Breastfeeding And Losing Your Baby Weight

As a new mum, struggling with little sleep, and getting to know your baby, you are dealing with a whole new mindset influenced by changing hormones.

Your body is new too – stretched, soft and leaking.

The pressure is real to ‘bounce back’ and ‘get your body back.’ The thing is, your body didn’t go anywhere, it is doing an amazing job. You have just grown a human, birthed this tiny being and now you are breastfeeding. You don’t need to add more stress to your load: healing your body and taking care of your mental health are the priority right now.

Your body has changed during pregnancy to accommodate and nourish your growing baby – as well as the weight of your baby, the placenta, your enlarged uterus, and breast development; your ribs and your hips have widened, and you have stored fat deposits around your hips, stomach and thighs as protection for your milk supply in case of food shortages.

Most of this weight will come off without any effort over several months to a year as you breastfeed if you simply listen to your hunger cues, eat accordingly, and include some gentle exercise as your body is ready. Remember though, it took nine months to grow your baby, so it can take six to twelve months (or longer) for you to lose the extra fat stores, and it’s common to hold a few kilos until after your baby has weaned – again as protection for your milk supply.

However, while it’s easy for me to say, “don’t worry about the baby weight,” that doesn’t change your body image concerns. So, I asked real mums to share their questions about breastfeeding and baby weight and I have interviewed two amazing dieticians who specialise in supporting breastfeeding mothers – Robyn Price, registered dietician ‘The Breastfeeding Dietitian’ and Allegra Gast, a registered dietician and IBCLC Lactation Consultant at ‘Aloha Nutrition’. 

Here, Robyn and Allegra answer mother’s questions about ‘losing baby weight’:

How much weight is safe to lose while breastfeeding? Is calorie deficit OK if you have lots to lose vs someone who doesn't have much to lose? 

Robyn cautions, “a calorie deficit in any regard is going to send your body metabolism into "starvation" mode.”

This means, that if you aren’t eating enough calories, your body will try to “preserve” itself by slowing down your metabolism and hold onto the weight to protect your milk supply.

Robyn says, “whether that state is safe for one person does not depend on how much weight you carry (and therefore may want to lose). It depends on all other measures of your health and your baby's health.”

I'd like to know how long post-partum is it OK to make an effort to lose weight without affecting supply through diet? And how many extra calories do breastfeeding mums require? I'm assuming this will change at different times post-partum.

Robyn says, “you'll hear that lactating parents need an extra 500 calories per day to make milk, but this is actually inaccurate. "They" estimated this number based on also using a certain number of calories from fat stores laid down in pregnancy. However, how are we to know when and how the body intends to use those fat stores? That is entirely individual to each person's postpartum journey.

Maybe these calories are not intended for milk production, and they are intended for recovery from pregnancy, labour and delivery. So, I always encourage parents to think of fuelling their recovery and milk-making rather than play the guessing game. Your body and baby let you know when it's time for your body to change.”

Allegra says,“the energy required to produce milk to breastfeed exclusively is about 200-500 calories. The additional amount of calories (200-500 calories) is dependent on the amount of breastfeeding (exclusively or partially breastfeeding/pumping) and mother’s additional fat stores.  If a mother already has fat stores (a higher BMI), then the additional 200-500 calories, may not be needed.

Many mums are able to have an abundant milk production with 1800-2200 calories. It is NOT recommended to go below 1500 calories, as this can affect your supply.”

How to maintain and gain weight for those who struggle to gain, and keep losing weight while breastfeeding?

Robyn says, “SNACKS! Having energy and nutrient dense snacks readily available where you sit/lay down to feed your baby. You eat when baby eats.

If that doesn't work and you feel like a bottomless pit, then it may be time to reach out to your healthcare professional to check out thyroid hormones or other medical reasons for unintended weight loss. It's so easy to blame breastfeeding, but there are many factors about the body that influence weight.”

Allegra shares her tips: “It’s hard when you actually don’t want to lose the weight, but the weight is just coming off. Things to look at are:

  • Your diet – are you eating enough? How can you increase the calories?
  • Overworking yourself – are you forgetting to eat? Are you running around doing too much? Take time for yourself
  • Hyperthyroidism – have you had your thyroid levels checked postpartum? You may have hyperthyroidism that causes your metabolism to increase.

Mum Cravings – why?

No, cravings are not simply about willpower – they can be triggered by stress, poor sleep and nutrient deficiencies as your body will crave foods to make up for nutrients that you need.

 Allegra says, “If you are low in calcium or iodine for instance, you might crave ice cream or dairy products. If we’re not getting enough selenium, we might crave sushi.”

Clues about what your body needs can be a bit more subtle: Robyn says, “if you're craving sugar... do you need to eat more "energy" foods (and pair it with other foods to help that energy be sustained)? Or if you're craving salty foods... do you need more sodium in your diet?”

Eating a well-balanced diet (fibre + protein + fat) and a variety of fruits and vegetables, can help ensure you are meeting your nutrient requirements and a breastfeeding appropriate supplement can also be helpful (Check with a dietician or your health carer).

Stress and weight gain

Dealing with a newborn, and the issues that accompany that, such as breastfeeding struggles through to returning to work, can all raise levels of cortisol (a stress hormone), that increases your appetite.

Allegra explains, “the ultimate goal of cortisol is to provide energy to the body during a “fight or flight” response, and what better way to get energy, than by eating. This increase in cortisol, increases your appetite. When you have chronic stress, this ongoing craving of food for energy, can result in weight gain or difficulty losing the weight.”

If you have postnatal anxiety and/or are feeling stressed, please reach out and seek help and consider activities to reduce your stress.

Sleep and cravings

Allegra explains, “two hormones that are affected by your sleep that also regulate your hunger are leptin and ghrelin: Leptin is responsible for telling your brain when you are full and when it should start burning calories for energy. Ghrelin is the exact opposite of leptin and tells your body when to eat and to stop burning calories as energy.

“After a rough night of your baby waking frequently, ghrelin - the hormone that makes you hungry and tells your body to eat, increases with poor sleep making you hungrier. The opposite hormone - leptin, which tells your body it’s satisfied, and you don’t need to eat more, increases with sleep (which if you don’t sleep well, it decreases)

Since carbs are your body’s preferred source of energy, and you’re low on energy, you’re going to want more carbs."

So, what can you do?
  • Acknowledge that last night was a rough night and be okay that your body is craving carbs
  • Be sure to pair your carbs with PROTEIN (at minimum 20-30+ g especially at breakfast). Protein helps keep you fuller longer and helps with keeping your blood sugar even keel
  • Choose complex carbs (higher fibre) which is slow digesting 
  • Be sure to eat breakfast (especially with that protein), if you skip breakfast after a long night, you’ll most likely find yourself extra tired and irritable plus end up snacking the rest of the day
  • Be gracious to yourself! You’re a wonderful parent and this is a hard season!

What role do breastfeeding hormones such as prolactin play in fat storage?

Robyn explains, “here is the thing with hormones - they each have a role in the body that play off one another in a perfect symphony. The body knows EXACTLY what to do to have the right hormone levels to get the desired effect (whether that's to use fat storage or not and in what circumstances); however, it's when the hormonal symphony is out of tune the desired effect does not happen. The desired effect being = make enough milk for baby to grow and thrive. Whatever your body appears like is going to be different in each person, it matters what the body's function is like.”

Struggling to lose weight until after weaning – is this common?

Robyn says, your body is programmed to make milk, not lose weight. It's society's "bounce back" mentality that is making you feel like something is wrong... when in reality - it's completely normal for your body to remain different while lactating. And it's also completely normal for you to settle into an entirely different body once you wean that is not the same as pre-pregnancy. Our bodies are meant to change with different life stages.

Why do some women gain weight while breastfeeding?

Allegra says, “there may be other reasons why you won’t lose the baby weight, but generally it comes down to diet, exercise, sleep and hormones, as explained earlier.”

Robyn cautions that dieting itself can cause weight gain, “excessive and quick weight loss after birth can trigger your body's metabolism into a mode where the next time it gets food to meet its needs... it's going to store as much of it as possible because it doesn't know if starvation is going to come again and wants to be prepared. This is the same concept of "yo-yo" dieting, where you starve and deprive yourself to lose weight fast and then the minute you start eating normal again, your body gains all the weight back AND MORE. To prevent that, you HAVE to meet your body's nutrient and energy needs.”

I would love to know if there is any data / research about intermittent fasting while breast feeding.

Robyn advises, it is not recommended and can have potential negative effects - again, you're putting your body into starvation mode in cycles. It's constantly in a perpetual cycle of trying to come out of starvation mode rather than setting up a system to support recovery and milk making.

What effects can exercise have on breastfeeding/milk supply?

Allegra says, “many mothers might be hesitant to work out, because they think it will jeopardize their milk supply. However, if you think about the numerous athletes and elite runners that train for hours a day – they are still able to breastfeed. By balancing both exercise and nutrition, you may be able to manage your weight.

Robyn also emphasises the need for balance between exercise and nutrition: “if you don't fuel your exercise with energy (food) and hydration (water+electrolytes), you put yourself at risk of an energy deficit and/or dehydration which both can affect milk supply. Your body is resilient, but chronically doing this over time without meeting your needs is a recipe for low supply. You have to meet your increased needs which will be higher than the person who is lactating but not exercising.

Fuel your body!”

For more information about post and antenatal nutrition, see Robyn and Allegra’s websites

And follow them on Instagram @breastfeeding.dietitian and @aloha.nutrition