Most students enroll in general education introductory nutrition classes because they want to improve their diets in order to lose weight or enhance athletic performance. These nonscience majors are often less interested in learning about the fundamental biochemical principles underlying nutrition or are surprised that this foundational knowledge of biochemistry is essential for appropriate diet planning. Furthermore, nonscience majors sometimes find traditional, lecture-oriented science classes that encourage competition rather than collaboration to be uninviting and unappealing. For these reasons, we have developed a set of guided inquiry activities about macronutrients (carbohydrates, lipids, and proteins) and micronutrients (vitamins and minerals) for use in introductory nutrition courses for nonscience majors. In our first study (Spring 2012), we divided students into two groups with two different approaches for learning about the macronutrients: (1) a traditional, lecture-based approach and (2) an active learning approach with guided inquiry activities. We showed through the use of embedded common exam questions that students mastered concepts related to the macronutrients equally well using either approach. Due to positive student and faculty feedback from the first study, we decided to have all students use the guided inquiry approach in a subsequent study the following year (Spring 2013). In our second study we used pre/post survey data to evaluate both students' concept mastery and confidence in answering questions about the macro- and micronutrients. We found that (1) students showed gains in both concept mastery and confidence and (2) as students' confidence increased, post-test concept scores also increased.