By: Jasna Cameron | Reviewed and Edited By: Amy Vespa, Nutritionist 10/5/23

Although there is plenty of information circulating on the internet and from other sources about breastfeeding positions, latching, nipple care, pumping, and a multitude of other issues, the information regarding nutrition and weight loss during breastfeeding are relatively scant and unreliable.

Young moms have so much pressure to get back into shape pretty much as soon as their baby arrives. Instagram and Facebook are full of examples of heroes who shed their baby weight within weeks after birth. However, the effects of rapid weight loss can have a negative impact on you and your milk production, and by extension, your baby. Sometimes, however, you may notice that you may be skipping meals out of sheer exhaustion or lack of appetite.

Do I produce less milk if I lose weight while breastfeeding?

When nursing, your body requires extra calories to make breast milk. Organizations such as The American College of Obstetrics and Gynecologists advise adding 500 calories a day to your regular diet to keep the process running smoothly (which would be about 4.5 ounces of cheese, 2 chicken thighs plus ½ cup rice, 1 cup beans and 1 cup rice with tahini sauce). Any significant dip in the calorie intake may reduce your milk supply. Missing one meal is not harmful, but any extended reduction in food intake might impact your milk supply.

If you intend to lose weight, taking a gradual approach is advised. Aim for slow and steady weight loss of about 1 to 1.5 pounds per week. The exact amount of calories you need to consume depends on your weight and activity level. In general, a reduction of around 500 calories a day will be about 1 pound weight loss per week. Losing weight faster is not sustainable and usually results in gaining the weight back, and it can affect milk supply.

Some sources also suggest waiting until your baby is two months old before implementing changes to your dietary routine. This will give your body time to adapt to the physical demands of milk production and ensure that you have an adequate milk supply. Additionally, breastfeeding burns an extra 200 - 500 calories per day, so losing weight without drastically cutting your food intake is possible.

Another consideration with rapid weight loss is that your body releases high levels of toxins that are stored in your fat cells. These toxins can potentially enter your breast milk and harm your baby, although the mechanism of how this occurs is still being researched. However, this should not affect your breast milk unless you go on a crash or fad diet that results in rapid weight loss. Stay away from weight loss products, pills, and diet supplements, as these chemicals may enter your breast milk and affect your baby or reduce your breast milk production.

How to Healthily Lose Weight While Breastfeeding

Eat healthy, nutrient-dense foods. While it is not always possible to create a wholesome, gourmet, sit-down five-star meal every time you need to eat, it is essential to develop healthy eating habits. Choosing foods rich in nutrients and minerals that will boost your milk supply should be your priority, such as vegetables, fruit, whole grains, lean meats, and healthy fats.  These foods will also keep you feeling fuller for longer and reduce cravings.

The purpose of a good healthy diet is not just the transfer of nutrients directly into the milk but to keep you going strong while you take care of your baby. Remember that while you are nursing, your body will prioritize milk production over your well-being and deplete all your resources if you are not eating enough. 

Research, backed by the breastfeeding researcher and anthropologist Katherine A. Dettwyler, Ph.D., shows that even in times of greatest famines and in the world's poorest countries, breastfeeding moms produce ample amounts of good quality milk for their offspring. However, they found that sometimes the mother's health suffers. So, ensure that you are getting enough calories from nutrient-dense, whole foods to keep yourself healthy during the process.

Eat more protein. Lean protein, including fish, poultry and lean meat, helps to repair your body tissues, maintains muscle, and provides energy. It also helps to control your appetite. Proteins also help build your muscle mass, speed up your metabolism, and help you lose weight gradually by stabilizing your appetite and energy. You may want to try a protein shake if you struggle to cook and eat enough protein. 

In general, breastfeeding moms need around 1 gram per kilogram of body weight (convert your weight in pounds to kilograms, and that is about the amount of protein you need.) As an example, a palm sized chicken breast has about 27 grams of protein, an egg has 6 grams, peanut butter has 7 grams per 2 tablespoons, 1 cup of Greek yogurt has 16 grams. 

Perform some low-impact exercises. After birth, you may notice that your body feels slightly different from your pre-pregnancy state. It may not be as easy to exercise as it was before you became pregnant. With the hormone relaxin, our ligaments and tendons stretch to accommodate your growing baby. It takes about six months after birth for your ligaments and tendons to return to their pre-pregnancy state. 

Experts recommend only starting with an exercise regime 6 - 8 weeks after your baby has been born. You may try some light walking with your baby in a stroller, or squats and lunges. As time goes on, you will be able to resume your yoga or pilates regime. If you are struggling with issues such as diastasis recti or pelvic floor prolapse, please consult your doctor for advice on when you can resume exercising.

Drink water. Breast milk is primarily composed of water, so staying hydrated will ensure that you can keep up your breast milk supply. In general, we need to drink about half our weight in ounces of water to stay hydrated (for example, a 150 pound woman needs about 75 ounces of water). It is not known if lactating women need more, however having an 8 ounce glass of water before and after each feeding will likely keep you well hydrated. 

Sometimes we confuse our hunger and thirst cues - when you feel hungry often, perhaps you are actually thirsty. Dehydration can cause headaches, fatigue, constipation, dry mouth, and moodiness, so if you are experiencing any of these symptoms, try drinking more water.