Maintaining a Healthy Weight During Pregnancy

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.

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

• First trimester (first 12 weeks): no extra calories needed
• Second trimester (weeks 13-26): additional 340 daily calories
• Third trimester (after 26 weeks): additional 450 daily calories

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.

Twin pregnancies

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

Pregnancy weight distribution

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

• Baby: 7-8 pounds
• Breasts: 1-3 pounds
• Uterus: 2 pounds
• Placenta: 1.5 pounds
• Amniotic fluid: 2 pounds
• Blood volume: 3-4 pounds
• Fluid volume: 2-3 pounds
• Fat stores: 6-8 pounds

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:

• Fresh fruits and vegetables make great snacks
• Select bread made with whole grains
• Eat smaller, bland meals to help with nausea
• Watch out for snacks and drinks high in added sugar
• Add in healthy fats from olive oil, avocado, and nuts

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

• Eat smaller meals more regularly
• Try to eat more high-calorie, nutrient-dense foods (whole grains, starchy vegetables, dried fruits, protein, whole milk dairy products)
• Add additional healthy fat sources to your diet (peanut butter, cooked eggs, dark chocolate)
• Take bigger portions when you do feel hungry
• Consider adding protein or meal-replacement shakes for extra calories

Foods to avoid during pregnancy

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

• Raw seafood
• Fish high in mercury16
• Unpasteurized juice and cider
• Raw milk and soft cheeses
• Refrigerated meat spreads and pâté
• Undercooked eggs, meat, and poultry
• Raw sprouts (onion, alfalfa, clover, radish, and mung bean sprouts)17
• Unbaked dough
• Unheated deli meats and hot dogs

What about dietary supplements?

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

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

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

• Contact sports
• Skiing
• Surfing
• Off-road biking
• Horseback riding
• Gymnastics
• Scuba diving

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

• Chest pain
• Feeling dizzy or lightheaded
• Painful uterine contractions
• Difficulty breathing
• Vaginal bleeding
• Dizziness
• Headache
• Fluid leaking from the vagina
• Calf pain or swelling
• Muscle weakness

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

• Express how you feel to your partner, family, friends, or even a therapist
• If it’s safe for you, exercise or prenatal yoga can help clear your mind
• Get a massage to relieve stress and anxiety (if approved by your healthcare provider)
• Learn as much as you can about pregnancy and why these physical changes happen