U.S. health regulators warned units of Nestle and more than a dozen other foodmakers about overstating or misstating the nutritional value of baby food, nuts and other products on their labels.

Most of the letters made public on Wednesday accuse the companies of making claims on their food packages and websites over trans fat content, antioxidant advantages, and omega-3 benefits that fail to Food and Drug Administration guidelines.

The warnings come as the FDA is set to push for new package labeling to make it easier for people to understand the nutritional content of food.

While Wednesday's warnings are not indicative of labeling practices in the entire food industry, they should give food manufacturers further clarification about what is expected of them as they review their current labeling, FDA Commissioner Margaret Hamburg said in an open letter to the industry.

The FDA plans to issue draft guidelines for nutritional labeling and to work with the food industry on a new labeling system, she added.

The Center for Science in the Public Interest, a consumer advocacy group, urged the FDA to crack down on manufacturers that for far too long ... have exaggerated the healthfulness of their products.

New regulations should take a stronger stance on claims over trans fats and whole wheat as well as make the nutritional facts panel on the back of food packages easier to understand, the group said.

In a letter to baby food maker Gerber, a unit of Nestle, the FDA cited issues with Gerber 2nd Foods Carrot and Graduates Fruit Puffs products. It said their labeling includes unauthorized nutrient content claims.

The labels claim that the foods are Healthy as Fresh, an Excellent Source ... of Vitamin A and have No Added Sugar, according to the letter dated February 22. These regulations do not allow the claim for products specifically intended for children under two years of age, the FDA wrote.

The FDA issued a similar warning to Beech-Nut, a unit of Swiss company Hero Group, the same day.

A list of the companies that received letters and links to those letters can be found at: http://link.reuters.com/deb33j

Others receiving warning letters include snack food company Diamond Foods Inc, relating to the health claims for the omega-3 fatty acids in the company's walnuts, and Spectrum Organic Products Inc, a unit of Hain Celestial Group, over labeling for its vegetable shortening.

Nestle's Dreyer's Grand Ice Cream unit was warned over labeling of certain products.

A Nestle spokesman said the company was cooperating with the FDA but does not comment on pending regulatory inquiries.

Diamond expects to be able to make any changes required to packaging and the website expeditiously and with minimal expense, it said in a statement.

Hain and Beech-Nut could not be reached for comment.

The FDA wants the companies to immediately correct the products' labeling and respond to the agency within 15 days from the date of the letter. Most warning letters are resolved without further incident, although the agency does have the power to impose fines and other civil penalties.

Shares of Nestle closed down 1.8 percent in Europe. Shares of Diamond Foods closed down 1.6 percent, while shares of Hain Celestial closed up 1.7 percent, both on the Nasdaq.

(Reporting by Brad Dorfman in Chicago and Susan Heavey in Washington, additional reporting by Mihir Dalal in Bangalore; editing by Maureen Bavdek, Tim Dobbyn and Robert MacMillan)

Nestle Nestle