NUTRITION FOR LACTATING MOTHERS

Maternal diet is important for growth and development of infant. Thus, mothers need to have good nutritional status before, during and after pregnancy. Before pregnancy, mothers should be informed on healthy diet, weight management, use of folic acid supplement and physical activity. Optimal nutritional status before pregnancy will ensure that mothers will have healthy pregnancy and pregnancy outcome. During pregnancy, mothers need to be counseled on healthy diet as it is associated with pregnancy weight gain. Low or high weight gain during pregnancy will have adverse effects on both the mother and infant.

The production of breast milk is referred to as lactogenesis and it occurs in three stages. The first stage is towards the end of last trimester of pregnancy while the second and third stages occur after the birth of infant. Breastmilk is the best food for infants especially in the first six months of life due to its nutrient composition and immune factors. Maternal diet during lactation will not only provide the energy and nutrients required by the mothers but also determine the quantity and quality of breastmilk produced to meet the needs of infant growth and development. Sometimes, breastfeeding mothers may have healthy infants although their diets are not adequate. During lactation, milk production is a priority and it occurs at the expense of the mother’s nutritional status. The body will continue to produce quality milk even though the mother’s nutritional status is poor. If mothers continue to have inadequate diet, the production of breastmilk can further deplete her nutrient stores. And, if they plan to conceive in the future, there is a possibility that the body is not able to meet the higher nutritional needs during pregnancy.

After delivery, mothers should be encouraged to breastfeed their infants and advised to replenish nutrient stores, return to pre-pregnancy weight, prevent problems in subsequent pregnancies and reduce chronic disease risks. To achieve these, mothers should maintain certain healthy behaviors adopted during pregnancy such as not smoking, eating healthy and variety of foods and leading an active lifestyle.

Energy and nutrient requirement during lactation

Energy requirement during lactation, especially in the first sic months after delivery, is highest compared to during pregnancy and non-pregnant state (Figure 1). This requirement is based on the energy loss during milk production and the expected weight loss (0.8 kg/month) during lactation. Studies have shown that although mothers rarely met their energy requirement, many still were not able to lose weight to pre-pregnancy level. How does this happen? The body may balance the low energy intake with low energy expenditure to ensure that mother does not lose weight or has minimal weight loss.

Lactation also increases protein requirement of mothers. In general, if energy intake is inadequate, protein intake is likely to be insufficient. Diets that are plant-based or less in animal foods are also more likely to be insufficient in protein. Although there is no significant increase in the requirement of other nutrients, studies have found that lactating mothers did not have adequate intake of calcium, folic acid, zinc, iron, vitamin A and C. Mothers should not only increase their food intake but also ensure that their food choices are healthy, balance and variety in order to meet their energy and nutrient requirement.

Group

Energy (kcal)

Not pregnant

19 – 29 years

30 – 50 years

 

2000

2180

Pregnancy

1st trimester

2nd trimester

3rd trimester

 

 

2000/2180 (no addition)

2360/2540 (+360)

2470/2650 (+470)

 

Lactation

1st 6 month

2nd 6 month

 

2500/2680 (+500)

2000/2180 (depending on the amount of breastmilk produced)

(Source: NCCFN, 2005)

Nutrition and lifestyle practices during lactation, especially in the postpartum period (six weeks after delivery) may vary among cultures. In western countries, women are encouraged to consume variety of foods from all food groups and have moderate physical activity. These practices will not only help the body to replenish the nutrient stores but also start the weight loss process towards achieving the pre-pregnancy weight.

However, in many cultures, including Malaysia, there many beliefs and taboos related to maternal recovery during postpartum, especially in the 30-60 days after delivery. These practices are based on traditional beliefs that certain foods and physical activity can interfere with the recovery of mothers. Do these traditional practices affect lactation? At present, there is lack of scientific evidence to support the advantages or disadvantages of these practices. However, mothers should know that the nutrient composition of breastmilk depends on maternal nutritional status and the quality of breastmilk is preserved over its quantity when mothers have poor nutritional status.

Lactating mothers should be aware of the followings:

  1. Lactation increases maternal requirement for energy to ensure that nutritional needs of mothers are satisfied and the breastmilk produced is adequate in quantity and quality to support infant growth and development. Mothers should choose foods wisely in order to fulfill both energy and nutrient needs. Energy and nutrient intake will be inadequate if mothers restrict their diets, especially meat, fruits and vegetables, during lactation. Maternal diet should include variety of foods from all food groups – grain and cereals, fruits, vegetables, meat/fish/legume, milk/dairy products. Practise balance, variety and moderation in food intake.

  2. The consumption of fruits and vegetables is commonly restricted during lactation, especially in the postpartum period. Fruits and vegetables are important sources of fiber, vitamins, minerals and important non-nutrient components. Although restricting these foods for one month to 1½ months (postpartum) may not have long-term effect on maternal health, lack of these foods can result in constipation especially if mothers also restrict water consumption. Many mothers believe that they have to avoid certain foods and drinks because these will cause colic in infants. Restricting food intake over a time period can lead to nutrient deficiency. If infants were colicky after intake of a particular food, perhaps mothers would want to avoid the foods at least 72 hours. After that, mothers should try again consuming the food but in small quantity or according to the infant’s tolerance.

  3. Lack of physical activity or exercise and high intake of energy-dense foods during lactation can result in slower or reduced weight loss even though mothers are breastfeeding their infants.  Many studies have shown that energy intake according to recommendation and moderate physical activity can contribute to modest weight loss through increase in metabolic process and fat oxidation in the body. Does exercise affect the quantity and quality of breastmilk? Evidence shows that moderate physical activity does not have adverse effect on production, nutrient composition and immune factors of breastmilk.

  4. Additional energy requirement during lactation (+ 500 kcal) takes into account a weight loss rate of 0.8kg/month. If mothers exclusively breastfeed their infants (in the first six months) and continue to breastfeed thereafter as well as eat healthy foods and exercise, they should be able to return to pre-pregnancy weight in six to 12 months. Overweight and obese mothers may have higher weight gain during pregnancy and slower or reduced weight loss during lactation. Thus, it is important for these mothers to know the recommended pregnancy weight gain, dietary and physical activity guidelines and not to lose weight during pregnancy. During lactation, mothers should maintain the healthy eating and physical activity behaviors adopted during pregnancy. Also, overweight and obese mothers should be advised not to increase their energy intakes (+500 kcal) as this will help them to lose weight during lactation.  

  5. There is no evidence to support that increasing fluid intake will increase milk production and decreasing fluid intake will reduce milk production. As breastfeeding increases fluid requirement, it is important for lactating mothers to drink enough fluid. How much fluid is required during lactation? The amount of liquid needed varies depending on the climate, milk production, body size and other factors. However, a simple way to monitor adequate fluid intake is to keep the urine clear or pale yellow.

  6. Mothers should avoid smoking as nicotine can be transferred to the infants through breastmilk. In addition, avoid alcoholic drinks as alcohol can retard infant growth.

Maternal nutrition during lactation is a part of a life-cycle that includes nutrition of mothers during pregnancy and in non-pregnant state. It is important for mothers to have optimal or adequate nutritional status in these three periods of life-cycle as the impacts are not only on infants but also on future health and nutrition of the women.