Although evidence exists for an association between income level and diet quality, a causal relationship has not been established. A number of studies found that the price of nutritious food and the time cost to prepare foods are economically driven reasons for this relationship. However, in addition to economic constraints, low-income individuals and families face a number of additional challenges linked with food choice, eating behaviors, and diet-related chronic conditions that contribute to diet quality and health. Low-income individuals have a higher burden of employment-, food-, and housing-related insecurity that threaten the livelihood of their household. Poverty and exposure to these insecurities are hypothesized to activate biobehavioral and psychological mechanisms-endocrine, immune, and neurologic systems-that influence food choice and consumption. Examples of biobehavioral and psychological factors that influence diet are stress, poor sleep, and diminished cognitive capacity. High levels of stress, poor sleep, and cognitive overload compound the challenges of economic constraints, creating a mentality of scarcity that leads to poor diet quality.