At least three popular children’s cereals are packed with more sugar in a one-cup serving than a Hostess Twinkie, and an additional 44 are loaded with more sugar in a cup than three Chips Ahoy cookies, according to a study released Tuesday by the Environmental Working Group.

Kellogg’s Honey Smacks, Post Golden Crisp and General Mills Wheaties Fuel rank as the worst offenders based on the Twinkie measure, said the study , which analyzed 84 cereals. Other brands — including Honey Nut Cheerios, Apple Jacks and Cap’n Crunch — are among the 44 cereals that have more sugar in a cup than three Chips Ahoy cookies.

In nearly three-dozen brands, sugar makes up more than a third of the cereal by weight, the study said. Those include the original and “marshmallow” versions of Kellogg’s Froot Loops, as well as the original and “all berries” version of Quaker Oats Cap’n Crunch.

“Most parents would never serve dessert for breakfast, but many children’s cereals have just as much sugar or more,” said Jane Houlihan, senior vice president of research for the group, a nonprofit that researches everything from the safety of sunscreens to pesticides in foods. “I wasn’t surpised that so many of these cereals contained sugar. I was suprised at the very high amounts.”

The report comes at a time when the federal government is considering voluntary guidelines for foods marketed to children. With obesity rates at epidemic levels, a federal inter-agency group wants the industry to limit the sodium, fats and added sugars in the foods and drinks advertised to kids ages 2 to 17.

But the industry has lobbied against the proposal, which would take effect in 2016. Food companies say the guidelines are back-door regulations that would effectively ban food advertising to youth because they are so severe.

The guidelines allow for 13 grams of added sugar per 50 grams of cereal, so that a cereal can be about one-quarter sugar by weight. Two-thirds of the children’s cereals analyzed exceed that threshold, the Environmental Working Group said.

The industry prefers its own standard, unveiled in July, that calls for no more than 10 grams of sugar per listed serving size, starting in 2013. Most of the cereals analyzed now meet that threshold, but a quarter do not, the study said.

Many cereal makers say the study is misleading on several fronts.

For starters, only two cereals on the group’s “10 worst” list are marketed to kids, industry advocates said. Those two are Kellogg’s Apple Jacks and Froot Loops Original. Food firms stopped advertising products with more than 12 grams of sugar to children under age 12 starting in 2006, when the industry adopted its own marketing standards.

Honey Smacks is not marketed to children and seldom eaten by them, said Lisa Sutherland, vice president of nutrition at Kellogg North America. Neither is Wheaties Fuel, said Kirstie Foster, a General Mills spokesman. Its target audience is active male adults, Foster said.

Industry advocates also dismissed the comparisons between cereals and dessert, such as Twinkies with 17.5 grams of sugar and three Chips Ahoy cookies with 11 grams of sugar.

Even the sugary cereals, they said, are of nutritional value because they contain vitamins and minerals. Research shows that 40 percent of U.S. children consume their milk via cereal, said Sutherland of Kellogg. General Mills cites data from the Journal of the American Dietetic Association that says people who frequently eat cereal, including kids who eat sweetened ones, tend to have healthier body weights than those that don’t.

The study also ignores the progress made in reducing the sugars in children’s cereals, said Elaine D. Kolish, director of the Children’s Food and Beverage Advertising Intiative, which developed the industry’s self-regulation program. Cereal makers have cut sugar content from 10 to 25 percent since 2007, Kolish’s group reported.

Still, cereal companies can do much better, consumer advocates said.

For them, “this is about selling products. It’s not about health,” said Marion Nestle, a nutrition and food studies professor at New York University. “Their goal is to sell cereals, and these sugary cereals are enormously profitable.”

That’s why companies spend huge amounts of money advertising them, packaging them with colorful cartoon characters that lure children and placing them at eye-level on grocery store shelves, said Nestle, author of “What to Eat.”

Aside from the obesity issues tied to sugar, research also suggests that sugar is habit-forming and that children who eat high-sugar breakfasts have more problems at school because they are more easily frustrated and have a hard time working independently, according to the Environmental Working Group’s study.

But it was the climbing obesity rates that led Congress in 2009 to direct four agencies — the Federal Trade Commission, the Centers for Disease Control and Prevention, the Food and Drug Administration and the Agriculture Department — to look at how to improve the nutritional standards for foods marketed to children. The report might be presented to Congress by year’s end.

Obesity rates have more than doubled for children ages 2 to 11 and more than tripled for teens ages 12 to 19 in the past three decades.