3.2. Total energy intake to nutrient energy ratio
The purpose of this study was to explore the effect of nutrient energy supply ratio on TAG composition of breast milk by food frequency questionnaire. The total energy intake and nutrient supply ratio of the three groups are shown in Table 1. The total daily energy intake in the fat group was 2106.07 kcal in the mothers, 2189.21 kcal in the carbohydrate group, and 2246.35 kcal in the protein group. There was no significant difference in total energy intake among the three groups (P > 0.05). Each group had and only one nutrient function ratio was significantly higher than the other two groups. The fat energy ratio and protein energy ratio were significantly different among the three groups of mothers (P < 0.05). The carbohydrate energy ratio of mothers in carbohydrate group was significantly higher than that in fat group and protein group, but there was no significant difference between fat group and protein group.
Referring to the 2022 Dietary Guidelines for Chinese Residents (Dietary Guidelines for Chinese Residents , 2022), the total energy intake of all mothers was lower than the dietary energy requirement of lactating mothers (2300 kcal/day). Only the carbohydrate intake of lactating mothers in the carbohydrate group (~57%) was within the acceptable range of macronutrients (50-60%), and the carbohydrate intake of the other two groups (~45% and ~43%) was below the lower limit of the range. In addition, the fat intake of lactating mothers in the three groups was higher than the upper limit of the acceptable range of macronutrients (20-30%), especially the fat intake of lactating mothers in the fat group and the protein group was too high (~40% and ~36%).
Lipids are known as a major source of energy, and a diet composed mainly of lipids can provide more energy for future generations (Mehta, 2008). A mother ’s high-fat diet increases the concentration of milk fat, especially LCFA and MCFA, leading to a fuller transfer of this macronutrient to the infant (Seet et al., 2015). In an early report, it was observed that a high-fat diet can promote the development of the hippocampus by stimulating neurogenesis and reducing apoptosis (Li et al., 2017). However, some studies have shown that maternal high prenatal intake of sugar and prenatal or postpartum intake of saturated fatty acids are associated with increased obesity (Gomes et al., 2018) in offspring. But this excessive fat intake is consistent with two studies (Chen et al., 2012; Tian et al., 2019; Hui-Min et al., 2019) conducted in southeastern and northeastern China, which may be related to the nature of postpartum eating habits in China. This postpartum practice refers to increasing the consumption of high-fat and protein-rich foods, such as chicken soup and pig hoof soup etc . It shows that Chinese lactating women need to follow a more balanced diet, especially emphasizing less fat intake.