Last night at the Emmy's, award winners were served french fries and ketchup behind the scenes. The snack came courtesy of McDonald's, which was promoting the imminent launch of its all-day breakfast. And it was, in all likelihood, irresistible.

After all, few things are as beloved in the United States as french fries and ketchup, a combination that has imprinted itself so firmly in the American diet that it has helped create a disconcerting imbalance in the vegetables people eat.

"Americans consume a lot of a certain two vegetables, instead of having a good variety,"said Jeanine Bentley, who is an analyst at the Department of Agriculture's Economic Research Service.

The two vegetables Bentley is talking about are those that were featured—albeit in their highly processed form—backstage at the Emmy's: potatoes and tomatoes. And new data from the USDA shows that they are, indeed, anomalies in the world of American vegetable consumption. Incredibly, the two account for almost half of all vegetables eaten in the United States--and often, they aren't fresh from the market but frozen and preserved.

For starters, USDA data showed that about a third of all vegetables consumed by Americans are potatoes, while more than a fifth are tomatoes.

What's more, preserved and frozen potatoes and tomatoes -- the bread and butter of the American diet -- are making it into an overwhelming number of breakfasts, lunches, and dinners in the United States. Some 70 percent of all potatoes consumed in the United States by weight are frozen or processed, according to the USDA. For tomatoes, the portion is roughly 77 percent.

That's thanks, in no small part, to the ubiquity of fried potato sticks and one famously popular, cloyingly sweet, tomato-based condiment, says Bentley.

Asked whether the two foods were significant contributors to the imbalanced American diet, Bentley said: "Oh yes, definitely."

"Tomatoes for processing, that's mainly ketchup, and then other tomato sauces," she added. "Potatoes, I think, are largely french fries and chips."

The USDA's own data on the particularities of potato consumption show exactly what Bentley is talking about. More than half of all potato sales go to "processors of french fries, chips, dehydrated potatoes, and other potato products," the agency says on its website. This bit, taken from the page, is particularly telling:

Spurred by the innovation of frozen-french-fry processing techniques in the 1950s and the increasing popularity of fast food chains, processed potatoes composed 64 percent of total U.S. potato use during the 2000s (compared to 35 percent in 1960s). During the 2000s, U.S. per capita use of frozen potatoes has averaged 55 pounds per year, compared to 42 pounds for fresh potatoes, 17 pounds for potato chips, and 14 pounds for dehydrated products.

Potato chips are the most eaten form of potatoes at home, according the the USDA. But elsewhere, it's french fries.

For tomatoes, the impact of ketchup has been similarly significant. The condiment, which the USDA refers to as catsup, accounts for roughly 15 percent of all tomato consumption in the United States.

The data, amusing as they are, are troubling, too. Potatoes and tomatoes aren't terribly nutritious on their own. Ideally, Americans would be consuming a much more varied array of vegetables and legumes.

"The Dietary Guidelines promote variety," said Bentley. "But Americans clearly aren't getting a healthy variety of nutrients."

A recent survey by the Centers for Disease Control shows that very few Americans eat as many vegetables as they should. The study found that almost 90 percent of adults in the United States failed to meet government recommendations for vegetable intake.

A report released by the USDA last year highlighted that even when Americans eat vegetables, they tend to eat them in less than ideal forms. "Instead of eating vegetables in their simple, unadorned state, Americans often eat vegetables prepared in ways that add calories and sodium," the report says.

The country's love for french fries and ketchup, neither of which offer much in the way of nutrition, aren't helping. French fry consumption, has been associated with an increased risk of type 2 diabetes.

The World Health Organization, meanwhile, has implored that countries like the United States (where people consumed more sugar than anywhere else) work to lower sugar intake, and called out ketchup as an example of a significant but "hidden" source.