Dieting, trying to stay the same weight or losing weight while pregnant — other than in the early weeks — can deprive your baby of nutrients needed to grow and develop.

Published: April 21, 2022 | Updated: March 13, 2023

Losing weight while pregnant, other than in the early weeks, is not healthy for you or your baby.

Dieting, trying to stay the same weight or losing weight in the second or third trimester of your pregnancy can deprive your baby of nutrients needed to grow and develop. Obesity or being overweight during pregnancy can lead to high blood pressure, preeclampsia and issues with blood clotting, as well as gestational diabetes and other complications.

“The best way to have a healthy pregnancy is to optimize your health prior to pregnancy,

including achieving a healthy weight,” said Kara B. Knapp, M.D., an OB/GYN with Norton Women’s Care. “It generally is not recommended to ‘diet’ or attempt to lose weight during pregnancy, because it could keep the fetus from getting essential nutrients.”

Weight gain recommendations during pregnancy

Source: Centers for Disease Control and Prevention.

Being overweight or obese can make conception more difficult, interfere with ultrasound testing and make it more difficult to monitor the baby’s heart.

Complications of being overweight during pregnancy

Preeclampsia – This condition is becoming more common, increasing 25% over the last two decades. Preeclampsia symptoms usually occur after the 20th week of pregnancy up until your due date and can up until six weeks postpartum.

Preeclampsia can range from an elevation in blood pressure up to maternal seizures called eclampsia.

Gestational diabetes – If the body is not able to make and use all the insulin it needs for pregnancy, glucose cannot leave the blood and provide energy. As glucose builds up, the result is gestational diabetes.

Pregnant patients with gestational diabetes are more likely to develop Type 2 diabetes later in life, and high blood sugar can cause rapid fetus growth and delivery complications.

How to not gain too much weight during pregnancy

• Early in your pregnancy, talk to your obstetrician about how much weight you should gain. If possible, work with your obstetrician before you’re pregnant to determine how best to get your body ready for a baby.
• Stay away from high-calorie snacks and empty calories such as chips and candy. Focus instead on healthier foods, including vegetables.
• Monitor your weight gain and make adjustments to your eating habits throughout your pregnancy.
• Continue to exercise to keep your entire body healthy and strong. Talk to your doctor about safe exercise, especially after the 12th week of pregnancy.