Food insecurity is an important element in the poverty that is plaguing Nigeria. Dealing with the issue entails tackling the problems faced by the principal food producers, which are the rural smallholder farmers. Using the farming systems approach, this book focuses on an exposition of the underlying factors affecting food insecurity and poor living standard among rural families in the humid zones of Nigeria. Through multistage stratified sampling procedure, primary data was collected by field survey from 31 villages in Osun state. The analytical tools include descriptive statistics, econometric and the goal-programming model. Specific peculiarities of each household member was utilised for deriving calorie balance. Results show that poor living standard and food insecurity could be adduced to poor infrastructure, low input and resource availability. 59% and 41% of the households are calorie sufficient and deficient respectively. Modelling results reveal the negative impact of increasing risk factors that guides production decisions and some level of resource under utilisation and misallocation in actual practice partly adduced to risk avoidance behaviours therefore, the greater potential for farm families to be able to meet up with their food security goals through appropriate actions. Impact assessments show the need for improved cropping practices, credit facilities, land tenure changes and changes in the cocoa sector to improve food security.