According to recent research from Cornell University and the University of California-Davis, poor women may be more prone to obesity due to their habit of periodically going without food in order for their children to eat. Also, many low-income families can only afford to purchase high-calorie, processed foods because they are less expensive (such as fast food "value meals.") Many poor urban neighborhoods lack access to grocery stores that provide nutritious foods, while these areas also may not have access to safe areas for physical activity.