12 Reasons Why You’re Not Losing Weight While Breastfeeding

As a new mom, you might wonder, “If I’m nursing, why am I not losing weight while breastfeeding?”

You might not be losing the extra weight from pregnancy while breastfeeding, including stress hormones, activity level, caloric intake, the need to maintain a healthy diet, and even a lack of sleep.

I’ll walk you through the 12 reasons you might be holding on to extra pounds as a nursing mom with a new baby.

Woman stepping on the scale. Why am I not losing weight while breastfeeding?

Hormonal Reasons

1. Cortisol

Cortisol is a hormone in your body. It helps your tissues to react to stress. When you are feeling extra stressed, cortisol comes out of the pituitary gland and helps you react to an event quickly. 

Too much cortisol can lead to weight gain. So, reducing stress is important for postpartum weight loss. 

It is no secret that having a newborn baby is stressful for the mother , so new moms tend to have more cortisol in their bodies than others.

If this is your first pregnancy or you’re in the early weeks postpartum, it’s a good idea to try to reduce the cortisol level in your body by relieving as much stress as possible.

Tips for reducing cortisol:

  • Get enough sleep: Cortisol levels are highest when you have not had enough sleep. This is easier said than done with the sleep deprivation that comes with a newborn, right mama?

    But even a few hours of consecutive sleep can be powerful for new mothers. If you have some help, see if they can give your baby one bottle so that you can get 4-5 hours of consecutive sleep at some point during your day.
  • Reduce stress: Take some time for yourself each day to do something that relaxes you.

    Showering every day was my stress reliever during the first few months postpartum. The best thing I ever did was buy a bouncer for my little one to sleep next to me– while I was showering.
  • Eat healthy foods: Avoid processed foods. Eat plenty of fruits and vegetables.
  • Exercise regularly: Moderate exercise helps to reduce stress and gives you a boost of the feel-good hormone, serotonin.

2. Prolactin

The other hormone that affects postpartum weight loss is prolactin, which stimulates milk production in a woman’s body after childbirth. 

Prolactin also suppresses ovulation and menstruation. Thus, most women experience a delayed return of their period when they are breastfeeding.

Because your body releases prolactin every time you breastfeed or pump, there is no way to reduce prolactin while you are producing milk.

If prolactin is the reason you are holding on to your pregnancy weight, you will likely be able to shed some pounds after you stop breastfeeding.

12 Reasons you're not losing weight while breastfeeing. Mommymakerteacher.com.
12 Reasons You’re Not Losing Weight While Breastfeeding

3. Adiponectin

Adiponectin is a hormone that helps to regulate blood sugar and metabolism. Higher adiponectin is associated with lower body weight and lower risk for diabetes.

Breastfeeding mothers typically have more adiponectin than non-breastfeeding mothers (this is a good thing!).

Here are some ways to increase adiponectin:

  • Eat foods that are high in protein, healthy fats, and fiber.
  • Increase your amount of postpartum exercise.

Reducing your cortisol and increasing your adiponectin might help you lose weight faster while breastfeeding.

Remember, there isn’t anything you can do to reduce prolactin while you are breastfeeding, so some additional weight might come off once you stop breastfeeding

Other Reasons:

4. Breastfeeding Calories

Did you know that breastfeeding burns calories?

Breastfeeding women burn about 500 extra calories per day. This extra calorie burn kickstarts your metabolism (this is why you always feel hungry while breastfeeding!).

For some women, burning these extra calories is enough to lose weight gradually.

I gradually lost weight right after delivery while I was breastfeeding despite eating A LOT.

I never counted calories, but I knew I ate more than 500 extra calories daily. Despite this, my metabolism was hyperdrive for the first few months, and I lost weight without thinking about it.

Does this sound too good to be true?

Well, it was. When I went back to work (I was pumping more and breastfeeding less), I started gaining weight that was impossible to lose.  

The moral of the story? If breastfeeding alone is helping you lose weight, enjoy it! And if it is causing you to retain weight despite eating well and exercising, try not to stress too much (stress: cortisol: bad). 

5. Burning Too Many Calories

Did you know burning extra calories can prevent you from losing weight?

When you burn too many calories, your body compensates by slowing your metabolism and holding on to fat stores.

After all, your body wants to ensure you have enough calories to produce an adequate breast milk supply for your baby.

If you’re aggressively exercising–or just chasing a baby and toddler around ?– you might need to increase your daily calorie intake. 

Skip the personal trainers and fad diets at this stage, and once your doctor has cleared you, stick to a well-balanced diet with moderate exercise (like walking).

6. Having A Calorie Deficit

If you burn 2500 calories a day while breastfeeding but only eat 2000 calories, you have a 500 calorie deficit.

Burning too many calories through breastfeeding and exercise can lead to your body going into “starvation mode.”  

Even if you aren’t physically burning a lot of calories during the day, make sure you know how many calories you should be eating in a day (don’t forget to factor in the calories you burn while breastfeeding), and eat your daily recommended amount to avoid confusing your body into thinking it is starving. 

Use a calorie calculator like this one from the Mayo Clinic.

If done correctly, a calorie deficit can lead to weight loss, but you should consult a dietician or healthcare provider before going on a calorie-restrictive diet… Especially while breastfeeding

7. Eating Too Many Calories

If you’re eating too many calories, you might slow your weight loss efforts or even put on weight while breastfeeding

It’s tricky to find the perfect amount of calories you should consume while breastfeeding… Too many are bad, and too few are bad.  

Try writing down everything you eat during the day (or using a food intake app to make it easier) and counting the total calories. This will give you a better idea of your caloric intake. 

8. You Aren’t Eating Frequently

Eating smaller meals more frequently is the key to a fast metabolism

While you’re breastfeeding, it’s tricky to find time to eat regularly. If you don’t eat for extended periods of time (say 6 or more hours), your metabolism will slow down. 

Eating MORE might seem scary, especially if you are trying to lose weight, but you might be surprised at how your body reacts.

Try eating more frequently, but keep an eye on your portion sizes.  

If you’re finding it difficult to cook and prepare meals while you are breastfeeding, stock up your fridge and pantry with grab-and-go options that are just as easy to grab as a bag of chips: 

  • Granola bars (look for the healthiest option) 
  • Bags of nuts 
  • A few squares of dark chocolate 
  • No sugar-added fruit cups 
  • Veggies and dip 
  • Deli sandwiches (who else craved lunch meat during their ENTIRE pregnancy?!) 
  • Etc. 
Why you're not losing weight while breastfeeding. Mommymakerteacher.com. Postpartum woman standing on the scale.
Why You’re not Losing Weight While Breastfeeding

9. You Aren’t Eating The Right Foods

I get it. 

I’m pretty sure I survived on sleeves of Oreo cookies and heaping bowls of sugary cereal in my first few months postpartum… Unfortunately, these are all empty calories and don’t give your body the nutrition it needs.

Finding enough time to feed yourself healthy, nutritious food is almost impossible when nursing your baby around the clock.

This usually leads to moms eating whatever is easy, convenient, and tastes good… Neglecting some of the most important food groups.

Most of the time, these aren’t the best foods to eat. Even most granola bars and trail mixes are just junk food in disguise.

If you eat 2500 calories a day, but in the form of Ben and Jerry’s ice cream, your body will not get the nutrients it needs and will hold on to those fat cells just like if you were starving.

Make it easy on yourself to eat a few servings of healthy fruits, whole grains, lean protein, and vegetables each day:

  • Have easy-to-eat fruits like bananas and clementines on the counter. 
  • Boil a dozen eggs and keep them in the fridge for quick, healthy snacks. 
  • Buy ready-to-eat options like bagged salads with foods like kale and Brussels sprouts.
  • Swap out your white bread (even your crackers and English muffins) for whole-grain or multi-grain options.

10. You Are Emotionally Eating (For Stress, Sadness, Or Comfort)

During those glorious 2 hour naps, you should be sleeping or making yourself a healthy meal, but the stress of the day has you wanting to unwind with a pint of ice cream or a bag of chips on the couch.

Honestly, I don’t blame you, mama. And you shouldn’t blame yourself either.

Yes, this could be why you aren’t losing the baby weight… 

And if you are 6 or 9 months postpartum and the lack of weight loss is bothering you, maybe it is time to swap out those comfort foods for healthy meals, water, and rest.

But, if you are in the early postpartum phase, try to cut yourself some slack.

If indulging here and there brings you comfort and joy, go for it!

If indulging makes you feel guilty or ashamed, try to find something that will bring you joy, like those steaming hot baths and foot massages you missed during your pregnancy.

11. You Aren’t Exercising Enough 

Breastfeeding is a lonely job.

You spend 8 or more hours of your day with your baby physically attached to you.

Finding time to do anything (like go pee or feed the dog) is almost impossible… Let alone finding time for physical activity.

Once your doctor has cleared you for walking, try to go for a daily walk (even if it’s just 10 minutes). For an extra workout challenge, take your baby in a stroller or carrier.

Multitask during this time if you have to.

Did you know you can nurse your baby on the go with a baby wrap?

You can also get in your daily news by listening to a motherhood podcast, a mindfulness meditation, or a postpartum book you’ve meant to read.

Getting exercise while breastfeeding does not have to be going to the gym, running, or doing any other strenuous activity.

Finding time to get up off the couch (or rocking chair) to get your blood flowing and your muscles working will be helpful to your body.

12. You Are Stressed About Losing Weight

If breastfeeding, you should give yourself a 6-month grace period (at the very least) during which you won’t worry about your weight.

Worrying about your postpartum weight while you are breastfeeding is only going to lead to increased levels of stress (cortisol) and can make matters worse.

Whatsmore, this list should prove to you that all bodies react differently and things that help some moms (like eating less and working out more) hurt others (hello!). 

Weight loss while breastfeeding is a very frustrating thing, and you might try everything on this list only to realize it’s not going to make a difference. 

There are so many factors that I have listed to blame for why you aren’t losing weight while breastfeeding that are out of your control…

So, don’t stress about this too much right now. 

As women, I think we all feel the pressure to “lose the pregnancy weight” and “bounce back,” as soon as we give birth. 

If you choose to breastfeed (especially exclusive breastfeeders), you are keeping your child alive, nourished, and hydrated… All by yourself! 

In the first six months postpartum while breastfeeding, the only things you should focus on are whether you are producing enough milk, whether your baby is gaining weight, and whether you and your baby are healthy and hydrated.

Once you wean (which might not be for a long time if you decide to do extended breastfeeding), you might find the weight comes off gradually on its own or that you can get back to a regular exercise and diet that your body will respond to more predictably.  

You’ve got this mama ?! 

Look 10lb Thinner By Fixing Your Diastasis Recti

Bonus: It’s because you have Diastasis Recti

If the numbers on the scale look good to you, but your pregnant-looking belly tells a different story, you might have diastasis recti.

Diastasis recti is the medical term for ab separation. As many as 1 in 2 women suffer from some degree of diastasis recti related to pregnancy.

This ab separation makes you look like you have a “pooch,” “mommy tummy,” or still look 3 months pregnant.

So, while the scale says you have lost all the baby weight, your favorite little black dress says otherwise.

The good news is that diastasis recti is completely fixable, and you can do it with gentle breathing exercises in just 10 minutes a day.

Jacqui headshot



I am the founder of Mommy Maker Teacher and a mom of two toddlers. With a degree in education, 12+ years of experience as a K-12 teacher and curriculum developer, and courses in childhood psychology and language acquisition, I share research-backed parenting tips and advice. I provide helpful content for moms on all stages of motherhood—from trying to conceive and pregnancy to postpartum, breastfeeding, and parenting.