Does breastfeeding really burn calories and if so how much?
Does breastfeeding really burn calories and if so, how many extra calories can I eat? This is a question often asked by pre and postnatal women when considering the pros and cons of breastfeeding. There are many anecdotal claims online and in the wider health and fitness community that state breastfeeding burns calories to the extent that it can help new mothers to return to their pre-pregnancy weight. These sources even cite specific daily calorific amounts, ranging from anywhere between 300-500 calories per day. But where does this number come from and more importantly, is it accurate? This is what we’ll explore in this article.
Is it 500 Calories?
The additional 500 calories per day value is regularly cited in blogs, magazine articles and even the occasional scientific paper. On this basis, you’d be forgiven for thinking that it is factual and that the value was reached at the end of some strong, authoritative research. But you would be wrong! In actual fact, the 500 extra calories per day is the result of a small study that didn’t even measure calorific expenditure to determine whether a woman burns more calories or not while she is lactating. What it actually measured and subsequently reported was the number of additional calories women who were exclusively breastfeeding their babies consumed in comparison to partially breastfeeding women, and those feeding their babies on a formula. On average the breastfeeding women tended to consume an additional 500 calories more than their formula-feeding counterparts, and so the myth was born! To make matters worse, the data collection in this study was self-reported, which is a notoriously unreliable way of collecting scientific information.
Part of the reason why this myth has been so effective is because on the surface the mechanisms supporting it seems so plausible. If the body is doing more work [lactating] then it must require more energy right? There are two ‘possible’ mechanisms by which lactation ‘could’ help to contribute to a calorie deficit; the first is through its effect on basal metabolic rate (this is the amount of energy burned at rest) and the second is related to dietary-induced thermogenesis (heat production from food intake). However, the evidence is generally unclear as to whether lactation has any direct effect on either of these two mechanisms.
According to Dewey (1997), women who are exclusively breastfeeding require around 670 additional calories per day. This estimate has been reached by considering breast milk volume, milk energy density and the conversion efficiency from dietary energy to breast milk. It also ‘assumes’ that both thermogenesis and basal metabolic rate are increased during lactation. If therefore a postnatal woman wants to lose weight steadily, consuming only 500 additional calories per day will create a net deficit of around 170 calories each day (1190 per week). Simples, as those little meercats from the TV adverts say!
A modest weight loss of around 1lb per week (or 0.5kg) is generally thought to be safe in the postnatal period. However, is this achieved when most postnatal women report gaining weight in the weeks and months after the birth of their baby? Research in this area suggests that modifications to both diet and exercise will have the greatest effect and that low-calorie diets are only likely to result in more cravings, increasing the chance of a relapse. Furthermore, a daily energy intake of 1600 calories or less could actually threaten milk production. However, in the case of twins and triplets, milk production is greater and so this base threshold will need to be increased somewhat. In the battle for postnatal weight loss, slow and steady will always win the race.
Look at what you’re eating
Focusing a little more on dietary factors, how is it possible to create an energy deficit when you are sleep deprived, exhausted, hungry and you constantly have a baby (or two) attached to you? The key here is to think more about what you are eating as opposed to how much. Several studies have revealed that the diet of lactating women is often deficient in grains, vegetables and dairy, which are all food sources that result in satiety and food satisfaction. Ensuring that you eat these foods is likely going to reduce those cravings for high energy and sugary snacks. What’s more worrying however about these deficient food groups is that they are all essential sources of micronutrients, like vitamins D and B12, calcium and iron (Robert-McComb 2014). Reduced milk production is usually attributed to low protein intake. Unsurprisingly however, a balanced diet of wholegrains, fresh vegetables and lean protein is the optimum breastfeeding diet to ensure a high-quality and sustained production of milk. Not only will increasing your intake of protein and fresh vegetables benefit your baby, it will also support your weight loss ambitions by controlling your blood sugar, reducing food cravings, leaving you feeling fuller for longer.
About the Author
Naomi Schon is a Registered Midwife (RM) with over 10 years’ midwifery experience. She is also a fully qualified Personal Trainer, yoga teacher and a Pilates instructor. Naomi is currently the lead clinical consultant for all things related to pregnancy and postpartum exercise at Health and Fitness Education (HFE), focusing primarily on their pre and postnatal courses and personal training courses.
References and Further Reading
Journal of the American Dietetic Association Volume 111 (1) 67–74.
S L Nascimento, J Pudwell, F G Surita, K B Adamo and G N (2014) The effect of physical exercise strategies on weight loss in postpartum women: a systematic review and meta-analysis Smith International Journal of Obesity 38, 626–635.
J. J. Robert-McComb, Á. García González, L. Carraway. (2013) The Active Female Nutritional Guidelines and Energy Needs During Pregnancy and Lactation 517-533.
K. G. Dewey. (1997) Energy and Protein Requirements During Lactation. Annual Review of Nutrition 17 19-36.
*This is a sponsored post in collaboration with HFE