Some food dictates are so common that they are becoming second nature: eat local, eat organic, eat whole grains.
But make sure you eat certain foods together?
Rouge Tomate, a fine dining restaurant in New York City that prides itself on finding fresh ingredients and preparing them in a healthy way (that means no butter or cream, grilling or frying) is adding a new element to eating out.
An on-staff nutritionist makes sure that ingredients used in Rouge Tomate's dishes are paired in a way that maximizes their healthy benefits. Got a fish dish that is full of heart-healthy Omega 3? Nutritionist Natalia Rusin makes sure there's an ingredient like grapes, high in polyphenols, which will protect the delicate structure of the Omega 3 -- so the body can absorb more of it.
"It's going along with what our mothers have always told us: eat your fruits and vegetables. But now, we're finding a million scientific reasons for why we should actually do it," said Rusin, who has both a culinary and nutrition background. "The nation is full of nutrition-related diseases at epidemic levels, like high blood pressure and heart disease. This is so important."
Registered dietician and CBS Early Show contributor Keri Glassman said the idea of pairing nutrition-dense foods together is gaining popularity.
"The more we investigate, the more we learn about the complexities of food, and how food works together," she said.
For example, there's likely compounds in yogurt that helps the calcium to be absorbed better than if you took a calcium supplement alone.
One easy combo that's been shown to be complimentary is iron and vitamin C, Glassman said. If you are eating a spinach salad, try to use a citrus vinaigrette, and you'll get a lot more mileage out of the iron in the spinach, she said.
"You might already be eating a lot of these healthy foods, but by adding one other food you might up the benefits dramatically," Glassman said. "It's worth it to know about these other pairings."
Dietician Elaine Magee has written more than 25 books on nutrition and healthy cooking, and when she started seeing early research about food pairings, she wanted to be the first to write a guide on the subject. In her book "Food Synergy," Magee provides tips and recipes for nutrient-dense foods like whole grains and green tea, and pairs them together in menus to maximize their benefit. Magee also tailors menus based on foods that research links to preventing certain diseases, like breast cancer or heart disease.
Magee heard from other professionals in her field that she should have waited to write a book on food synergy until the research was more conclusive. But she thinks that as long as her recommendations make nutritional sense, like eating whole natural foods, that readers don't have anything to lose by giving her ideas a try.
"The ideas of components working together makes total sense," she said, citing research about how beta carotene wasn't as effective as originally thought when taken out of the context of a whole food, like a carrot. "The carrot had all the members of the carotene family that it was working together with."
David R. Jacobs, Jr., a professor of public health with the University of Minnesota, has researched food synergy for years. He said that there are so many nuances in the way that diet works that it's hard to know the exact benefits of food pairings. He's hesitant to be a proponent of a pairing like fish with grapes because of the polyphenols and Omega 3 benefit, because, like in a debate over carbs or "good fat," research could later prove contradictory. But, he said that the dish seems like a sound diet choice because of natural, rather than processed ingredients.
His idea of the best plan?
"Maximize nutrition per bite," Jacobs said. "Plant-centered meals are a good idea. Make sure the food you are putting in your mouth has good stuff in it."
And at Rouge Tomate, that's what Rusin is helping chef Jeremy Bearman do. Bearman and his sous chefs will come up with a dish, and then Rusin will try it, adding suggestions of how to make it healthier. Recently, the chefs came up with a dish of pasta with poached egg, peas and mushrooms. Rusin tried it, and then suggested adding chickpea flour and whole wheat flour to make the pasta healthier, bumping up the levels of fiber and protein to make it more nutrient dense.
"There are people that have come in here three or four times, and they don't realize that what they've been eating has been approved by a dietician," Bearman said.
But people like Magee, who lives in Northern California, hope the idea of restaurants that are putting such care into nutrition will spark a movement.
"These types of trends start happening in bigger cities and move across the country," she said. "Look at vegetarian dining. That wave made its way through, and those types of restaurants are everywhere now."
By Gina Pace