In an effort to manage their weight, many have switched to diet drinks. This may actually be even worse. Diet sodas may be free of calories but they are not free of health-related consequences. One study followed more than 400 diet soda drinkers for ten years. Results showed that their waist sizes increased seventy percent more than non-consumers. Those who consumed two or more diet sodas per day increased their waist sizes five times more than those who avoided diet drinks entirely. As waist sizes grow, so do health risks for diabetes, heart disease, and cancer. San Diego researchers, using brain imaging, showed diminishing activation of a brain area known as the caudate head as consumption of diet sodas increased. This brain area is associated with the food motivation and reward systems. Decreased activation of this brain region has been linked with elevated risk of obesity. Confusing the brain with artificial sweeteners may result in weight increases. A 2010 controlled study in rats found that those fed saccharin-sweetened yogurt ate more rat chow, gained more weight, and had more body fat than those who got the same amount of yogurt with a natural sugar (glucose), instead.