When New Moms Gain Weight, is it the Pregnancy or the Parenthood?

  • 5 Minutes Read
  • Feb 21, 2017

It’s a widespread belief: pregnancy leads to permanent weight gain for women. But is it true? A new study suggests not.

When New Moms Gain Weight, is it the Pregnancy or the Parenthood?

"Oh your figure will be ruined!"

That was the cheerful comment I got many years ago when I told an acquaintance I was pregnant. Gee, thanks so much, looking forward to that. In fact, I'm guessing plenty of other women have gotten that message one way or another. The popular belief is that pregnancy itself causes permanent weight gain. How many stories have you heard from women who complain they just can’t lose the baby weight. Meanwhile the mainstream media adds insult to injury by gushing over the handful of skinny celebrities who shrink back to their pre-pregnancy weight a week after giving birth. It’s like there’s a conspiracy to make normal women feel bad about their bodies.

Having struggled with the same problem, I was encouraged to read about a new study that asked the question "Is post-pregnancy weight gain caused by the pregnancy, or something else?" The results aren't all that surprising: it’s not the pregnancy, it’s the parenting.

Obviously women gain weight during pregnancy. A good rule of thumb is 25 lbs if you start pregnancy at a normal weight, and somewhat less is you start pregnancy while obese. Your obstetrician will have more specific recommendations for your particular situation. Some women gain more than recommended, although a lot of that weight may be fluid build up. One thing you should not do is restrict food intake to limit weight gain. Another bad idea: gorging on food because you’re “eating for two”. You aren’t; you’re eating for 1.1. Paying attention to hunger cues and appetite is the best approach. Hunger may vary widely during pregnancy. At first you may not eat more than normal, especially if you have morning sickness. You might find you have more appetite during the middle of pregnancy.

After the baby is born, weight drops off as your body recovers, but this can take some time. Women who nurse their babies may think breastfeeding speeds up weight loss, but that’s not necessarily true. Again this is not an excuse to overeat because you’re “eating for two”, as a newborn may need 400-500 calories/day.

So what about the new mom’s weight? Weight loss after pregnancy depends on a lot of things:

The study in question used data from more than 28,000 women who had gone through at least 2 pregnancies during the 8 year study period. The researchers estimated what women who had not been pregnant would have weighed after that time period. The average yearly gain was just shy of 2 lbs. They compared that to the average weight gain for the study moms. They found that for 1-2 years after giving birth, they averaged just under 2 lbs of weight gain/year. But after the third year, they gained more than expected, almost 3 lbs/year on average. By 5 years after giving birth, their average weight gain was 5 lbs more than expected.

Why? The study authors concluded that it’s parenthood, not pregnancy that makes mothers gain more weight. Think about how life changes with motherhood:

Keep in mind, this study was based on averages, meaning some women gained more weight from parenthood effects, while others may have consciously taken steps to avoid weight gain.


The good news is that pregnancy weight gain is not inevitable. The other good news is that the parenthood effects on mom’s weight can be altered. You can take charge.
The bad news: if you want to take charge and avoid creeping weight gain, you’ll need to add that to your list of new mom responsibilities. And that can be exhausting. Parenting itself can leave women feeling exhausted. Adding your own needs to the mix might be tricky.


Weight gain isn’t inevitable. You can take some steps to avoid it. Key word “some”. Don’t feel like you have to do everything all at once. Here are a few ideas to get started:

1. Exercise. As your child grows into a toddler, you might be getting more sleep, but you probably feel like you have less personal time to exercise, especially if you work outside the home. And when you do have free time, exercise might not be the first thing on your mind. But physical activity is critical to weight management, and also to your sense of wellbeing. You don’t need to spend hours at the gym. Walking is fine, and if you can push your child in a stroller so much the better. Baby/toddler backpacks are another option to help get you moving. You and your partner can swap parenting time so both can get exercise. If you work, you might exercise during lunchtime. There are plenty of ways to organize this. The hardest part is sticking to the schedule, or getting back on schedule when family demands interfere.

2. Cleaning your child’s plate is never a good idea. First it indicates you dished up too much food. Second it’s food you don’t need, assuming you have your own adult meal to eat. Scrape it into the trash and re-think portion sizes.

3. Buying kid food that you end up eating is another bad idea. First, why do kids need tempting (junky) treats? Snacks and desserts can be fruit or yogurt or cheese or vegetable sticks. There is no daily requirement for cookies or candy, especially if you end up eating them.

4. The sedentary life: Reducing the amount of time you spend in sedentary activities (watching TV, reading to your child, driving them to activities, sitting with them while playing games, etc) may be one of the hardest changes to make. Our sedentary lifestyle affects everyone, not just parents, but parents may have fewer options to avoid it. Sometimes you just have to sit with your child. Sitting while reading a book to your child is a lovely way to spend time together. Sitting in front of the TV not so much. So maybe TV time is turned into outdoor play time instead. And if you find yourself driving your little one here, there and everywhere for activities, you might think about prioritizing those and switching to activities closer to home that allow for more physical activity.

5. Eating out of stress or boredom is never a good habit. Unfortunately, parents of young children have plenty of opportunities to feel stressed. If you tended to be an emotional eater before pregnancy, you might return to this counter-productive coping strategy. I wrote about emotional eating for the holidays, and some of the tips apply all year long. For parents, identifying triggers and keeping tempting treats out of the house are two strategies that can help you get a handle on this. Partnering with other moms nearby by can help by offering social support. You can have babysitting coops, playdates, group visits to playgrounds and other outings get your mind off problems and let you all share ideas. Because I guarantee, you aren’t the only one dealing with parenting issues, and you aren’t the only one working to maintain a healthy weight.


Pregnancy does not equal permanent weight gain. The more likely cause is lifestyle changes that come with parenting, and those can be controlled.

Weight Gain->Unwanted Weight Gain
Donna P Feldman MS RDN is author of "Feed Your Vegetarian Teen", writes about food and nutrition at Radio Nutrition and is co-host of the Walk Talk Nutrition podcast series.
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