How many calories per ounce of breastmilk do you burn?

Quick Answer

Breastfeeding burns around 20 calories per ounce of milk produced. The number of calories burned per ounce can vary based on factors like a mother’s metabolism and body composition. On average, exclusively breastfeeding mothers burn around 500 extra calories per day.

How Many Extra Calories Does a Breastfeeding Mother Need?

Breastfeeding requires extra energy and calories to support milk production. The calorie needs for lactation depend on factors like:

  • How much milk is produced
  • Mother’s metabolism
  • Amount of fat stored during pregnancy
  • Physical activity levels

In the first 6 months, exclusively breastfeeding mothers need around 500 extra calories per day above their pre-pregnancy energy needs. After 6 months, an extra 400 calories per day is typically sufficient.

The extra energy allows the body to produce nutrient-rich breastmilk to nourish the infant. Consuming adequate calories also supports the mother’s health and helps prevent excessive weight loss.

Calories Burned Per Ounce of Breastmilk

Research has found that breastfeeding burns around 20 calories for every ounce (30 mL) of milk produced. However, the number of calories burned per ounce of milk can range from 15 to 25 calories.

Factors affecting calories burned per ounce include:

  • Metabolic rate – Women with faster metabolisms tend to burn more calories for milk production.
  • Body composition – Women with more lean muscle mass tend to burn more calories than those with higher body fat percentages.
  • Breastmilk composition – The fat and calorie content of the breastmilk impacts energy needs.
  • Breastfeeding frequency/duration – More frequent nursing sessions and longer duration requires more energy.

For example, a mother who breastfeeds 6 times a day and produces 25 ounces (750 mL) of milk would burn around 500 calories.

25 oz breastmilk x 20 calories/oz = 500 calories burned

This aligns with the average 500 extra calories recommended daily for breastfeeding. However, energy needs can vary significantly.

How Milk Supply Impacts Calorie Burn

The amount of breastmilk produced directly impacts how many calories are burned during breastfeeding. Mothers who produce more milk have higher calorie and nutrient needs.

According to research:

  • Producing 15 to 20 oz (450 to 600 mL) of milk per day requires at least 330 to 400 extra calories.
  • At 35 ounces (1 L) of milk per day, mothers need at least 500 extra calories.
  • Producing 55 ounces (1.6 L) or more daily burns over 800 extra calories.

Milk supply varies between mothers and overtime as the baby grows. Usually supply regulates to align with the infant’s changing demands.

Factors that can affect milk production include:

  • How often baby breastfeeds – More frequent nursing signals more milk production.
  • Use of a breast pump – Pumping after or between feedings helps maintain supply.
  • Hydration and nutrition – Good fluid intake and diet supports milk production.
  • Mother’s health – Illnesses, stress, and lack of sleep can impact supply.

Tracking milk supply along with calorie intake can help ensure a mother is consuming enough to meet her body’s needs for lactation.

How to Determine Calorie Needs While Breastfeeding

Determining optimal calorie intake while breastfeeding requires a bit of trial and error. Steps to determine calorie needs include:

  1. Track milk supply and feeding frequency for a few days.
  2. Aim for 500 extra calories per day in the early months, adjusting up or down as needed.
  3. Weigh yourself once per week and aim to lose 1 to 1.5 pounds per week.
  4. Increase calorie intake if milk supply drops or you lose weight too quickly.
  5. Decrease calories slightly if not losing weight as desired.

Aim to get the extra calories from nutrient-dense sources like:

  • Fruits, vegetables, and whole grains
  • Lean protein
  • Healthy fats
  • Dairy products
  • Nuts, seeds, beans, and lentils

Drink plenty of fluids and take a daily prenatal vitamin. Consult a doctor or registered dietitian if you have concerns about your calorie needs while breastfeeding.

Foods to Support Breastfeeding Calorie Needs

A balanced diet containing plenty of the following foods can help meet calorie and nutrient needs for breastfeeding:

Dairy Products

Milk, cheese, yogurt, and other dairy foods provide protein, carbs, vitamins, and minerals like calcium, phosphorus, and B vitamins. Go for unsweetened low-fat or nonfat items.


Eggs are an efficient high-quality protein source containing healthy fats. Boiled, poached, scrambled or in dishes like omelets and frittatas.

Lean Meats and Poultry

Beef, pork, chicken, and turkey supply protein as well as iron, zinc, and B vitamins. Focus on lean cuts and prepare in healthy ways.

Fish and Seafood

Fatty fish like salmon provide omega-3 fats along with protein, vitamin D, selenium, and iodine. Limit high-mercury varieties.

Whole Grains

Choose whole grains like oats, quinoa, brown rice, and whole wheat for fiber, carbs, protein, B vitamins, iron, and magnesium.

Fruits and Vegetables

Fruits and veggies provide bulk along with antioxidants, fiber, vitamins, minerals, and plant compounds. Get a rainbow of produce daily.

Nuts, Seeds, Beans, and Lentils

Great snacks that offer healthy fats, plant-based protein, fiber, magnesium, potassium, iron, and zinc. Pair with fruit or add to salads.

Healthy Fats

Include sources like olive oil, avocados, nut butters, and salmon for essential fatty acids, vitamin E, and calories. Use in moderation.

Example Breastfeeding Meal Plan

Here is a sample one-day meal plan providing around 500 extra calories for a breastfeeding mother:


  • Oatmeal made with milk and topped with nuts and berries – 350 calories
  • Scrambled egg and vegetable – 200 calories
  • Coffee or tea


  • Greek yogurt with apple slices – 150 calories
  • A handful of mixed nuts – 200 calories


  • Tuna salad sandwich on whole grain bread – 450 calories
  • Carrot sticks with hummus – 70 calories
  • Apple – 95 calories


  • Cottage cheese and fruit – 200 calories


  • Roasted chicken breast – 250 calories
  • Quinoa pilaf – 110 calories
  • Steamed broccoli – 55 calories
  • Glass of milk – 100 calories

Evening Snack

  • Whole grain crackers and peanut butter – 200 calories

This provides around 2,370 calories, with about 500 extra calories above the typical non-lactating daily needs.

Foods and Beverages to Limit While Breastfeeding

While breastfeeding, it’s important to continue eating a healthy diet and limit certain foods, beverages, and contaminants:

  • Caffeine: Limit to 200-300mg daily from coffee, tea, soda, energy drinks, etc. Too much can cause baby to be irritable or overstimulated.
  • Fish with mercury: Avoid high mercury fish like swordfish, shark, tilefish, and king mackerel. Limit albacore tuna to 6 ounces weekly.
  • Alcohol: Avoid or limit to an occasional small drink. Alcohol passes into breastmilk and can affect milk supply.
  • Allergenic foods: If baby has a food allergy, avoid that food to prevent reactions. Common allergens are milk, eggs, wheat, soy, peanuts, tree nuts, and shellfish.

Also be cautious with excess sugar, fried foods, processed meats, raw sprouts, unpasteurized items, and contaminated produce to reduce risk of illness for mom and baby.

Tips for Losing Weight While Breastfeeding

Many mothers want to lose weight after pregnancy while breastfeeding. It’s recommended to wait until at least 2 months postpartum and aim for gradual weight loss by:

  • Eating a balanced diet with 500 extra calories in early months then adjust as needed.
  • Increasing physical activity such as walks, post-natal yoga or other light exercise.
  • Drinking plenty of fluids to stay hydrated.
  • Joining lactation support groups for guidance.
  • Waiting at least 6 months for intensive weight loss programs.
  • Being patient and kind with yourself throughout the journey.

Losing about 1 pound per week through diet and exercise is reasonable for most women after the first 2 months while breastfeeding. Quicker weight loss may impact milk supply. Losing weight gradually and fueling your body well for lactation helps promote success.

Supplementing Calories While Breastfeeding

Some mothers have trouble consuming enough calories to meet the needs of breastfeeding. Reasons may include:

  • Lack of time to eat properly
  • Poor appetite
  • Gastrointestinal issues that reduce nutrient absorption
  • Food restrictions due to allergies or intolerance

If this is the case, try the following strategies:

  • Eat smaller, frequent meals and snacks every 2-3 hours.
  • Keep convenient grab-and-go snacks on hand like trail mix, protein bars, yogurt, cheese sticks.
  • Drink high calorie beverages like fruit smoothies made with Greek yogurt and nut butter.
  • Add healthy fats to dishes and snacks.
  • Supplement with a prenatal vitamin.
  • Discuss calorie supplements with your doctor if needed.

The key is choosing calories from nutrient-dense sources that align with dietary needs and restrictions. Work with a doctor or dietitian for personalized guidance if excessively struggling to meet calorie needs.


Breastfeeding provides nourishment and valuable benefits for baby while promoting maternal health. However, producing breastmilk requires extra calories – around 500 more per day in the first 6 months.

On average, about 20 calories are burned per ounce of milk produced. But this can range from 15-25 calories depending on the mother’s body composition, supply, and other factors.

Consuming a balanced diet with adequate calories and nutrition supports milk production while allowing for gradual post-pregnancy weight loss. Work with your doctor if needing additional guidance to meet calorie needs while breastfeeding your baby.

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