The inverse relationship between higher rates of overweight women in lower socioeconomic groups has been established, yet its underlying reasons remain unclear. Possible causes fall into three categories. First, low SES could lead to higher BMI. Lower income is correlated with less education about nutrition and thus poorer diet. However, studies show that deeper cultural, behavioral, and economic factors correlated with lower SES also contribute to high BMI. Second, higher BMI could lead to lower SES. The discrimination theory states that heavier women are less valued and are blocked from earning opportunities and social networks. Third, biochemistry makes an impact in two ways. Genetic predisposition for obesity could explain how low income, high BMI women have low income, high BMI children. Another impact of biochemistry is weight cycling - the theory that episodic food disposition leads to increased rates of weight gain. For all three categories, public policy can play a role. Anti-hunger programs could focus on steady food supplementation instead of crisis intervention, in order to lower BMI. On a deeper level, policy-makers need a deeper understanding of the SES/BMI relationship to accurately address real issues of hunger among families who might appear well-fed. This deeper understanding requires further research.