A growing number of cities are turning their attention to the nutrition that they offer employees and visitors, particularly through vending machines. Philadelphia's plan is a bit more comprehensive than others: Vending machines will offer soda in smaller sizes, placed them lower in the machines, and sell them at a higher price than bottled water. The moves change the environment in which food purchases are made, said Gary Foster, director of Temple's Center for Obesity Research and Education. "Government often tells people what they should do: 'Eat more of this, drink less of this,' but we don't help people with the how. What this policy effectively does is make the decision to eat healthier easier," he said. "