Pregnancy & Weight Gain: How to Know If You’re Not Gaining Enough

Many women struggle with gaining too much weight during pregnancy. But what happens when the opposite is true, and you’re not gaining enough weight during pregnancy? Here’s what you need to know about weight gain during pregnancy.

There may be several reasons that you’re not gaining enough weight during pregnancy—it could be due to excessive nausea, loss of appetite, food aversions, or other digestive concerns. If you’re concerned that you’re not gaining enough weigh, don’t worry. I’ve got you covered. Plus, check this out if you’re looking for the ultimate guide to pregnancy nutrition.

In this post you’ll learn:

• How to figure out how much weight you should gain
• Calorie intake during pregnancy (how do I know how much to eat?)
• How to choose calorie and nutrient-dense foods
• Why Smaller more frequent meals might help
• Why you might want to skip the salad
• Why you shouldn’t turn towards junk food for extra calories
• How to combat nausea
• How to notice food aversions

How to know whether you’re gaining the right amount of weight during pregnancy

First of all, it’s important to understand what healthy pregnancy weight gain looks like. A common way to calculate your target weight gain during pregnancy is by using your pre-pregnancy Body Mass Index (BMI).

Now, I really don’t want to get stuck on the numbers here—especially when it comes to your body mass index (BMI)—because what’s defined as “healthy” according to BMI charts can be a little deceiving or unfair. For example, someone who has lots of muscle may have a higher BMI than what’s considered “healthy,” but may be in great shape and very healthy. Or someone who has a “healthy” BMI due to their genetics may have an unvaried diet and never move their body. BMI is just one assessment tool you can use, but it’s imperfect. Don’t get stuck on it! But for those of you who like numbers, here they are:

To calculate your pre-pregnancy BMI, multiply your weight in kilograms by your height in meters squared. Or if you want a shortcut, just google “BMI calculator” and plug your numbers in. The recommended weight gain during pregnancy depends on which category the pre-pregnancy BMI lands in.

Pregnancy Weight Gain

Prepregnancy BMI	Weight category	Weight gain for full-term pregnancy	Weight gain for full-term pregnancy with twins
Below 18.5	Underweight	28 to 40 pounds	No set guidelines
18.5 to 24.9	Normal weight	25 to 35 pounds	37 to 54 pounds
25.0 to 29.9	Overweight	15 to 25 pounds	31 to 50 pounds
30.0 and above	Obese	11 to 20 pounds	25 to 42 pounds

Calorie intake during pregnancy

I’m not keen on overemphasizing calorie goals or ranges because I really want to encourage you to listen to your body when it comes to the amount of food you eat at any given meal or snack. And quite frankly, counting calories sucks and takes the enjoyment out of eating! But here’s what I will tell you:

• During your first trimester, it’s not necessary to eat any more than normal. So just eat like you normally would!
• During the second trimester, it makes sense that you’re hungrier than normal, because your energy and nutrient needs are rising. It’s good to eat a little more: about 300 to 350 extra calories. That’s like an extra snack each day.
• During the third trimester is when your nutrient and energy needs are the highest throughout your pregnancy, and it’s advised to eat an extra 400 to 450 calories per day. That could be an extra snack (Greek yogurt, berries, and granola) or maybe a little more at each meal.

How many extra calories do I need (assuming that you’re starting out at a healthy BMI)?

Stage of pregnancy	Calorie intake
First trimester	No additional calories
Second trimester	Add 300 to 350 calories per day
Third trimester	Add 400 to 450 calories per day

Any additional calories that you take in should come from nutrient-dense foods such as lean protein, vegetables, fruits, and whole grains. Limit foods that are overly processed with a lot of added sugar, salt, or fat to only once in a while. But do give yourself permission to indulge once a day on something that you absolutely love and can’t live without.

I’m having trouble gaining enough

If you’re having trouble gaining enough weight during pregnancy, know that you’re not alone. This is a common concern and something that can be managed with a little bit of extra knowledge and even some help from a registered dietitian if you and/or your doctor are concerned. Lack of weight gain can happen because of many reasons, including:

• excessive nausea
• loss of appetite
• food aversions
• other digestive concerns
• you might be a small or particular eater to begin with, and may need to pay a little bit more attention to what and how much you’re eating.

To help ensure that you are gaining enough weight throughout your pregnancy, and in a healthy way, here are my top 6 tips:

1. Choose calorie-dense (and nutrient-dense) foods

If you have a small appetite, it’s crucial to make every bite count! That means you want to get the most nutrition (protein, vitamins, minerals etc.)in the foods you choose. Even if you get full quickly or have a small appetite, you know you took in some great nutrition. Foods that are high in calories and chock-full of nutrients are:

• Nuts, seeds, and nut butters
• Avocados
• Olive oil as a topping or dressing
• Whole grain pasta, oats, brown rice, and other whole grains
• Legumes like lentils, chickpeas, and beans
• Fatty fish like salmon

If you’re needing some recipe inspiration for nutrient-dense meals and snacks, check out one of my fave cookbooks, Nourish. On top of this, you should be making sure that you’re taking a prenatal multivitamin, vitamin D and perhaps even an Omega-3 supplement too. Here are some nutrients (and foods) that you should be paying extra attention to during pregnancy.

2. Try smaller, more frequent meals

 You may be turned off of larger portion sizes of foods, and eating might feel overwhelming if your plate is too full (which can actually decrease your appetite). Instead, try having five or six smaller more snack-sized, lighter meals that aren’t so overwhelming. For example, instead of having a big spaghetti dinner, have a piece of French toast with greek yogurt and berries. Or make a batch of homemade protein-rich muffins or energy bites that you can snack on throughout the day or on-the-go. These snack-sized meals can still pack a nutritional punch and provide the calories that you need, but might be less overwhelming and more appealing (meaning, you’ll eat more!).

3. Salads are great but may be too low in calories

Wait, what? Did a dietitian just advise you to skip a salad? While vegetables are super-healthy, they are not calorically-dense and high in fiber. A big bowl of lettuce with cucumber can make you feel full quickly, but is too low in calories. That’s not enough to meet your needs! If you really have a low appetite and can eat only a small amount, it’s better to have more calories with every bite. For example, try whole grain toast with peanut butter and banana slices (yes, you CAN and SHOULD eat peanuts when you’re pregnant), or a pasta salad with avocado, nuts, meat and cooked veggies which would have more calories than a light green salad.

Look at the numbers to see what I mean:

• Whole grain toast with 1 tablespoon peanut butter and a banana: 220 calories
• 1½ cups romaine lettuce and cucumbers: 20 calories
• 1½ cups romaine lettuce, cucumbers, and 1 teaspoon dressing: 60 calories

If you ARE craving salad, what can you add to it? Maybe it means adding a tablespoon of dressing to your lettuce, and topping it with nuts, seeds, chickpeas, quinoa, avocado, or any other calorie-dense foods.

4. Energy dense foods are fine in moderation

We know what you’re thinking: “I need to eat more calories! I can have all of the ice cream I’ve ever wanted!” If only it were that easy! Yes, you need more calories. BUT. You also don’t need tons of sugar and fat. You want the calories to come from nutritious foods (see list above). Of course, you can enjoy ice cream mindfully, but please don’t get your day’s worth of calories from pint after pint of creamy goodness.

5. Combat nausea in pregnancy

Morning sickness can sometimes turn into all-day-sickness. Luckily, by the time you enter your second trimester, when weight gain starts to ramp up, nausea usually starts to wind down. If you’re one of the unlucky (approximately half of all pregnant women) who feels pregnancy-related nausea, here are some tricks that may help:

• Keep a snack on your night table. Have a bite before bed and in the morning. Soda crackers are a popular option!
• Avoid getting too hungry – that can lead to nausea. It might be your first instinct to avoid food when you feel nauseous, but that is the opposite of what you should do. Eating every two to three hours will help keep nausea at bay! Keep high calorie snack options (like nuts) with you throughout the day.
• Don’t take your nutrition supplements on an empty stomach–make sure you combine with a meal or snack.
• Try ginger. This age old-remedy is backed by science too. Try making tea with fresh ginger. You can use ginger in cooking and baking. Ginger snaps anyone?
• Stay hydrated, especially if nausea is accompanied by vomiting. Try drinking your fluids before or after meals, as opposed to with your meal. This is my favourite water bottle (that I carry around always!) to help me remember to stay hydrated.

If none of these tips help and you really can’t keep any food down, you may have hyperemesis gravidarum, and should discuss it with your doctor. They can prescribe medication to help.

6. Notice food aversions in pregnancy

There may be certain smells or flavors that turn your stomach when you’re pregnant – and often they are foods you used to love. Common food aversions are to strong flavors, such as garlic, onion, spice and coffee. If you can’t stand the taste or smell of certain foods, simply avoid them. Know that it’s totally normal, it’s common, and it will pass!

Commonly Asked Questions About Pregnancy Weight Gain

If you need some personalized guidance on your nutrition during pregnancy, contact us to book an appointment with our dietitian team (most people have coverage for our services through their health benefits plan).