weight might be the safest approach.

In one 2017 review, researchers concluded that eating a healthy diet and exercising can reduce weight gain during pregnancy and lower the chances of needing a cesarean delivery.

It is typical to gain weight naturally during your pregnancy, with most of this weight gain happening in the second and third trimesters. Your baby also grows rapidly during the last 2 months of pregnancy.

However, gaining weight beyond the expected amount can negatively affect your health and your baby’s development.

Having obesity while pregnant may contribute to complications such as premature birth, preeclampsia, and blood clots.

Since you will gain some weight during pregnancy, it’s important to know how much is healthy. Aim to follow these pregnancy weight gain guidelines from the Centers for Disease Control and Prevention (CDC) based on your body mass index (BMI) before your pregnancy.

BMIPregnancy weight gain in pounds (lb)
less than 18.5
Normal weight
30.0 or more

For those who have obesity at the start of pregnancy, the CDC offers a guide to help with tracking pregnancy weight gain.

If, at any point during your pregnancy, your weight falls within the shaded area of the graph provided in that guide, you should not be trying to lose weight.

If your weight falls outside this range, you can make a consistent and gradual plan, focusing on healthy lifestyle habits.

Here’s how to do so safely during pregnancy:

1. Cut down on calories

The first thing that can help is to manage your daily calorie intake. Eating more calories than you burn is the most common cause of weight gain. It takes a 3,500-calorie deficit to lose 1 lb. In the span of a week, this equates to cutting out about 500 calories per day.

If you had a suitable weight for your height before pregnancy, you will likely need 2,200–2,900 calories per day during pregnancy, but this will vary by trimester:

  • Trimester 1: no additional calories
  • Trimester 2: an extra 340 calories per day
  • Trimester 3: an extra 450 calories per day than when you were not pregnant

Consuming fewer calories can help you lose weight, but be sure to speak with a healthcare professional before trying this.

You can start by keeping a log of how many calories you usually eat. Then, talk with a registered dietitian about how much you can safely cut and which food plans will help.

Nutritional labels for foods in stores and restaurants can give you an idea of how many calories are in each food.

If you usually consume far more calories than this, consider cutting down gradually. For example, you can consider:

Taking a daily prenatal vitamin is essential to ensure that you’re getting all the nutrients you need. Folate is especially important because it helps decrease the chance of developmental irregularities in your baby.

And even if you’re cutting calories, it’s essential to consume enough to provide energy and nutrients for yourself and your growing baby.

2. Exercise 30 minutes daily

Some people may be afraid to exercise during pregnancy, assuming that it may harm their babies. But this definitely isn’t true. While some exercises, such as situps, can possibly be harmful, exercise overall is extremely beneficial.

It can help you maintain your weight, reduce the chance of developmental issues, and even ease some of the aches and pains you might experience during pregnancy.

The current recommendation is the same as for those who are not pregnant: 30–60 minutes of activity per day, 3–5 days per week. If this is too much for you at first, consider breaking up the 30 minutes into shorter blocks of time throughout the day.

Some of the best forms of exercise to do during pregnancy are:

On the flip side, you should avoid any activities that:

  • rely on balance, such as bike riding or skiing
  • involve high temperatures
  • cause you pain
  • make you dizzy
  • involve lying your back (after 12 weeks of pregnancy)

3. Address weight concerns early

A 2014 study involving 114 pregnant women with obesity found that those who received nutritional advice between weeks 7 and 21 of pregnancy were less likely to gain excess weight in the third trimester. The participants also benefited from weekly support group meetings.

Be sure to speak with your doctor and come up with a plan early on. Your doctor can refer you to a dietitian for more advice and meal planning, if necessary.

In addition, if you are overweight and not yet pregnant, research suggests that losing weight before you become pregnant can lower your chances of developing gestational diabetes.

Why am I losing weight during pregnancy?

There are a few reasons you may be unintentionally losing weight during pregnancy.

In the first trimester, it’s common to experience nausea and morning sickness, which can make it difficult to eat. In addition, if you have an underlying medical condition that isn’t well managed, such as type 1 diabetes, you may experience unintentional weight loss during pregnancy.

Do you lose weight right before labor?

You can lose weight right before labor, but this is usually a small loss of 1–5 lbs.

Why am I losing weight in my third trimester?

You may lose weight in your third trimester if your baby is large, because your amniotic fluid can start to decrease.

For most pregnant people, weight maintenance is safer than any form of significant weight loss.

It can be beneficial to monitor your calorie intake and to exercise during pregnancy. But overdoing it to an extreme could potentially harm your baby.

This is why most doctors don’t recommend weight loss during pregnancy unless you’re significantly overweight. Discuss any questions or concerns you have with your doctor.

Your doctor can help you make the safest decision for yourself and your baby. You can always revisit a weight loss plan after your baby is born.