In her darkest days, Elena Santaballa painstakingly planned her binges. She surreptitiously purchased her stash. She hid the evidence. Even when trying to resist the temptation to use, she almost always succumbed.

Finally, three years ago, the Culver City woman acknowledged that she was hooked on sugar.

"It's like being an alcoholic," says the 37-year-old entertainment executive, who was extremely overweight when she joined a 12-step treatment program. "There is always the danger I'll go back to it if I don't have some sort of support program. I still struggle with wanting to use sugar as a drug."

The concept of sugar addiction has been popularized in books -- and joked about -- for decades. But most health experts have long maintained that overuse of sugar doesn't meet the criteria of addiction, typically described as an intense desire for a substance (so that it disrupts normal life), great difficulty stopping use of the substance and a severe physiological response upon withdrawal. People who are addicted, they add, lose control over their behavior and use a substance compulsively and repetitively in spite of adverse consequences related to their actions.

Now researchers are finding what many sufferers have long suspected -- the compulsive overeating of sugar does at least share some of the characteristics of more destructive addictions. Their work is shedding light on the neurological response of those who abuse sugar.

In a widely discussed study presented earlier this month, for example, Princeton University psychologist Bartley Hoebel showed that rats will not only eat sugar excessively, they suffer from withdrawal when denied sugar and continue to crave it weeks later.

Addiction 'plausible'

Most of the studies so far have been in animals. But researchers at Columbia University will soon launch a study focusing on sugar dependency in bulimics -- people who binge (usually on rich, sweet food) and then purge.

"There are people who have pathological, clinical eating disorders who say they are addicted to chocolate and other sweets. And you know what? They may be," says research nutritionist Adam Drewnowski, director of the Center for Public Health Nutrition at the University of Washington. "I think it's plausible."

So does Kathleen DesMaisons. Many of the people she counsels fit at least some of that description. DesMaisons, who calls herself a "recovering sugar addict," is a leading proponent of the theory of sugar addiction and the author of "The Sugar Addict's Total Recovery Program." DesMaisons was managing a treatment center for alcoholics when she began to see similarities between alcoholism and compulsive overeating.

"When you're addicted to sugar, you need more to feel better," says DesMaisons, who runs a Web site on sugar addiction from her home in Albuquerque. "Your life starts being focused on getting a sugar fix. You have symptoms of withdrawal, which is craving. You get antsy, irritable and cranky. To dismiss the experience of thousands and thousands of people who say they feel this way is pretty silly."

The average American adult consumes about 158 pounds of refined sugar a year, according to the U.S. Department of Agriculture, a figure that has increased 25% in the last three decades as the popularity of high-sugar-content convenience foods grew. Most people simply like sweets. But for others, the desire for sugar becomes extreme, similar to those hooked on cocaine, alcohol or other chemicals, says DesMaisons.

"They lie about how much they use," she says. "They hide evidence, like candy wrappers. They'll go out at 11 p.m. to buy a pint of ice cream."

And they flunk the chocolate-chip cookie test. While many people would eat -- and savor -- a few freshly baked cookies, sugar junkies would embarrass themselves.

"Imagine a plate of cookies just out of the oven. People who are addicts start laughing at the thought of that. They would eat the whole plate," she says.

Terri Walker says her feelings of worthlessness and depression made her realize she had a problem.

"I would say 'I'm not going to eat it,' and the next thing I knew I would talk myself out of it," says Walker, 35, a warehouse clerk in Barstow who was about 20 pounds overweight and, she says, suffered from fatigue, low energy and poor self-esteem. "Then I would kick myself because I had no willpower. I had feelings of shame and failure. A lot of the addictive behaviors that people would attribute to other types of addiction: hiding things, hoarding, being overly upset when someone ate your goods-- I've done all that."

People who call themselves sugar addicts also say the recovery process mirrors drug and alcohol addiction.

"When I eliminated sugar from my diet, I went through a detoxification," says Santaballa, who gave up eating all refined sugar. "I had flu-like symptoms, the shakes, headaches, and I was exhausted for 30 days. Sometime within the first 10 days I became craving-free. I still had the behavior of wanting it, but the physiological craving went away."

Nutritionists typically dismiss the notion of sugar cravings because the body metabolizes sugar the same way it does all carbohydrates, whether they are from doughnuts or bread or fruit or vegetables.

"The form of carbohydrate that is eaten doesn't matter because the body breaks everything down into [sugar] anyway," says Richard Surwit, chief of medical psychology at Duke University Medical Center. "The brain cannot burn anything but sugar. That's the only thing it uses for metabolism. So saying the brain is addicted to sugar is like saying a gasoline engine is addicted to gasoline."

But evidence also suggests that sugar can negatively alter brain chemicals.

Drug-like action on brain

Studies by Drewnowski in the 1980s offered some evidence that the brain's response to sugar cravings is similar to that provoked by heroin or cocaine.

Addictive drugs stimulate receptors in the brain to release natural opiods and dopamine, neurochemicals that trigger feelings of pleasure or well-being. In Drewnowski's experiment, when chocolate lovers were given a drug, naloxone, that blocks the opiod receptors, they no longer craved chocolate.

"A strong preference for fats and sweets may reward opiod mechanisms in the brain. But we can't say that this happens to everyone," he says, noting that the preference is much more common in women than men.

He also points out that intense sugar cravings are actually yearnings for sugar and fat. "Sweet treats are rarely just sugar," says Drewnowski, one of the nation's leading authorities on taste preferences. "They are usually a mixture of sugar and fat -- ice cream, cake, doughnuts. Watermelon is [full of sugar], but no one craves that. However, when you bring sugar and fat together, there is this kind of synergy."

What the body appears to crave is the combination of high-energy foods that also pack some hefty calories, he says. This fix of sugar and fat often produces the well-known "sugar high."

Meanwhile, Hoebel's research found that rats, when denied food for 12 hours, binged on a sugar solution when presented with a choice of regular rat chow or sugar water. The rats gradually drank more sugar water and ate less chow and showed signs of withdrawal when the diet was stopped -- such as teeth chattering and being more fearful while navigating an elevated maze.

Increasing use of a substance and withdrawal symptoms are two characteristics of a dependency. But, says Hoebel, "to really call something addictive, you need to show there is a heightened motivation, or craving."

In a study presented earlier this month at the Society for Neuroscience meeting in Orlando, Fla., Hoebel demonstrated that three weeks after resuming a regular diet of rat chow, the rats frequently pressed a bar that had been used to release the sugar solution. Although denied more sugar water, the rats' behavior indicates an "exaggerated" motivation for the substance, Hoebel says.

"This is evidence that there are changes in the brain that last," he says. The rats' behavior "is beginning to meet the full definition of addiction."

Others downplay the animal research, saying that humans don't show withdrawal symptoms. In his research, Surwit put one group of people on a sugar-free diet and another on a low-fat diet that contained 50% of calories from sugar. After six weeks on the diet, both groups lost the same amount of weight and the dieters eating lots of sugar showed no behavior changes while on the diet and no ill effects after stopping it.

Emotional factors cited

Still, no one knows why certain people dramatically overeat sugary foods. Genetic predisposition, learned behavior and, perhaps, underlying emotional issues are likely factors, experts say. Based on the rat study, Hoebel suggests that a destructive sugar habit may be established by a pattern of sugar deprivation followed by bingeing -- a practice common among bulimics.

Clearly, some people can crave sugar, eat a cookie and be satisfied while others continually flunk the chocolate-chip cookie test, says Drewnowski. Intense emotional feelings may override a resolve to resist sweets.

"When someone sits down alone and eats two pints of vanilla ice cream and is not able to stop, that is a problem," he says. "Your body is trying to tell you something -- probably that you're too stressed or depressed."

Research is a long way from helping people who compulsively crave sugar. A medication is available to block opiods. But, says Drewnowski, "It's used to prevent alcoholic binges. No one is going to use it to prevent bingeing on ice cream."

He advocates cutting sugar consumption and avoiding refined sugar, as well as counseling for underlying emotional issues that might trigger binges. Many of the popular books on sugar addiction, such as DesMaisons,' promote abstinence from foods containing refined sugar.

"The proof is in the pudding -- the pun is intended," says Santaballa, who has lost 100 pounds after several years on a no-refined-sugar diet.

"When I accidentally ingest sugar, I am crawling out of my skin. My body knows it's there. There's nothing you can do to convince me this is not an addiction."