Dieting While Pregnant: Is It Safe?

Have you thought about dieting while pregnant? Although it's not recommended, there are exceptions and it's safe under medical supervision.
Dieting While Pregnant: Is It Safe?
Silvia Zaragoza

Written and verified by the nutritionist Silvia Zaragoza.

Last update: 27 December, 2022

Approximately 45 percent of pregnant women are overweight, which poses an increased risk of complications. For this reason, you may have considered losing weight. However, dieting during pregnancy isn’t recommended. Do you want to know why? Is it safe for you and your future baby?

Ideally, you should plan your pregnancy and go on a diet beforehand. But this isn’t always possible. In addition, it’s normal to gain weight when you’re expecting. This gain usually varies between ten to 35 pounds. But the important thing is to monitor your weight gain to make sure it’s less. How can you achieve this? By following a good diet, as you’ll see below. It’s a perfect time to take care of yourself!

Good nutrition during pregnancy

Nutritional needs increase throughout these nine months as a result of hormonal and metabolic changes, as they’re what allow your baby to develop well. Therefore, it’s essential to meet them.

A pregnant woman eating granola with yogurt and fruit.

Folic acid, iodine, and iron stand out among the essential nutrients during pregnancy. Others, such as fiber and magnesium, reduce some symptoms. Hydration’s also important, so drink water or prepare a soup or puree. And include fruits such as watermelon, melon, or pineapple.

If you want to stay healthy and avoid excess weight gain, base your diet on vegetables, especially green leafy vegetables. Include legumes, fish, white meat, and eggs. Nuts and seeds are a good complement, and don’t forget virgin olive oil for cooking! Remember to include citrus fruits and peppers in your main meals. Why? They facilitate iron absorption and help reduce your fatigue.

And if you have any doubts, discuss them with a dietitian. They’ll even explain to you which foods aren’t recommended because of the risk of toxicosis. This includes large oily fish and unpasteurized cheeses. Rather, consult these ideal menus for the second trimester.

Dieting while pregnant

Although dieting as such isn’t recommended during pregnancy, there are certain exceptions that allow it, as long as it’s done under medical supervision.

With care and supervision

Since 2009, the Institute of Medicine (IOM) recommends gaining 5-9 kilos in people with obesity. It doesn’t mention anything about weight loss. However, we have evidence of both the benefits and drawbacks of dieting. On the one hand, it reduces the risk of macrosomia (birth weight greater than 4-4.5 kilograms). It also helps prevent cesarean sections.

On the other hand, the child may be born with low birth weight in women with a body mass index greater than 40. This has been observed after ketone bodies are produced in the blood. These lead to ketoacidosis with fetal death. Therefore, the results are controversial and more research is needed. It’s also important to only diet under the supervision of a professional. They’ll customize your regimen to include all the nutrients you need. In addition, they’ll follow up to ensure that your loss is progressive.

Dieting while pregnant: if you have any doubts, consult your dietician-nutritionist or gynecologist

Once you’ve spoken to your doctor, follow their instructions. They’ll evaluate your case and advise you on the appropriate caloric restriction. It’s a matter of you continuing to eat without any deficits and making sure it doesn’t affect your day-to-day life. They’ll even advise you on how to alleviate fluid retention and fatigue.

If you have any doubts, call them or ask for an appointment–they’ll be happy to help you! Avoid making hasty decisions and putting yourself at risk. We recommend you avoiding supposed “miracle diets” because they’re deficient. You should also stay away from the consumption of infusions because of the adverse effects.

Take the opportunity to improve your eating habits instead of dieting while pregnant

A pregnant woman in a kitchen holding two halves of an avocado and smiling.

Finally, remember the following:

“Pregnancy is a time to think about your lifestyle, habits, and diet, and how they’ll affect you as well as your child. It is a time to consider whether you want to adopt healthy habits that will be beneficial for you and your baby going forward. It’s never too late to make the right choices.”

-World Health Organization-

Rather than dieting, it’s better to eat healthier. Start by reducing your intake of sugary products as they contribute to weight gain. Do the same with fried and battered foods. In their place, try to eat lots of green leafy vegetables. Also, try to add as little salt as possible to your meals and replace it with spices. Finally, try to eat a variety of foods and healthy cooking.

In short, the idea’s that you hardly gain any weight. In addition to diet, you can exercise. Of course, always under medical supervision by going to a personal trainer. There will be some movements that you won’t be able to perform and your trainer will teach you how to do them differently.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.



This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.