Of all the myths that surround breastfeeding, one of the most predominant and vocal is the idea that breastfeeding, and breastfeeding alone, will cause those pregnancy pounds to just slip away.
How many calories does Breastfeeding really burn?
While it is true that nursing consumes calories, the concept that it will reduce your body mass back to pre-pregnancy size is just not true, at least not on it’s own. Some women have experienced phenomenal and almost effortless weight loss during their breastfeeding journey’s, but those stories are not complete and do not take every factor into account. What if the mother in question ate less than normal, or took walks? What if she nursed more than normal or had twins? What if she made better food choices? She may not have deliberately been trying to diet, but all these contributions need to be considered when one tries to claim that breastfeeding, and breastfeeding alone, causes you to lose weight.
Calorie burn and Breastfeeding Facts
Let’s look at the facts. Breastfeeding DOES burn calories. By some estimates, that number can range anywhere from 300-650 calories per day, with many breastfeeding experts saying that 500 is the norm.
How did lactation professionals decide that 500 calories was the magic number? Well, each ounce of breastmilk contains roughly 20 calories and the average lactating woman produces between 25-35 ounces of milk in a 24 hour period. Some produce more, some produce less, but this is the average. This equals a calorie production between 500 – 700. These are just the calories you are making, but it costs calories to produce them. This February 17th, 2000 article from The New England Journal of Medicine surmises that production efficiency is 80% of the energy produced, or 0.8.
Let’s say you produce 25 ounces of milk per day for your 3 month infant. The formula would then be as follows:
- (25 oz X 20 kcal) / 0.8 = 625 calories
Yet this number is not the final story, nor the final number. To further complicate the process, one has to account for the increased postpartum basal metabolic rate, which means that your body does more with less. The same study suggested the following:
- 0 – 4 months = 300 calories (average)
- 4 – 6 months = 400 calories (average)
- 6 months onward = 500 calories (average)
So that would transform the above formula into:
- (25 oz X 20 kcal) / 0.8 – 300 = 325 calories
Mathematically speaking, when one considers the large range that production and expenditure falls into, 500 calories seems to be the ‘best guess average’ for calories burned. It is also the reason most professionals offer this seemingly arbitrary number to mothers.
Significant, but not everything
Now, while 500 calories sounds like a massive amount of calories, it will not hold true for every situation or every mother. Some days you may burn more, like during growth spurts, while other days you will burn far fewer calories by the simple fact that they eat less or you pump less (if pumping is a factor). Add in those infamous breastfeeding cravings and you have a calorie burn that can vary wildly from day to day – and one that should not be counted on as your only weight loss tool during your postpartum period.
Breastfeeding and Weight loss
Many, many mother’s wish to lose the baby weight they may have gained over the course of a pregnancy, yet the first 6 weeks should be considered a recovery period, especially for nursing mothers. Your body is changing, adjusting and adapting – as well as establishing a milk supply. Eat a balanced diet to appetite and drink to thirst.
If you wish to increase your weight loss after this period, then studies suggest that a calorie reduction of 500 kcals below maternal metabolic balance point would produce a weight loss of 1 pound per week. Please consult your Doctor before beginning any diet or weight loss routine – every mother is different and needs vary from person to person.
Studies have also shown that mild to moderate exercise can also be incorporated into your healthy lifestyle with no noted affect on breastfeeding – despite the old wives tale that nursing mothers shouldn’t exercise. Time to break out that new stroller!
If you are looking for more information on breastfeeding or are in need of a midnight nursing read, please check out my Recommended Breastfeeding Books!
YES! So thankful to see this post as I do think it’s a false promise to women who are – for the most part – feeling like they have a little padding here and there from being pregnant, that breastfeeding means the weight will just be sucked away. Post-partum women need reassurance that their bodies will take time to heal, and that rapid weightloss of any sort is not healthy! Using breastfeeding in this way is totally wrong in my opinion and feeds the myth that women need to return to their pre-pregnancy selves as quickly as possible.
^^ That, all of that! I remember when I was pregnant with my first and I read that breastfeeding was a ‘magic pill’ to quick weight loss… it felt inspired, but ultimately proved false. Oh, I lost some weight – but I should have been more focused on recovery. Your point on how this notion feeds the idea that we need to return to pre-pregnancy quickly is spot on, I couldn’t have said it better myself! =)
Interesting! Everybody is different! I actually am thin to begin with and breastfeeding makes me a little too thin! It’s crazy that it burns 500 calories.
This is so true. I was definitely hoping that my choice to breastfeed would help in my weight loss journey eventually, but that just wasn’t the case. It’s ok, I wouldn’t not breastfeed because of that fact. Again, every body is different.
That’s a good point – I wouldn’t have NOT breastfed if I had known the full facts either, but it still would have been nice to know.
Great read !!
Thank you – and thank you for stopping by!
This is a very informative post, there are a lot of misinformation on breastfeeding and weight loss. And yes, everybody is different some may lose some weight and some may gain while breastfeeding. I wrote something on the similar topic but in an African point of view. you can have a look here https://www.dailylifetalk.com/breastfeeding-and-child-growth/
I’ll take a look at it!
I lost weight super quick with my first set of children and I always figured it was a combination of things. I wasn’t going out of my way trying to lose the weight but have 4 kids under 5 years of age made me super active. I felt bresadtfeeding played a part in it as well but never thought that was THE main thing.
Very informative post.
As a CLC, I love seeing posts like this that help to clarify statements like “breastfeeding makes the weight fall off”. Thanks for an awesome post!
I’m so glad you stopped by! I’m a CLEC too, where do you practice?
I didn’t loose any kind of weight while breastfeeding lol. Probably because I was eating the 500 calories while i nursed! But honestly, feeding my kiddo was all that I was worried about, not really loosing weight.
I think I ate that many while I nursed too! =)