Book excerpt: Economic and physical access to healthy and nutritious foods have been targets of public policies worldwide. While the policy emphasis may differ depending on the country, the end goal is to achieve food security for all. This thesis, organized in two essays, is an attempt to contribute to understanding the factors affecting the access to healthy foods and their implications for the households' food security. The first essay focuses on the issues contributing to rising food prices. The research uses time series analysis of monthly food prices in Togo over the period 1998 to 2017 to determine first, the levels of unconditional and conditional volatility in major food commodity prices, and then, the drivers of those price changes. The results reveal that fluctuations in food prices, as measured by volatilities, has increased in the last ten years. In addition, the results of Autoregressive Distributed Lag (ARDL) and Error Correction Models (ECM) estimations indicate that the observed price variabilities of food commodities in Togo may depend on the agricultural production seasonality and domestic fuel price. The findings suggest that any policies that stabilize the domestic fuel price and that address the seasonality of the agricultural markets will most likely contribute to stabilizing the market prices of food commodities. The second essay focuses on healthy diet issues. The study is an empirical analysis to identify potential determinants of healthy food consumption in the United States using the USDA ERS Food Acquisition and Purchase Survey (FoodAPS) data on households' food acquisitions and health. Two diet quality indices, the Healthy Eating Index (HEI) score and the primary food shopper assessment of households' diet are used in the analysis. The results suggest that food shopping at superstores and supermarkets, higher income, eating home cooked meals more frequently, and a higher education level are associated with a healthier diet quality. Conversely, the distance from the nearest food store may adversely affect households' diet quality. The implications of the study are that improving economic as well as geographic access to healthy food stores and promoting nutrition education in the United States are likely to promote healthier diets.