Coca-Cola's attempt to sell healthier beverages isn't winning over friends in the health community.

In December the company received a warning letter from the Food and Drug Administration stating that its Diet Coke Plus labeling violates the Federal Food, Drug and Cosmetic Act. It seems that the "plus" part — trace amounts of vitamins and minerals — doesn't transform soda pop into a health elixir, as the company hoped it would.

Last month Coca-Cola received another notice, this time from the Center for Science in the Public Interest, which is suing Coke over what it calls deceptive health claims concerning the company's line of VitaminWater drinks. Could it be that VitaminWater — filtered water with ten packet's worth of sugar, food coloring, natural flavors and some vitamins thrown in for fun — does the body more harm than good?

Coca-Cola did not reply to LiveScience's request for an interview, nor has it replied formally to the FDA, but in an official statement the company called the CSPI lawsuit "ridiculous and ludicrous."

Coca-Cola isn't incapable of making healthy beverages. The company sells many unsweetened, healthy teas in Asia, including real green tea, not the sweetened concoction sold in the United States. The problem is that Coca-Cola has to reach the American consumer and, well, we love junk.

Plus what?

These days, in the nearly-anything-goes world of food marketing, you'd have to be just about bottling battery acid before the anemic FDA comes knocking with a warning. But is Diet Coke Plus really that bad?

The FDA's beef is with the product name. The word "plus" means something in labeling laws: The product must have 10 percent more nutrients than a comparable product. Diet Coke Plus likely has 10 percent more zinc and magnesium than, say, gin. Whether it has more of these minerals than ginger ale, though, is unclear, because Coke doesn't state what it is comparing Diet Coke Plus to.

Also, FDA policy deems it inappropriate — a substitute word for "unlawful" for an agency with no teeth — to fortify snack foods such as sweetened carbonated beverages and then market them as healthful.

Dumb water

Whereas many consumers are blessedly cynical enough to see labeling such as "Diet Coke with Vitamins & Minerals" as a joke, most would be surprised to know that VitaminWater has nearly as many calories and grams of sugar as regular Coke.

The hip labeling of VitaminWater disguises this fact. One serving has "only" 13 grams of sugar. But a serving is 8 ounces, and the bottle contains 20 ounces of liquid. So that's about 33 grams of sugar and 125 calories per realistic serving, compared to the 39 grams of sugar and 140 calories in a can of Coke.

Coca-Cola acquired VitaminWater and its sister products, SmartWater and VitaminEnergy, when it purchased the line of beverages from Energy Brands for $4.1 billion in 2007. Although CSPI is suing Coca-Cola, the company hasn't really tinkered with Energy Brands' longstanding, over-the-top health marketing, which claims that its various colors and flavors of VitaminWater can reduce the risk of chronic disease, reduce the risk of eye disease, promote healthy joints or support optimal immune function.

At best, VitaminWater is a marginally healthier alternative to soda pop. At worse, the calories and sugar promote obesity and diabetes. Moreover, the fruit flavors might imply that there is indeed fruit in VitaminWater. But despite names such as "defense raspberry-apple," "endurance peach-mango," and "xxx blueberry-pomegranate-acai," they contain between zero and 1 percent juice.

Truly smart water

Calories add up. In his new book "The World Is Fat," Barry Popkin, director of the University of North Carolina's Inter-Disciplinary Obesity Center, states that the average American gets 400 calories a day from beverages.

You don't have to forgo all Coca-Cola products for a healthy drink. Dasani is sort of a Coke "extra-light," with all the Coke ingredients stripped out except for the filtered tap water.

A meal with Dasani and vegetarian soup will have all the nutrition of VitaminWater without the added sugar and calories.

Christopher Wanjek is the author of the books "Bad Medicine" and "Food At Work." His column, Bad Medicine, appears each Tuesday on LiveScience.