There is controversy over whether or not breastfeeding Muslim mothers should fast. For some authors they should be exempt in any situation (Khalife 2015, Mubeen 2012, Shaikh 2006, Agnew 1997), according to others, they are only excused if there is reason to believe that fasting can cause them or their babies harm (Rashid 2007, Shaikh 2006). In any case, fasting is postponed to a later date (Shaikh 2006, Agnew 1997). Most breastfeeding Muslim mothers fast during Ramadan (Khalife 2015, Kridli 2011), irrespective of the country they live in or their level of education (Jessri 2013, Mubeen 2012, Rashid 2007, Agnew 1997, Prentice 1983). There are few studies that have researched possible changes in breast milk and the safety and impact of breastfeeding due to Ramadan fasting (Bajaj 2012, Kridli 2011). In extreme heat conditions (Gambia) significant changes in milk composition (increase of sodium and osmolarity and decrease of lactose) have been found during fasting hours (Prentice 1984). A decrease in micronutrients such as zinc and magnesium has been found (Rakicioğlu 2006). During fasting hours, breastfeeding mothers compared to non-breastfeeding women have a slightly higher degree of dehydration (4.9% vs 3.8%) but in any case it is mild (Prentice 1984) and they do not undergo clinically significant metabolic alterations (Rakicioğlu 2006, Agnew 1997, Prentice 1984). One in five women noted decreased milk production during Ramadan fasting and an increase in milk supplements was observed in infants less than six months old (Bajaj 2012, Ertem 2001). Since changes in the macronutrient composition of breast milk are not of major clinical significance, the growth of infants is not affected (Rakicioğlu 2006, Agnew 1997).Nor do the levels of prolactin change in the mother or other hormones involved or not in the reproduction process (Cağlayan 2014, Prentice 1984, Prentice 1983). Breastfeeding mothers gain on average 1 kg following Ramadan without significant changes in body mass index (Rakicioğlu 2006). It is prudent for breastfeeding mothers who choose to fast to drink plenty of fluids, and eat nutritious food between dinner and dawn to compensate for daytime losses, avoid excessive daytime activity, and know the signs of risk that would justify - on religious grounds - breaking the fast, such as extreme fatigue, dizziness, nausea or vomiting (Khalife 2015), whilst monitoring their milk production (Bajaj 2012).Some authors, doctors and pediatricians, advise breastfeeding mothers against fasting (Rakicioğlu 2006) especially in the case of exclusively breastfeeding infants under 6 months (Bajaj 2012).(For more information see Paricio, APILAM Blog 2017).