University of São Paulo: Quality of maternal dietary fat can interfere with the birth weight of babies

Maternal diet is directly associated with the baby’s health during pregnancy and scientists are already advancing in understanding the factors that contribute to this relationship. A study carried out by researchers at USP’s Ribeirão Preto Medical School (FMRP) shows that the quality of fat ingested by the mother is associated with the newborn’s weight according to gestational age.

“Being born older for gestational age means that the child may be at greater risk of developing diseases in adulthood and even complications during childbirth. In this sense, the research contributes to the understanding of how the quality of fat in the maternal diet interferes with fetal development”, says Maria Carolina de Lima, first author of the article published by Nutrition in November and doctoral student of the Postgraduate Program in Public Health of FMRP.

The study included 734 pairs of healthy mothers and babies who underwent prenatal care at Basic Health Units in Ribeirão Preto, between 2011 and 2012. “We used two forms in order to record everything that was consumed by respondents in the last 24 hours. Then, we assessed birth weight, sex and duration of pregnancy with data from the Information System on Live Births (Sinasc). Finally, we evaluated the quality of fat in the maternal diet”, he explains.

To understand the quality of the mothers’ fat intake, the researchers worked on the analysis of three types of fat, which can also be called fatty acids: saturated, monounsaturated and polyunsaturated. Saturated ones can be found in foods of animal origin: red and white meat, poultry skin, milk, cheese, butter and sour cream. In addition to plant origins such as coconut, palm oil and babassu.

“Being born older for gestational age means that the child may be at greater risk of developing diseases in adulthood and even complications during childbirth. In this sense, the research contributes to the understanding of how the quality of fat in the maternal diet interferes with fetal development”, says Maria Carolina de Lima.

Monounsaturated ones are found in foods such as avocados, nuts, olive oil and canola oil. Consumption of this type of fat can lower LDL, which is called bad cholesterol, and boost HDL, which is known as good cholesterol. The last type of fat evaluated was polyunsaturated, which can be found in eggs, soy and sunflower oils, sardines, salmon and olive oil.

However, those who think that fats have only a negative impact are wrong. “Fatty acids have a positive impact as long as they are consumed in adequate quantity, quality and proportion. Thus, international guidelines recommend the removal of trans fat, reduction in the consumption of saturated fat and inclusion of an adequate amount of unsaturated fats, which are monounsaturated and polyunsaturated fats”, says Maria Carolina.

Thus, the study observed that the intake of some fatty acids has a protective factor if consumed in a balanced way. “Pregnant women had 48% less chance of having a big-for-gestational-age child with the consumption of polyunsaturated fats in the appropriate amount. The data reinforce the importance of evaluating the quality of the ingested fat and monitoring the nutritionist during pregnancy”, she adds.