In this study, we focused on food intake before and during pregnancy and its effects on birth weight. We conducted a survey of mothers' physical status, smoking, drinking habits, food intake and children's physical status for 1,302 mothers who participated in health checkups for 3 or 4 month-old infants. In the low birth weight infant group, mothers had low weights at non-pregnancy and childbirth. Non-pregnancy BMI, weight gain, height at birth and gestational age were also low and mother’s smoking habits were frequent. Further more, the low birth weight group had lower vegetable food intake scores for both before and during pregnancy in the intake score calculated from the frequency and amount of food intake. Compared with the high score groups of vegetable and milk/dairy product intake on pre-pregnancy, low score groups had higher odds of having low birth weight (OR1.69, 1.58). We suggest the need for proper dietary management before pregnancy to control low birth weight, especially thorough guidance on vegetable intake.