This scoping review addresses gaps in the existing literature on dietary guidelines for pregnant and lactating women globally. The study delves into adherence levels, identifies influencing factors, and examines outcomes associated with these guidelines. Analysing food-based dietary guidelines (FBDGs) from around the world, the review reveals that half of the countries lack FBDGs, with only 15% providing tailored advice for pregnant and lactating women. Utilising data extracted from 47 articles across MEDLINE and EMBASE, the study highlights a scarcity of adherence studies, particularly in low- and middle-income countries (LMICs) and emphasises the lack of research during lactation. Overall adherence to dietary guidelines is low, with disparities in fruit, vegetable, whole grain, and fish consumption. Positive correlations with adherence include age, education, employment, social class, and certain medical histories, while negative correlations involve smoking, alcohol consumption, metropolitan residence, and elevated BMI. The study documented significant associations between adherence and reduced risks of gestational complications but calls for further exploration of intermediate nutritional outcomes like micronutrient deficiencies and child growth. Emphasising the urgency for globally standardised guidelines, especially in LMICs, this review provides a foundational call for prioritised studies and strategies to enhance dietary practices for pregnant and lactating women worldwide.