Introduction Nowadays, the influence of maternal nutrition on different aspects of labour and fetal health is widely investigated. Optimal life style and proper diet are recommended to decline the risk of birth defects (1). Dietary advices should be offered to women for promoting their child health and weight (2). It is believed that restricted nutrition could interfere with physiologic adjustments of pregnancy, cause fetal developmental impairment, induce labour, and increase the risk of gestational diabetes mellitus (3, 4). In addition, the ability to have an effect on offspring sex is an issue that is often considered by the parents from past until now. A number of reasons have been mentioned for sex selection including family planning, cultural background, parental preference of a specific gender, and prevention of the sex-linked genetic diseases. Natural and technical methods such as diet, timing of sexual intercourse, prefertilisation sperm sorting, and pre-implantation genetic diagnosis (PGD) are available for sex selection. Except for sex selection for medical indication that must be done by PGD with 100% accuracy, cost, ethics, and society believes propel the parents to use nutrition (5). According to some hypotheses, healthy and nourished mothers mostly give birth to the boys; meanwhile, the sex ratio at birth is found to be affected by maternal socioeconomic conditions including the nutritional status (6, 7). This study aimed to evaluate the publications on the relationship between maternal nutrition and sex of the offspring in humans. Materials and Methods Data Sources A systematic literature search was performed across international electronic databases (e.g., ISI Web of Knowledge, PubMed, Cochrane Library, and Scopus) with no time limitation using predetermined keywords. The English search strategy is shown in Table 1. Study Selection Selected publications included original articles in English with different methods and population sizes regarding preconception maternal diet, nutritional status, fetal sex, or sex ratio in humans. In addition, a number of data were excluded from the study including reviews, letters to the editors, commentaries, editorials, experts' opinions, and publications without available electronic full texts. After initial search using search terms strategy, the related publications were selected focusing on the title/ abstract review. Following excluding duplicate articles, full