Pregnancy is an experience unlike any other. Along with the excitement and joy over a new baby on the way can come anxiety for a mother wanting to do all the right things for their child. One of the most common stressors for pregnant women is understanding the natural and inevitable weight gain that comes with having a baby. How much is too much? Can you really “eat for two”? And what’s the appropriate amount of calories to consume per trimester? Our guide breaks down the ins and outs of maintaining a healthy weight throughout your pregnancy.
Gaining weight is an essential and normal part of pregnancy and serves to support the growth and development of your unborn baby. When a mother keeps weight gain at a healthy range during pregnancy, it can reduce the risk of problematic issues during gestation and delivery. Putting on too much weight during pregnancy can trigger health problems and even complicate childbirth, not to mention making postpartum weight loss more difficult.
Unintentional, rapid weight gain is a symptom of one of the most serious issues affecting pregnant women, preeclampsia.1 Gaining a lot of weight during pregnancy also puts mothers at risk for developing gestational diabetes.2 This condition can result in a large baby, making childbirth more difficult or necessitating a Cesarean section (C-section). However, mothers that are unable to gain sufficient weight may have a baby with low birth weight or experience premature childbirth.12
So how is an appropriate weight gain for pregnancy calculated? First, you need to determine your prepregnancy (initial) Body Mass Index (BMI).3 Your BMI is a measure of body fat based on your height and weight. From there, the Institute of Medicine has provided guidelines for weight gain throughout pregnancy based on your initial BMI.4 It’s important to remember that these guidelines are just recommendations and cannot account for every woman’s individual situation; for this reason, the weight gain suggestions below are given in ranges.
|Total weight gain (lbs)
|Weight gain per week (in lbs, 2nd and 3rd trimesters)
|Less than 18.5
|30.0 and above
It’s also helpful to take a look at a pregnant mother’s caloric intake per trimester. Luckily, there’s no real need to gain much weight during the first trimester (just 1-4 pounds total), so don’t worry if morning sickness has made it difficult to keep the pounds on.8 For women at a healthy weight when becoming pregnant, the following guidelines from the CDC break down your suggested caloric needs per stage of pregnancy:5
These additional calories will ideally come from nutrient-dense foods like protein and whole grains. Just half of a sandwich and a glass of milk can potentially provide you with the extra calories needed in the second trimester. Those with a higher BMI can slightly reduce the number of additional calories suggested; they might be able to meet their calorie goals by adding a serving of cheese and fruit to their daily menu, for example.8
It’s worth noting that even if you closely follow all the guidelines, the reality is that your weight gain during pregnancy might not necessarily follow the book. Some weeks you may gain more than others, and sometimes you may not add on any weight at all. Be sure to keep open communication with your physician and ob-gyn about any concerns you have with maintaining a healthy weight during your pregnancy.
It comes as no surprise that twin pregnancies require a greater weight gain. While there are no published recommendations for pregnancies of triplets (or more), the general guidelines for moms of twins are as follows:5 6
|Total weight gain (lbs)
|Less than 18.5
|30.0 and above
The human body goes through incredible changes throughout pregnancy. Even your blood volume changes, increasing by 45% as mothers provide an ideal environment for fetal growth.7 If you are curious about where all those new pounds are going, here’s a breakdown based on a typical pregnancy:8
Generally speaking, mealtime during pregnancy doesn’t have to be complicated to be healthy — most pregnant women don’t need a special diet beyond eating well-balanced meals. Here are some simple recommendations:
However, pregnant women who have a higher BMI or gestational diabetes may be advised to make diet changes such as reducing their highly refined carbohydrate consumption or increasing their fiber intake.13 And for those with an underweight BMI or who are having trouble gaining the necessary weight, here are a few suggestions:14
When it comes to food safety, your doctor or ob-gyn may mention to you that there are certain foods that a pregnant woman should avoid. In the case that they are contaminated, these foods carry certain risks to your unborn child and their undeveloped immune system. Some foodborne illnesses are very serious and can affect a baby even if the mother does not have symptoms. The FDA offers a thorough guide to this information, and the U.S. Department of Health & Human Services has a webpage dedicated to pregnancy and food safety, but here’s a quick list of foods you should try to avoid during pregnancy:9 15
There are a handful of nutrients that are crucial for fetal health. Be sure to talk to your doctor about what daily prenatal supplements they recommend. You can also consume some of these important vitamins and nutrients through your diet. Here’s a breakdown of the key essentials and where to find them in common foods.18
This nutrient helps reduce the risk of neural tube defects (NTD) in your baby. These defects affecting a baby’s spinal cord and brain occur in the first 3-4 weeks after conception. The CDC recommends that women who can become pregnant consume 0.4mg (400mcg) of folic acid per day. This increases to 600mcg per day when pregnant.25 And, for women who have had a previous pregnancy affected by an NTD, the recommendation is that the dose be increased to 4mg (4,000mcg) each day from the month before becoming pregnant through the first trimester.19 In addition to supplementation, you can find folate in foods like peanuts, beans, fortified cereals, and dark green leafy vegetables.20
Iodine is essential for your baby’s brain development. Luckily, in the United States, most of our salt is iodized, so adding the usual salt to your food is usually enough for a non-pregnant person. However, a pregnant woman needs to consume 0.22mg (220mcg) of iodine daily,26 so the American Thyroid Association and the American Academy of Pediatrics both recommend pregnant or breastfeeding women take a daily supplement containing 0.15mg (150mcg) of iodine.21 28 29 This mineral can also be found in food sources like seafood, seaweed, dairy products, and eggs.22
A fundamental part of a healthy pregnancy is the incorporation of regular exercise. Working out can help you manage weight gain, but it also greatly benefits your overall health, including your psychological well-being. Research has also demonstrated that physical activity can reduce fatigue and is associated with a shorter labor and fewer childbirth complications.10
And while pregnancy isn’t the time to start an intense, new workout regimen, with your doctor’s approval, 150 minutes (2.5 hours) of moderate aerobic exercise a week is ideal for an expecting mom, according to the American College of Obstetricians and Gynecologists. If this sounds like a lot, breaking your exercise into small increments can make this goal easier to attain. Below are some examples of pregnancy-safe exercises.11
The most simple of exercises, walking, can be a great boost for maternal health. With a low impact on your joints, walking can be a great way to get outside (and maybe absorb some vitamin D) while engaging in moderate aerobic conditioning.
Swimming is known for being easy on joints while giving a full body workout. The water supports your weight and reduces swelling, giving pregnant women an excellent opportunity for relief from aches and pains while conditioning their bodies.
Both yoga and Pilates can be wonderful tools for improving circulation and building strength. While you should avoid taking a “hot” yoga class due to the risk of overheating, prenatal classes that are designed with pregnant women and their unique needs in mind are often available. Try to avoid poses or positions that require you to lie flat on your back for an extended period of time, though, as your uterus can compress a large vein that returns blood to your heart (the inferior vena cava). This is also why sleeping on your back during pregnancy is not recommended.23
There are also some exercises that should be avoided during pregnancy, particularly more intense exercises and ones that can put you at risk of injury or falls such as the following:11
Additionally, it’s important to drink plenty of water to stay hydrated during exercise, especially while pregnant. If you haven’t exercised in a while, be sure to start slow and work your way up to meet your weekly goals. You know you’re pushing yourself too hard when you can’t carry on a conversation while working out.
Some expecting mothers have special circumstances that can make exercise unsafe — this can include having placenta previa, cervical cerclage, preeclampsia, or a history of preterm labor.11 Always ensure you have clearance from your doctor or ob-gyn before working out during pregnancy. Additionally, if you experience any of the following warning symptoms while exercising, discontinue your workout and contact your healthcare provider:11
For some, accepting your new body during and after pregnancy can be a hard pill to swallow, while others have an easier time embracing the new curves that come along with carrying a baby. Either way, it’s easy to feel pressure to look a certain way. Culturally, we are inundated with societal expectations to “bounce back” immediately after giving birth.
Our bodies can do amazing things, and the ability to grow and give life to another human is pretty incredible. The dietary choices you make and the pounds you gain during pregnancy serve as nutrition and fuel for your baby. While it may feel unwelcome to suddenly have a new shape, try to take comfort in what you are providing to your new little one as you undergo changes in each trimester.
The Office on Women's Health offers some suggestions on how to love and accept your pregnant body:24
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Mayo Clinic. (2022). Preeclampsia. Mayo Foundation for Medical Education and Research (MFMER).
Centers for Disease Control and Prevention. (n.d.). Gestational Diabetes. CDC.
National Heart, Lung, and Blood Institute. (n.d.). BMI Calculator. U.S. Department of Health and Human Services, National Institute of Health, National Heart, Lung, and Blood Institute.
Institute of Medicine and National Research Council. (2009). Weight Gain During Pregnancy: Reexamining the Guidelines. The National Academies Press.
Centers for Disease Control and Prevention (n.d.). Weight Gain During Pregnancy. CDC.
Luke, B., Hediger, M.L., Nugent, C., Newman, RB., Mauldin, JG., Witter, FR., & O’Sullivan, MJ. (2003). Body Mass Index--Specific Weight Gains Associated with Optimal Birth Weights in Twin Pregnancies. The Journal of Reproductive Medicine, 48(4), 217-224.
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Leite, C. F., do Nascimento, S. L., Helmo, F. R., Dos Reis Monteiro, M. L., Dos Reis, M. A., & Corrêa, R. R. (2017). An overview of maternal and fetal short and long-term impact of physical activity during pregnancy. Archives of Gynecology and Obstetrics, 295(2), 273–283.
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University of Rochester. (n.d.). Low Birth Weight. University of Rochester Medical Center.
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U.S. Department of Health & Human Services. (2020). People at Risk: Pregnant Women. FoodSafety.gov.
Food and Drug Administration. (2021). Advice about Eating Fish: For Those Who Might Become or Are Pregnant or Breastfeeding and Children Ages 1 – 11 Years. FDA.
Food and Drug Administration. (2022). Selecting and Serving Produce Safely - Sprouts: What You Should Know. FDA.
The American College of Obstetricians and Gynecologists. (2023). Nutrition During Pregnancy. ACOG.
Centers for Disease Control and Prevention. (2022). Folic Acid. CDC.
National Institutes of Health. (2022). Folate - Fact Sheet for Health Professionals. NIH.
Centers for Disease Control and Prevention. (2023). Iodine. CDC.
National Institutes of Health. (2022). Iodine - Fact Sheet for Health Professionals. NIH.
University of Rochester. (n.d.). Sleeping Positions During Pregnancy. University of Rochester Medical Center.
U.S. Department of Health and Human Services. (2021). Pregnancy and body image. Office on Women’s Health.
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Food and Nutrition Board, National Academies, Oria M., Harrison M., & Stallings V. (2019). Dietary Reference Intakes (DRIs): Recommended Dietary Allowances and Adequate Intakes, Elements. National Academies Press (US).
National Institutes of Health. (2023). Iron - Fact Sheet for Health Professionals. NIH.
American Thyroid Association. (2013). American Thyroid Association (ATA) Issues Statement On The Potential Risks Of Excess Iodine Ingestion And Exposure. ATA.
Council on Environmental Health, Rogan, W. J., Paulson, J. A., Baum, C., Brock-Utne, A. C., Brumberg, H. L., Campbell, C. C., Lanphear, B. P., Lowry, J. A., Osterhoudt, K. C., Sandel, M. T., Spanier, A., & Trasande, L. (2014). Iodine deficiency, pollutant chemicals, and the thyroid: new information on an old problem. Pediatrics, 133(6), 1163–1166.
National Institutes of Health. (2022). Choline - Fact Sheet for Health Professionals. NIH.