color and appetite

The color blue is an appetite suppressant. Weight loss plans even suggest putting your food on a blue plate. This is because blue food rarely occurs in nature (ie bluberries). Thus humans have not developed an automatic appetite response to the color blue. In fact, due to the biological avoidance of poisonous foods, blue is a warning color in the food world. Our hunter gatherer ancestor avoided blue purple and black foods.

"Color and the appeal of various foods is also closely related. Just the sight of food fires neurons in the hypothalamus. Subjects presented food to eat in the dark reported a critically missing element for enjoying any cuisine: the appearance of food. For the sighted, the eyes are the first place that must be convinced before a food is even tried. This means that some food products fail in the marketplace not because of bad taste, texture, or smell but because the consumer never got that far. Colors are significant and almost universally it is difficult to get a consumer to try a blue-colored food -- though more are being marketed for children these days. Greens, browns, reds, and several other colors are more generally acceptable, though they can vary by culture. The Japanese are renowned for their elaborate use of food colorings, some that would have difficulty getting approval by the Food and Drug Administration in the United States."