How Much Weight Gain Is Normal during Pregnancy?

By: Lainey Younkin, M.S., R.D.

Pregnancy is an exciting time, but for many women the thought of gaining weight leads to mixed feelings. How much is too much? Where does all the weight go? Will I hold on to the baby weight forever?

First things first: gaining weight during pregnancy is good. Pregnancy is not the time to diet or restrict calories. A fetus cannot grow and thrive without receiving proper nutrients. Perhaps you have heard that the baby eats what you eat. It's true. You provide your little one with all of the nutrition he or she needs until birth.

Still, this time of your life can cause a lot of questions. Read on to get answers to many things you may have wondered about weight gain during pregnancy, plus get some delicious snack ideas for gaining weight the healthy way.

How Much Weight to Gain during Pregnancy

Weight gain recommendations for pregnancy are based on the mother's body mass index (BMI) at the time of conception. If your BMI is in the healthy weight category at conception (18.5-24.9), the Institute of Medicine recommends gaining 25-35 pounds during pregnancy. If your BMI is under 18.5, you should gain 28-40 pounds. If you are overweight (BMI 25-29.9), you should gain 15-25 pounds during pregnancy, and obese women (BMI 30 or higher), should aim for 11-20 pounds of weight gain during pregnancy.

Total weight gain during the first trimester should be around 2 to 7 pounds if your BMI is less than 30. Obese women (BMI 30 and over) should only gain about 0.5 to 4.5 pounds in the first trimester. After the first trimester, aim to gain about 1 pound per week if you are underweight or a healthy weight when you get pregnant, and about 0.5 pound per week if your BMI is over 25. If you are pregnant with multiples, speak with your doctor to determine your weight gain recommendations.

Where Does All the Pregnancy Weight Go?

Pregnancy

If the baby only weighs 6 to 9 pounds at birth, you might be wondering where all that weight goes.

"The weight gain you experience during pregnancy is fluid (blood, amniotic fluid and interstitial fluid), fat and protein stores, increases in tissue (breasts, uterus, placenta and umbilical cord) and, of course, your baby," says Ingrid Anderson, R.D.N., founder of Results Dietetics.

Here's an average breakdown:

• Baby: 7½ pounds
• Placenta: 1½ pounds
• Breasts: 1-3 pounds
• Uterus: 2 pounds
• Amniotic fluid: 2 pounds
• Increased blood volume: 3-4 pounds
• Increased fluid volume: 2-3 pounds
• Fat and protein stores: 6-8 pounds

What Happens If You Gain Too Much Weight?

About one in five women gains over 40 pounds during pregnancy, according to the IOM. Gaining too much weight during pregnancy is unhealthy for mom and baby.

"Aside from making it so you have to lose more weight after delivery to get back to your prepregnancy weight, gaining too much weight will also make you more prone to getting gestational diabetes, which can cause long-term health complications for you and your baby," Anderson says. "Gaining too much weight can also cause your baby to get too large, which could complicate delivery."

According to the Academy of Nutrition and Dietetics, obesity during pregnancy is also associated with high blood pressure, increased risk of cesarean section and birth defects.

If you fall outside the range of healthy weight gain, don't stress out. But you should talk to your doctor and consider switching up your diet or exercise routine.

Tips for Gaining Weight the Healthy Way During Pregnancy

First Trimester

Recommended weight gain: 1 to 7 pounds

Your body doesn't need any extra calories during the first trimester of pregnancy. You should naturally put on 1 to 7 pounds due to increased fluid and blood volume, growing breasts, and fat and protein stores. Some women may actually lose weight in the first trimester due to morning sickness. Aim to eat a balanced diet of fruits, vegetables, whole grains, lean protein, dairy and healthy omega-3 fatty acids during the first trimester.

Throw out the mantra: I'm eating for two, which could lead to overeating and too much weight gain in the first 12 weeks. Take advantage of when you are feeling good to eat a healthful diet and get some exercise.

Second Trimester

Recommended weight gain: 1 pound per week (0.5 pound per week if BMI >25)

"In the second trimester, the average woman needs about 340 extra calories per day. This is equal to about two average-sized snacks per day at 170 calories per snack. Think of an apple with one tablespoon of peanut butter or six-whole wheat crackers with two tablespoons of hummus," says Molly Cleary, R.D., a dietitian at New York-Presbyterian Hospital.

Third Trimester

Recommended weight gain: 1 pound per week (0.5 pound per week if BMI >25)

During the third trimester, the recommendation is to eat about 450 extra calories per day.

Don't feel like you need to count your calories though. "I'm a strong advocate of intuitive eating and that our bodies will give us clues about what we need, even in the context of pregnancy," says Lindsey Janeiro, R.D.N., C.L.C., a dietitian and owner of Nutrition to Fit.

Instead of focusing on calories, listen to your body and focus on nutrient-dense foods full of fiber, protein and healthy fats like avocados, nut butters, nuts and seeds, lean protein, fruits and vegetables. "Try adding healthy fats to snacks and meals, like pairing peanut butter with an apple, cheese or hummus with crackers, blending a portion of avocado into a smoothie, or drizzling extra-virgin olive oil over pasta," Janeiro says.

Focusing on nutritious sources of calories will help you ensure you're feeding yourself—and your baby—a healthy diet all 40 weeks you're together.

Keep Reading:
What to Eat (and Avoid) When You're Pregnant
1-Day Vegetarian Healthy Pregnancy Meal Plan 2,200 Calories