Barbara Ferrer, Boston’s top health official, has railed against the perils of artery-clogging trans fat in doughnuts. She has exhorted the city’s youngsters, amid an epidemic of childhood obesity, to eat less, exercise more, and turn off the television.

So what to do on Halloween, a holiday that celebrates with abandon the delights of Snickers, Butterfingers, and Reese’s Peanut Butter Cups?

On Monday, she will fill two baskets for trick-or-treaters: one with stickers, trinkets, and packets of dried fruits; the other with candy. Most children, she knows from experience, will choose the sweets.

"While we don't encourage people to eat candy every day,'' said Ferrer, executive director of the Boston Public Health Commission. "We certainly realize there are special occasions.''

For parents regularly lectured on the importance of fruits and vegetables in their children's diets, Oct. 31, it seems, is one day to ignore those admonitions.

"It's the only time of the year when you get to eat a junkload of candy,'' said Thelma McAvoy of Dorchester, as she shopped for a Batgirl costume with her daughter, Hailey, 5.

The problem is, Halloween's candy cache can last weeks, said Joy Anastasia Gentry, founder of Reclaiming the Joy of Parenting, a consulting company.

And then, hot on its heels, comes Thanksgiving. And then, Hanukkah and Christmas, with their oil-laden latkes and gingerbread cookies.

"Unfortunately, it's not one day of the year,'' said Gentry, who lives with her 6-year-old son in Arlington. "Parents have to be honest with themselves about how much candy their kids are consuming before and after the holiday.''

Brandy K. Cruthird, founder of the child-oriented fitness program Body by Brandy 4 Kidz in Roxbury, threw a Halloween party Thursday night at her gym. Wait — a Halloween party at a gym?

There were no mini chocolate bars or even candy corn. Children ate apples and oranges, granola bars, and 100-calorie bags of Doritos. There was candy, but it was hard and sugar-free.

The point, Cruthird said, is not to deny children or adults fun on a holiday but to emphasize healthy treats — and habits.

Dr. Caroline Apovian, director of the Nutrition and Weight Management Center at Boston Medical Center, said Halloween can be a stressful time for parents looking to manage their children's nutrition — especially parents of overweight children.

Conversations about candy intake are fraught with concerns about body image.

"How do you tell an overweight child they can't have candy, when their friends are clearly indulging?'' Apovian said. The key: Don't try to eliminate candy, because desperate youngsters always find a way to get it. Instead, regulate it: a piece or two a night, always after a healthy meal.

The issue of Halloween candy has even sparked tension in the White House. While Michelle Obama directs a nationwide campaign to reduce childhood obesity, on Tuesday's "Tonight Show with Jay Leno,'' President Obama declared that his wife had gone too far, doling out raisins and other fruit when children arrive at the door.

"I said to her, 'The White House is going to get egged if this keeps up. We need to throw some candy in there,''' the president said. "A couple Reese's Pieces or something.''

To limit the quest for sugar, Gentry suggests putting the focus on decorating the house and playing Halloween games.

And teach children that it's OK to ditch some of their stash: Choose their favorites, and toss the subpar stuff.

"You and I both know that some of the candy you get is really bad candy,'' Gentry said. "But there's a tendency that, even if it's not a child's favorite candy, that candy stays around and eventually gets eaten.''

Maria Salazar, a Hyde Park mother of three daughters, said she understands the calls for a healthier Halloween. But no one wants to be the uncool parent parceling out the yucky goods to trick-or-treaters.

"I don't think I would ever buy raisins for Halloween,'' she said.

Copyright 2011 The Boston Globe