In an effort to begin filling a gap in the scientific literature about community-based food systems and promote food environment changes to increase dietary quality, this dissertation focuses on community-based food systems research with two different populations: Head Start families in southwest Virginia and Heifer International Alternative Spring Break (ASB) college student participants at Virginia Tech. Fresh Produce, Fresh Start (FPFS) tested the effectiveness of a local, fresh fruit and vegetable delivery program on dietary intake and purchasing patterns of Head Start families. FPFS utilized a one-group double pre-test post-test was conduced on two occasions at each of the two sites. Measures collected included: food-use questionnaire, height and weight, food security questionnaire, 24-hour recall, program process evaluation, and food receipts. Fifty-one of 67 (76%) of eligible participants were recruited. For dietary recalls completed (n = 29, 57%), significant increases were found in intake of vitamin A, vitamin C, fiber, vegetable, and fruit and vegetable (FV) servings combined, based upon paired t-tests (p <.05). Based on receipt data (n = 22, 43%), the proportion of fresh produce purchases significantly increased for both number of items and monetary costs, based upon a Wilcoxon Signed-Ranks Test (p < .05). A second study was conducted to examine the impacts of the Heifer Alternative Spring Break (ASB) programs on Virginia Tech student's attitudes, motivations, diet, and behaviors regarding community-based food systems before and after a one-week intensive program. The design was quasi-experimental, using a one-group pre-test, post-test, and follow-up. Participants completed questionnaires, dietary recalls, and journals. Forty-three of 43 (100%) of eligible participants enrolled in the study. Although increases in local and organic foods were observed, there were no significant changes in dietary quality. The intervention showed significant increases in local and organic food consumption for individuals that consumed less than 50% of their calories from local and organic foods at baseline based upon a paired t-test (p < .05). The findings from these studies offer evidence of the capacity for community-based food systems to change dietary patterns, across different populations. / Ph. D.