The study focused on maternal food sources and nutrient intakes of selected breastfeeding mothers. The marked inadequacies of protein, and micronutrients puts breastfeeding mothers in a critical state of malnutrition which may have an impact on the young breastfed infant. Many studies have shown the association of maternal diet and the quality of breastmilk. In one study it has been revealed that maternal dietary patterns can affect macronutrient intake as well as breastmilk's fatty acid profiles . Moreover, breastmilk content of some vitamins and minerals such as thiamine, riboflavin, vitamin B6, and vitamin B12 were found to be low in mothers with these nutritional deficiencies .
Inadequate protein intake was reported among 37% of the breastfeeding mothers in this study. Protein inadequacy among breastfeeding mothers is very critical because it has been founded in previous studies that a low protein diet reduces prolactin secretion which can affect milk production . In a similar study , poor maternal nutrition especially protein restriction during lactation directly affects the weight of infants wherein it was found out that breastfeeding mothers with restricted protein in their diets during lactation had infants who weighed less compared to its counterpart. This significantly emphasizes the role of protein in the maternal diet in the early stages of life [17, 18].
In addition, results showed a high incidence of insufficient intake of micronutrients, especially for iron (99%), Folate (96%), and Vitamin B6 (63%). Based on previous studies, current dietary iron intakes of breastfeeding mothers are unable to meet the requirements, and even iron fortification is not sufficient to fill the needs of breastfeeding mothers [19, 20]. Iron deficiency may, in turn, cause long term cognitive and motor impairments to the infant that heavily relies on maternal stores since iron plays a critical role in cellular function, brain growth and development through its supporting role in neuronal and glial energy metabolism . On the other hand, deficiency in vitamin B6 can affect breastfeeding since maternal intake is relative to breast milk concentration [21, 22]. This is long-established by the experts' consultation report of the World Health Organization wherein it states that maternal deficiency in vitamin A and B6 can ultimately affect the nutrient status of infants who mainly rely on breastmilk as their source of nutrition . Vitamin B6 deficiency in infants may cause problems in a nucleic acid synthesis which is directly related to the formulation of brain structure.
thus, brain development may be impaired if deficiency arise . In terms of folate intake, maternal folate stores are mobilized into breast milk to sustain their secretion levels, thus breastfeeding women with low intakes will have severely low levels of nutrients as breastfeeding progresses . Folate deficiency may progress into megaloblastic anemia and is critical also for the next pregnancy because maternal folate deficiency may lead to neural tube defects for the developing fetus [24, 25]. Moreover, a considerable high prevalence of inadequate micronutrient intakes was found for Vitamin B12 (46%), Riboflavin (39%), and Thiamine (22%). These nutrients also have a direct correlation between maternal intakes and infant nutrient status as stated in several studies, wherein infant vitamin B12 status is affected by breast milk concentration of vitamin B12 in breastfed infants aged 0 to 6 months [22, 26, 27]. For thiamine, breast milk concentrations, as well as infant status, are heavily dependent on the mother's intake and nutritional status . Furthermore, a previous report shows that severe thiamine deficiency leads to reduced infant growth . The results of this study are aligned with previous studies and surveys, in which suboptimal energy and nutrient intakes are reported in breastfeeding mothers emphasizing the vulnerability of breastfeeding mothers to energy and nutrient inadequacies despite the increased nutrient requirements during this stage of life [30,31,32,33].
It is therefore of prime importance to install programs uplifting the health and nutritional status of breastfeeding women as they are the source of a better quality of breastmilk. From infancy to early childhood years, breastmilk poses an important source of energy and various nutrients through children 6–23 months of age as it can provide most of the child's energy needs, and one-third of the required energy needs for children between 12 and 24 months .
In our study the mean energy intake (2516.7 ± 63.2 kcal/day) of mothers which was 28.6% higher than the estimated EER (1957 kcal/day) might increase the possibility of being overweight/obese. National Nutrition Survey results from 2011 to 2015 have highlighted that the prevalence of Chronic Energy Deficiency and underweight among lactating mothers slightly increased from 11.9% to 12.5%, while overweight barely changed from 17.7% prevalence to 17.5%. This highlights a double burden of malnutrition among breastfeeding mothers encompassing the lack of energy and micronutrients of their diets. According to Fikawati et al. (2014), sufficient nutrient and caloric intake are needed to suffice milk production, recovery after childbirth, maintenance of breastmilk quantity, and quality in its premise to combat maternal malnutrition . However, knowledge dissemination or nutrition education must be intensified so as not to overdo the intake of high caloric foods and improving the variety and nutrient density of the diet, while limiting excessive caloric intake are key interventions. It should be noted that excessive fat intake was also observed in this group of mothers. Uncorrected food patterns may result in cardio-metabolic disorders like diabetes, hypertension, and other vascular diseases. The 2018 National Survey results showed that prevalence of diabetes was 4.2% and hypertension was 18.0% among adults 20 years and over were among the recorded pregnancy complications experienced by this age-group. Moreover, elevated Blood Pressure and impaired and elevated fasting blood sugar affected 2.97% of pregnant women and 5.32% of breastfeeding mothers as reported in the 2013 NNS. The results from the past surveys emphasize the high risk for heart disease and diabetes among pregnant and lactating women, and therefore dietary interventions that can provide solutions to these problems should be considered. While recommendations are increased to meet the demands of lactation, it is equally important not to exceed the recommendations beyond their values in order to prevent accumulation of excessive fat and cause excessive weight gain that is difficult to reverse beyond the period of exclusive breastfeeding.
In terms of commonly consumed foods, rice is the first source of energy and the top source of many key nutrients. The results are consistent with the survey results from the 2018 Expanded National Nutrition Survey wherein it was found out that the top food source for total energy intake among lactating mothers comes from rice (58.1%) . This may be due to rice being a staple in the Philippines. However, besides fish and vegetables, the mothers’ diet lacks other nutrient-dense foods. The study found that overall, fruits (35.37%) and vegetables (18.6–32.9%) were one of the least consumed food groups by breastfeeding mothers (n = 70) and contributed little nutrient intake. This is in conjunction with the study of Shah et al. (2010) which showed low fruit and vegetable consumption, an area of concern identified by HEI-2005, specifically among low-income, early postpartum women . In comparison to existing dietary food guidelines in the Philippines such as the Pinggang Pinoy, which is a Filipino food plate model to convey the right food group proportions per meal basis to meet energy and nutritional demands among lactating women, the results from the study are far from the idle recommendations . In a per meal basis, the recommendation to consume cooked vegetables is around 1- ½ cups for lactating women. However, the results stipulated that there is low consumption of vegetables. Mean fiber intake was only 11 g/day, which is lower than the recommended intake (RNI: 20–25 g) which is detrimental to digestive and cardiovascular health among breastfeeding mothers. Furthermore, fruits and vegetables not only provide good sources of fiber for digestive health but they are also low in energy density but nutritionally dense with vitamins and minerals such as Vitamin C, D, Calcium, and Potassium . In addition, other nutrient-rich foods such as egg and egg dishes (40.0%) and pork (35.7%) were not that commonly consumed either. Poor consumption of egg/egg dishes and pork which are iron-rich foods can be a factor for the high prevalence of iron deficiency (99%) among breastfeeding mothers (n = 70) . Protein recommendations for breastfeeding mothers in the Pinggang Pinoy equates to about 1–2 pieces of medium variety of dish or 2 pieces of medium chicken leg and equivalents per meal ideally to support protein and nutrient needs in this life stage .
Sugar-sweetened beverages (SSB) were among the top sources of nutrients such as vitamin C, calcium, iron, zinc, thiamine, riboflavin, and vitamin A in the diets of breastfeeding mothers. Sugar-sweetened beverages are affordable in the Philippines and are one of the most commonly consumed foods. Thus, these are often used as shuttles for fortification in foods [40,41,42]. This makes sugar-sweetened beverages a source of micronutrients in this population, although overconsumption may increase the risk of obesity as these are rich in high fructose corn syrup that disables insulin secretion and do not enhance leptin production contributing to high energy intake and weight gain . To date, the consumption of SSB is controlled because of the Sin Tax Law.
Strengths: For each participant in the study, 12 food records were collected and analyzed providing a very detailed and strong foundation to assess the nutrient intake. These were collected by trained interviewers, and validated with the subject face to face ensuring no loss of information. In addition, strict quality control was employed to deal with implausible data and removing all outliers. This study is only one of the very few studies reporting the detailed food and nutrient intake very extensively among lactating Filipino women.
Limitations: Added sugar was not evaluated in this study since the data currently not available in the Philippine Food Composition Table (FCT) database. This study also recognizes that the data available only features the intakes of breastfeeding mothers until 90 days which is less than the recommended period of 6 months for exclusive breastfeeding. Furthermore, the nutrient status and human milk compositions were not reported in the study which would have allowed a better understanding of the impact of inadequacies on maternal nutrient deficiencies based on both blood and milk biomarkers. Future research could also take into account other factors that could affect maternal intakes such as socioeconomic factors, financial capability, food consumption habits, and food availability.