I was warned off immediately from fasting while breastfeeding even intermittent fasting such as eating during a 6 or 8 hour window (fasting for 18 or16) or a full 24 hours once/twice a week. As for intermittent fasting while breastfeeding, since I wanted to begin IF while nursing, I first considered things like established milk supply and breastfeeding history. I was oddly lucky in that no matter how much I exercised, or how little I ate, I kept a steady oversupply of milk. I also wondered about the fact that there are women who have breastfed just fine during famines. I personally think the whole you must eat an extra 500-800 calories while breastfeeding is slightly over exaggerated. And I think trying to eat that way contributed to my having a hard time losing the baby weight. I probably could have maintained my normal eating of around 2200 calories and still nursed. But of course, this is all based off my personal experience with breastfeeding, I definitely wouldn’t recommend this for a mom who may have trouble with nursing. Source
Here is a link to my first week’s experience in Intermittent Fasting while breastfeeding.
And my personal journey to lose weight postpartum
The benefits of intermittent fasting such as Lean Gains and Eat Stop Eat method are inticing to me. Since I wanted to begin intermittent fasting while breastfeeding, I decided to research what the possible effects would be to my milk and milk production as this is my first concern.
Intermittent Fasting While Breastfeeding: Milk Consistency
It seems like many people suggested my milk would turn to crap or poison if I began a fast that was longer than 16 hours. I decided to look at some studies that studied the makeup of lactose/milk after a fast like this. Here is some info from one study done on Muslim women fasting during Ramadan. Muslim women, while not required to fast, often fast during Ramadan (which is 40 days long I believe). This would be a dinner to dinner type of fast that programs like Eat Stop Eat purports. Here is a clinical study done on the quality of breast milk of fasting moms:
In one such study conducted in the UAE at Muwajihi Primary Health Care Clinic, milk samples were taken from healthy breastfeeding mothers, during and after Ramadan. It was discovered that fasting did not significantly affect the level of “macronutrients”. These are nutrients needed in large quantities for growth and energy – namely proteins, carbohydrates and fat. Fasting did affect the level of “micronutrients” – but these are by definition only needed in small quantities, such as magnesium, zinc and potassium.
Sharjah Baby Friendly Emirate Campaign, remarked, “Breast-milk is incredibly resilient, and can retain its major nutrients even during fasting. It’s crucial to maintain the same breastfeeding pattern during Ramadan, to give the baby a sense of continuity and rhythm. If a mother chooses to fast, it’s vital that she replenish her nutrients with a balanced diet encompassing all the major food groups when she breaks her fast each day, and revert to her normal eating habits immediately after Ramadan.”
Here is a study on fasts LONGER than 24 hours. This study was done on breastfeeding moms with babies of 1-6 months old. They took samples from 2 days before and immediately after the mom did a fast of longer than 24 hours. The changes to the makeup of the milk were as follows:
- Sodium, calcium, and Protein increased
- Phosphorus and Lactose decreased
- Triglycerides (fats) were unchanged
After reading about milk consistency of hindmilk & foremilk like here:
This higher-fat hindmilk mixes with the high-lactose foremilk and baby receives the perfect food, with fat calories for growth and lactose for energy and brain development. (1), (2) However, when milk production is too high, baby may fill up on the foremilk and then have difficulty digesting all the lactose that is not balanced by fat. This is known as foremilk/hindmilk imbalance or oversupply.
So the lesser quality foremilk, is higher in lactose. It would seem that the milk is changing it’s makeup. Rather than increasing the triglycerides which were unchanged, the protein is increased.
Intermediate Fasting While Breastfeeding: What about Milk Supply?
Okay. Another thing that even a lactation consultant told me is that my milk supply might be immediately & permanently effected by fasting (meaning it would go down). I also researched this in another study,
the increased glucose demands of lactation are met by increased GPR as a result of increased glycogenolysis but not GNG (non-carbohydrate) or by increased use of FFA. During feeding, lactating women handle oral carbohydrates normally but have increased insulin sensitivity.
What the heck do all those big strange words mean????
GNG stands for Gluconeogenesis and is usually associated with ketosis (like when you’re on a low-carb diet). This process was actually 50% higher in the fasting lactating women.
Glycogenolysis is the breakdown of glycogen to glucose. The speed of this process is GPR
GPR stands for glucose production rate. Where glycogen/sugar is made more available by being made faster into glucose in the liver.
FFA stands for free fatty acids which basically just means fat.
* the increased insulin sensitivity is interesting to me. This is always a good thing. It’s how you’re body reacts to sugar in the blood and keeps it in balance. It’s always good for this to be increased. After a fast, these moms were left with this good quality.
More from this same study: the primary, but not exclusive, source of milk lactose, is plasma glucose. Lactating (L) women may provide approximately 60 g of their glucose pool to meet their infants’ milk (lactose) demands. Basically, there are four factors or possible adjustments the body can make to the fasted state.
1. The breastfeeding mom has to produce more glucose than a non-breastfeeding mom
2. The breastfeeding mom has to reduce her own body’s use of glucose (ketosis starts sooner)
3. The breastfeeding mom could develop low-blood sugar.
4. Or milk production could go down.
This study found that…
the primary mechanism for maternal adaptation to short-term fasting is decreased maternal glucose use by the early development of ketosis and fatty acidemia, thus maintaining a glucose supply for milk production and a constant milk supply for the infant.
So ketosis begins sooner and milk supply is not affected.