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!