Optimal protein intake during pregnancy for reducing the risk of fetal growth restriction: the Japan Environment and Children’s Study

Abstract

Clinical trials show that protein supplement increases infant size in malnourished populations; however, epidemiological studies in high-income countries have reported mixed results. Although these findings suggest a non-linear relationship between maternal macronutrient intake and fetal growth, this relationship has not been closely examined. We assessed the association between maternal protein intake and fetal growth among 91 637 Japanese women with singletons in a nation-wide cohort study using validated FFQ. The respondents answered the FFQ twice, once during early pregnancy (FFQ1; 16·3 (sd 6·0) weeks), and second during mid-pregnancy (FFQ2, 28·1 (sd 4·1) weeks). Daily energy intake and percentage energy from protein, fats and carbohydrates were 7477 (sd 2577) kJ and 13·5 (sd 2·0), 29·5 (sd 6·5) and 55·3 (sd 7·8) %, respectively, for FFQ1, and 7184 (sd 2506) kJ and 13·6 (sd 2·1), 29·8 (sd 6·6) and 55·3 (sd 7·9) %, respectively, for FFQ2. The average birth weight was 3028 (sd 406) g, and 6350 infants (6·9 %) were small for gestational age (SGA). In both phases of the survey, birth weight was highest and the risk of SGA was lowest when the percentage energy from protein was 12 %, regardless of whether isoenergetic replacement was with fat or carbohydrates. Furthermore, when protein density in the maternal diet was held constant, birth weight was highest when 25 % of energy intake came from fat and 61 % came from carbohydrates during early pregnancy. We found maternal protein intake to have an inverse U-curve relationship with fetal growth. Our results strongly suggest that the effect of protein on birth weight is non-linear, and that a balanced diet fulfilling the minimum requirement for all macronutrients was ideal for avoiding fetal growth restriction.

Maternal mid‐upper arm circumference during pregnancy and linear growth among Cambodian infants during the first months of life

“…As reported earlier, the diet of women of reproductive T A B L E 1 General characteristics of children and pregnant women in the study T A B L E 2 Bivariate analysis infants' (aged 0 to 3.5 months) LAZ and independent variables using imputed data age is mainly based on rice, vegetables, and a little fish (Som et al, 2018). This dietarian pattern does not change during pregnancy (Som et al, 2018) when energy and nutrient intake should increase to allow for optimal growth of the foetus (Morisaki et al, 2018;Williamson, 2006).…”

Macronutrient and Micronutrient Intake during Pregnancy: An Overview of Recent Evidence

“…It should be noted that the latter findings regarding high protein supplements were derived from a single trial from 1980, which comprised 505 poor urban African American women with a history of low birthweight (LBW) infants [23]. A recent observational study of 91,637 Japanese women suggests an inverse U-shaped relationship between protein intake and foetal growth [24]. This may be due to the satiating quality of protein in the control of hunger and appetite, such that at higher levels it could have a self-limiting effect on energy intake.…”

Maternal dietary intake of vitamin A during pregnancy was inversely associated with congenital diaphragmatic hernia: the Japan Environment and Children’s Study

“…The concept and design of the Japan Environment and Children's Study (JECS) have been previously detailed (13) . Briefly, we recruited women as early in pregnancy as possible, in fifteen Regional Centres located throughout Japan, and registered 103 099 pregnancies from 2011 through 2014 (14)(15)(16) . The respective distributions of maternal and infant characteristics in the JECS were comparable to those in the national survey (14) .…”