As the science of nutrition continually evolves, researchers recognize that nutrients needed to maintain a healthy lifestyle must be tailored to the individual for maximum effectiveness. Recognizing that people are not all alike and that one size does not fit all when it comes to planning and achieving a healthful diet, the Institute of Medicine's dietary guidelines, titled "Dietary Reference Intakes for Macronutrients," stress the importance of balancing diet with exercise and recommends total calories based on an individual's height, weight and gender for each of four different levels of physical activity.

The delivery of nutrition education reached women across all life stages and through many platforms. Many nutrition education studies that targeted pregnant and lactating mothers reported on women's outcomes, but the primary focus of many of these studies was child health outcomes (13, 14, 19, 21, 24, 28); few studies focused on dietary outcomes and behaviors of pregnant and lactating women themselves (17, 20, 23). There were some studies evaluating the impact of nutrition education on the practices and outcomes of school-age children and adolescent girls (15, 18, 27, 29, 34), as well as older women (16, 22, 25, 30). Many of the nutrition education interventions were clinic-based (17–20, 23, 24). However, nutrition education was also delivered through community-based programs, including home visits (16, 21), community centers (15, 16, 20, 21), worksites (25), and schools (25, 27, 30, 34).