The U.S Department of Agriculture (USDA) defines food insecurity as “uncertainty of having, or unable to acquire enough food to meet the needs of their members because of insufficient money or other resources for food at times during the year”. This book discusses patterns, prevalence and risk factors of food insecurity. Chapter One synthesizes the current literature on the prevalence, contributing factors and, the consequences of food insecurity in the United States; and presents a model framework to demonstrate the intersection of these consequences with health in vulnerable populations, as well as the implications for primary health care. Chapter Two explores why it is important for healthcare professionals to learn about food insecurity. Chapter Three commences with a brief description of the concepts and measurements of food insecurity, and presents the burden of food insecurity among the general population, and among HIV- infected, and HIV-affected populations. Chapter Four studies markets, methods, and options for improving safety and supply security of artisanally fished omena in Lake Victoria in Kenya.