The 19 best foods for health and happiness

If a single food was guaranteed to make you instantly slim or happy, or end your allergy woes, stores would have to fight back the feverish shoppers. We're not quite there yet, but there are foods and nutrients that science says benefit your well-being.

"Diet has tremendous effects on our short-and long-term health, especially when it comes to obesity, diabetes, and heart disease," says Dr. Dariush Mozaffarian, associate professor of cardiovascular medicine at Harvard Medical School.