Let's get one thing straight: This is a picture of a food triangle on the side of a pyramid.

The "pyramid" above was released by the USDA in 1992, and it suggests there is one ideal strategy for healthy eating that everyone can follow. That strategy, it suggested, was to load up on breads and pastas, eat ample servings of fruits and vegetables (three to five per day), and round out one's diet with some dairy and protein from sources like meats, nuts, and beans.

But researchers are discovering in study after study that what works for one person may not be right for everyone else. Different bodies respond differently to ingested fats and carbohydrates, so a stable energy source for one person could lead another's blood sugar to skyrocket then crash.

Nutrition experts generally agree, however, that everyone can benefit from eating more unprocessed foods, like leafy greens, seafood, nuts, and brown rice, while cutting out the processed white bread and crackers found on the bottom of this triangle.