Obesity and Pregnancy

Nutritional Care for Obesity and Pregnancy

Obesity during pregnancy raises many risks for both mother and child. However, many of these risks can be lessened with proper nutritional care. Learn more about how to help your nutrition client who is dealing with obesity and pregnancy.

As a dietitian, you may have experience with pregnant women and providing dietary recommendations based on their medical results, genetics, and lifestyle habits. But what if your client is pregnant and has a BMI that indicates obesity? This scenario can be more difficult to manage, but with proper nutritional care, both mother and child can have positive health outcomes.

Before diving into how you (as a dietitian) can provide individualized care, let’s discuss some potential health complications associated with obesity and pregnancy, as well as weight gain and supplement recommendations.

Potential health complications

Obesity is one of the most common health problems for women of childbearing age and poses risks for both mom and baby [1]. If the mother becomes overweight or obese during gestation, this can lead to many complications, such as risk of miscarriage and stillbirthgestational diabetespreeclampsiacardiac dysfunctionsleep apneaneed for c-sections, and risk of c-section complications [2]. Risks for the baby include birth defects, fetal macrosomia, impaired growth, childhood asthma, and childhood obesity [2].

Another repercussion of obesity during pregnancy is changes to the placenta, as it increases the risk of higher placental weight, vascular dysfunction, inflammation, and changes in placental transporters and mitochondrial activity [5].

Additionally, studies have shown that the placentas of obese women have an increase in insulin resistance and fat mass of the fetus at birth [1].

Weight gain and pregnancy

The U.S. Institute of Medicine (IOM) recommends weight gain of 11 to 20 pounds (5 to 9 kg) during pregnancy for obese women and 15 to 25 pounds (7 to 11 kg) for overweight women. While the recommended amount of weight gain (or weight loss) for obese pregnant women is still controversial, there have been some revisions for recommended weight gain in the three classes of obesity [4]:

  • Class 1 (BMI of 30-34.9): weight gain of 5.5 to 15 pounds (2.5 to 7 kg);
  • Class 2 (BMI of 35-39.9): weight gain less than or equal to 10 pounds (4.5 kg);
  • Class 3 (BMI equal to or greater than 40): it has been hypothesized that weight maintenance can be beneficial, but further studies need to be conducted to prove this true [4].

Research shows that women who don’t gain enough weight during pregnancy have an increased risk for giving birth to babies that are small for gestational age, while excessive gestational weight gain can increase the risk of developing metabolic syndrome [1, 3]. There is also evidence showing that lower-than-recommended gestational weight gain or weight loss has reductions for gestational age births, macrosomia, and c-section delivery [4].

Supplementation, obesity, and pregnancy

Proper supplementation is vital during any pregnancy, but it is especially important when working with women who are overweight or obese. While many vitamins and minerals are essential for pregnancy, here are three nutrients that you should pay attention to:

  • Folate: Obese women are twice as likely to birth a child with neural tube defects due to impaired body distribution of folate and a reduced placental transporter activity of folate [4]. Although there is no set guideline for folate intake for obese women, it’s recommended to begin folic acid supplements at least three months before they plan to conceive [4].
  • Vitamin B12: Research has found that obese women have a higher risk of being deficient in vitamin B12, which has been associated with a 2.5-3 times increased risk of neural tube defects. These findings suggest that obese women should begin supplementing with B12 before conception [4].
  • Vitamin D: When a woman’s BMI increases from 22 to 34, studies show that she is twice as likely to be deficient in vitamin D [4]. Vitamin D deficiency increases the risk of c-section and pre-eclampsia, so it is recommended that vitamin D should be supplemented throughout the entire pregnancy [4].

How can nutrition professionals help?

With all the known health outcomes of maternal obesity, it is important for you to provide your clients with good nutritional care to support the health of both mom and baby. You can accomplish this with the following suggestions:

  • Focus on low-glycemic food sources. Gestational diabetes is a risk for women with obesity, so it’s recommended to suggest nutrient-dense, low-glycemic food sources. A few examples are non-starchy vegetables, Greek yogurt, nuts, seeds, legumes, and berries [6];
  • Level out blood sugar spikes. Many pregnant women face intense cravings, such as carbohydrate-rich foods; these can spike blood sugar levels and increase the risk of insulin resistance and gestational diabetes. To avoid this, you can show your client how to eat carbohydrates with other fat and protein sources to feel fuller longer and help satisfy those intense cravings [6];
  • Have a balanced plate. Balance should be the name of the game when it comes to mealtime. For visual learners, half the plate should aim to be non-starchy vegetables, a quarter protein and fat, and the last quarter carbohydrates [6]. This is a good tool to use if a woman is struggling with excessive gestational weight gain, or for those who want to have a better visual of their food;
Meal plate
  • Practice mindful eating. Mindful eating can be beneficial to use with clients and instill healthy eating habits. This practice helps you become more in tune with fullness signals, feel more at ease with food, and be more comfortable in your body. To learn more about how to establish mindful eating habits with your clients, check out this article;
  • Encourage healthful snacking. Help your client avoid blood sugar spikes by encouraging her to eat small meals and snacks throughout the day. This is especially good for obese women who are at risk of gestational diabetes and insulin resistance. By eating throughout the day, it will help curb hunger levels, stabilize blood sugar levels, and prevent overeating [6]
  • Monitor caloric and carbohydrate intake. It is recommended that caloric and carbohydrate intake should not come below 1,600 kcal/day and 175 g/day, respectively [4]. However, this approach is determined on an individual basis and should be monitored closely.


Obesity during pregnancy can pose great risks for both mother and child, but there are many outcomes that can be improved through nutritional support. Educating your client on the increased risks and long-term health conditions is an important first step in nutrition education.

Additionally, you can measure appropriate weight gain throughout the client’s pregnancy by encouraging her to limit refined carbohydrates and include more low-glycemic foods to manage gestational diabetes and insulin resistance. You can also address any possible nutrient deficiencies (such as folate, vitamin B12, or vitamin D) and supplement as necessary to avoid complications and have a healthy birth.

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1. Catalano, P. M., & Shankar, K. (2017). Obesity and pregnancy: Mechanisms of short term and long term adverse consequences for mother and child. BMJ.

2. Mayo Foundation for Medical Education and Research. (2020, March 21). Pregnancy and obesity: Know the risks. Mayo Clinic.

3. Riley, L., Wertz, M., & McDowell, I. (2018). Obesity in Pregnancy: Risks and Management. America Family Physician, 97(9), 559–561.

4. Parrettini, S., Caroli, A., & Torlone, E. (2020). Nutrition and metabolic adaptations in physiological and complicated pregnancy: Focus on obesity and gestational diabetes. Frontiers in Endocrinology, 11.

5. Gaillard, R. (2015). Maternal obesity during pregnancy and cardiovascular development and disease in the offspring. European Journal of Epidemiology, 30(11), 1141–1152.

6. Nichols, L. (2018). Real food for pregnancy: The science and wisdom of optimal prenatal nutrition. Lily Nichols.