You probably heard the rumor that breastfeeding makes the baby weight melt right off. So, why is the scale stuck? It is incredibly frustrating when you are doing all the work but not seeing the results you expected.
While nursing burns calories, it also triggers biological mechanisms that can make weight loss tricky. I found I had to do more than just feed my baby to shift those pounds; I had to understand my body’s new chemistry.
Our medical team is here to explain why the weight might be sticking around. We will share practical tips to boost your metabolism and support your body so you can feel like yourself again.
Key Takeaways
- Calories vs. Hunger: Breastfeeding burns roughly 500 calories a day, but increased appetite often leads to consuming more than you burn.
- Hormonal Hurdles: High prolactin levels and low estrogen can trigger fat storage and slow down your metabolism.
- Stress Factors: Lack of sleep and high cortisol levels from new-mom stress can prevent your body from letting go of weight.
- Nutrition Matters: Focus on nutrient-dense foods like lean proteins and leafy greens rather than calorie restriction to protect your milk supply.
How Breastfeeding Supports Weight Loss
There is truth to the claims; making milk is hard work. Your body burns between 300 and 500 calories a day to produce breast milk (1). That is roughly the equivalent of a 45-minute jog, all while you sit in a glider.
Additionally, breastfeeding triggers the release of oxytocin. This hormone helps your uterus contract and return to its pre-pregnancy size faster (2). This process, called involution, helps flatten your tummy in the early weeks postpartum.
However, many moms lose the initial fluid weight and baby weight in the first few weeks, only to hit a plateau. If the scale stops moving, biology might be fighting back.
Reasons You Can’t Lose Weight While Breastfeeding
If you feel like you are doing everything right but the zipper still won’t go up, give yourself some grace. Your body is prioritizing milk production over being skinny. Here are the primary culprits.
1. Your Hormones (Prolactin)
Your hormones run the show during postpartum recovery. The main player here is prolactin. This hormone is responsible for milk production, and levels stay elevated while you nurse (3).
Research suggests that high prolactin levels can suppress fat metabolism (4). Essentially, your body holds onto fat stores as an “insurance policy” to ensure you can feed the baby even if food becomes scarce. Prolactin is also a powerful appetite stimulant, causing that intense “breastfeeding hunger.”
2. Your Caloric Intake
You are burning calories, but are you eating them back? The hunger that hits after a nursing session can be fierce. Since you are tired and busy, it is easy to grab quick, processed carbohydrates.
If you burn 500 calories breastfeeding but eat an extra 800 calories in snacks because of the hunger hormones, you will gain weight. It is a simple math equation that is very hard to balance when you are sleep-deprived.
3. Sleep and Stress (Cortisol)
Sleep deprivation is practically a job requirement for new moms, but it wreaks havoc on your waistline. When you are exhausted, your body produces more cortisol (the stress hormone) and ghrelin (the hunger hormone).
High cortisol levels encourage your body to store fat, specifically around the midsection (5). If your adrenal glands are overworked from constant stress and lack of sleep, your metabolism slows down to conserve energy. You aren’t just tired; your body is in survival mode.
4. Thyroid Issues
This is often overlooked. Postpartum thyroiditis affects about 5% to 10% of women in the first year after giving birth (6).
This condition can cause an underactive thyroid (hypothyroidism), which drastically slows down your metabolism and causes weight gain, fatigue, and depression. If you are exhausted and gaining weight despite a healthy diet, ask your doctor to check your thyroid levels.
Tips for Losing Weight When Breastfeeding
You can support your body without starving yourself. The goal is to work with your metabolism, not against it.
Can I Diet While Breastfeeding?
You can diet, but you must be careful. Crash diets or extreme calorie restriction can tank your milk supply and leave you exhausted.
If you decide to actively diet:
- Wait 2 Months: Give your body 6 to 8 weeks to establish a solid milk supply before cutting calories.
- Go Slow: Aim for a weight loss of about 1 to 1.5 pounds per week. Losing weight faster than this releases toxins stored in your fat cells into your bloodstream, which can end up in your milk.
- Minimum Calories: Most experts recommend staying above 1,800 calories per day while nursing (9). If you dip too low, your body will fight to hold onto fat.
FAQs
Does Extended Breastfeeding Cause Weight Gain?
Extended breastfeeding does not inherently cause weight gain. In fact, toddlers often take more milk volume than newborns, potentially increasing calorie burn.
However, as your baby starts solids and nursing sessions decrease, your calorie burn drops. If you do not adjust your food intake to match the lower energy demand, you might see weight creep back on.
Does Pumping Help You Lose Weight?
Yes, pumping burns calories just like nursing does. Your body does not know if the milk is going into a baby or a bottle; it only knows it needs to produce it.
Exclusive pumpers often have a great handle on exactly how much they produce, making it easier to estimate how many extra calories they need to eat to maintain supply.
How Long Does It Take to Lose Weight While Breastfeeding?
There is no set timeline, but “9 months on, 9 months off” is a healthy expectation. Some women drop the weight by 6 months, while others hold onto the last 10 pounds until they wean completely.
Genetics, metabolism, and stress levels play huge roles. Focus on how your clothes fit and how you feel rather than just the number on the scale.
Why Have I Stopped Losing Weight While Breastfeeding?
Hitting a plateau is common around the 3 to 6-month mark. This often happens because your body has adapted to the calorie burn, or your sleep debt has accumulated, spiking cortisol.
To break the plateau, try switching up your exercise routine to build more muscle or tracking your macros to ensure you aren’t accidentally overeating sugar or carbs.
