Some of my patients report a strong urge to eat carbohydrate-containing foods, such as sweet, sugary things, especially when they feel blue, down, or depressed. This is generally thought to be the carbohydrate-craving syndrome. Eating carbs helps increase serotonin in the brain, which is a feel-good hormone. A study published in the journal Eating Behaviors in October 2008 lends more support to this carb theory linking food and mood. Study participants were able to choose a carb-laden beverage over the protein beverage. Both beverages were designed to look and taste the same, so there was no overt difference detectable. In the end, the carb cravers were more likely to select the beverage with more carbs than protein.