How many extra calories do breastfeeding women burn ? Having disproved the story that pregnant women must eat as much as two people ( read here for the correct diet ), let’s tackle another much sought and debated topic: that of the caloric needs in breastfeeding women.
There are those who think that the metabolism of breastfeeding women is higher than that of a normal woman: in reality, it is not the basal metabolic rate that changes, so breastfeeding women do not burn more calories for a faster metabolism ( source), although some metabolic parameters improve with breastfeeding (for example, insulin sensitivity), but they burn more calories from daily energy expenditure. Breastfeeding burns more calories.

Indeed, many breastfeeding women feel a greater sense of hunger. 
Clearly, if you eat more, this advantage of greater energy expenditure is canceled out.
Let’s see how to understand how many calories are burned with breastfeeding.
We do this with a simple formula , taken from the book The Math Diet by Sharny and Julius Keizer , known for their specialized weight loss programin mothers who have to lose the weight of pregnancy. Sharny, in fact, had six pregnancies. In the first she declared that she had gained a lot of weight because she was convinced that she could eat what she wanted: then, a healthier and healthier lifestyle than her led her to face subsequent pregnancies without accumulating unwanted pounds.

The formula for knowing how many calories a breastfeeding woman burns (on average, huh) is simple, and is customized based on the number of daily feeds and the average amount of milk produced per feed.
Two things that breastfeeding women know.
To find out the total calories burned, the number (in milliliters) of breast milk produced per feed must be multiplied by the number of feeds in 24 hours by the coefficient 0.7.
Yes, don’t worry, I’ll start by example.
Let’s say a woman knows she produces an average of 120 milliliters of milk per feed, and breastfeeds 7 times a day.
According to this formula:
Calories burned with breastfeeding = 120 x 7 x 0.7 = 588 calories.
Generally experts speak of an average of between 400 and 600 calories per day, so here we are.
Clear: if the milk loses volume and the feedings decrease, the calculation must be redone.
These calories add to our average daily calorie requirement.
For a woman who needs to lose weight, it will be enough to stay in need, or eat little more than her needs, to lose the unwanted weight if the treating doctor deems it appropriate to do so while breastfeeding. I remind you that the doctor’s opinion on nutrition in pregnancy and lactation is essential.