The preconception period has been recognized as one of the earliest sensitive windows for human development. Maternal dietary intake during this period may influence the oocyte quality, as well as placenta and early embryonic development during the first trimester of pregnancy. Previous studies have found associations between macronutrient intake during preconception and pregnancy outcomes. However, as food products consist of multiple macro- and micronutrients, it is difficult to relate this to dietary intake behavior. Therefore, the aim of this study was to investigate the association between intake of specific food groups during the preconception period with birth weight, using data from the Perined-Lifelines linked birth cohort. The Perined-Lifelines birth cohort consists of women who delivered a live-born infant at term after being enrolled in a large population-based cohort study (The Lifelines Cohort). Information on birth outcome was obtained by linkage to the Dutch perinatal registry (Perined). In total, we included 1698 women with data available on birth weight of the offspring and reliable detailed information on dietary intake using a semi-quantitative food frequency questionnaire obtained before pregnancy. Based on the 2015 Dutch Dietary Guidelines and recent literature 22 food groups were formulated. Birth weight was converted into gestational age-adjusted z-scores. Multivariable linear regression was performed, adjusted for intake of other food groups and covariates (maternal BMI, maternal age, smoking, alcohol, education level, urbanization level, parity, sex of newborn, ethnicity). Linear regression analysis, adjusted for covariates and intake of energy (in kcal) (adjusted z score [95% CI], P) showed that intake of food groups "artificially sweetened products" and "vegetables" was associated with increased birth weight (resp. (β = 0.001 [95% CI 0.000 to 0.001, p = 0.002]), (β = 0.002 [95% CI 0.000 to 0.003, p = 0.03])). Intake of food group "eggs" was associated with decreased birth weight (β = -0.093 [95% CI -0.174 to -0.013, p = 0.02]). Intake in food groups was expressed in 10 g per 1000 kcal to be able to draw conclusions on clinical relevance given the bigger portion size of the food groups. In particular, preconception intake of "artificially sweetened products" was shown to be associated with increased birth weight. Artificial sweeteners were introduced into our diets with the intention to reduce caloric intake and normalize blood glucose levels, without compromising on the preference for sweet food products. Our findings highlight the need to better understand how artificial sweeteners may affect the metabolism of the mother and her offspring already from preconception onwards.