No one under 21 would be able to buy cigarettes in New York City, under a new proposal announced Monday that marks the latest in a decade of moves to crack down on smoking in the nation's largest city.

New York City Council Speaker Christine Quinn discussed details of a proposed law that would raise the minimum age for tobacco purchases from 18 to 21. City Health Commissioner Dr. Thomas Farley, some of Quinn's fellow City Council members and health advocates were to join her.

Under federal law, no one under 18 can buy tobacco anywhere in the country, but some states and localities have raised it to 19. Texas lawmakers recently tried to increase the minimum age to 21, but the plan stalled.

Public health advocates say a higher minimum age discourages, or at least delays, young people from starting smoking and thereby limits their health risks. But opponents of such measures have said 18-year-olds, legally considered adults, should be able to make their own decisions about whether or not to smoke.

Some communities, including Needham, Mass., have raised the minimum age to 21, but New York would be the biggest city to do so.

"With this legislation, we'll be targeting the age group at which the overwhelming majority of smokers start," Quinn said.

Officials say 80 percent of NYC smokers started before age 21, and an estimated 20,000 New York City public high school students now smoke. While it's already illegal for many of them to buy cigarettes, officials say this measure would play a key role by making it illegal for them to turn to slightly older friends to buy smokes for them. The vast majority of people who get asked to do that favor are between 18 and 21 themselves, city officials say.

"We know that enforcement is never going to be perfect," but this measure should make it "much harder" for teens to get cigarettes, Farley said.

The Richmond, Va.-based Altria Group Inc., parent company of Philip Morris USA, which makes the top-selling Marlboro brand, had no immediate comment, said spokesman David Sutton. He previously noted that the company supported federal legislation that in 2009 gave the Food and Drug Administration the power to regulate tobacco products, which includes various retail restrictions.

Under Mayor Michael Bloomberg and the health commissioners he has appointed, including Farley, New York has rolled out a slate of anti-smoking initiatives.

Bloomberg, a billionaire who has given $600 million of his own money to anti-smoking efforts around the world, began taking on tobacco use in the city shortly after he became mayor in 2002.

Over his years in office, the city — at times with the council's involvement — helped impose the highest cigarette taxes in the country, barred smoking at parks and on beaches and conducted sometimes graphic advertising campaigns about the hazards of smoking.

Last month, the Bloomberg administration unveiled a proposal to keep cigarettes out of sight in stores until an adult customer asks for a pack, as well as stopping shops from taking cigarette coupons and honoring discounts.

Bloomberg's administration and public health advocates praise the initiatives as bold moves to help people live better. Adult smoking rates in the city have fallen from 21.5 percent in 2002 to 14.8 percent in 2011, Farley has said.

But the measures also have drawn complaints, at least initially, that they are nannyish and bad for business.

Several of New York City's smoking regulations have survived court challenges. But a federal appeals court said last year that the city couldn't force tobacco retailers to display gruesome images of diseased lungs and decaying teeth.

Quinn, a leading Democratic candidate to succeed Bloomberg next year, has often been perceived as an ally of his.

Bloomberg also has pushed a number of other pioneering public-health measures, such as compelling chain restaurants to post calorie counts on their menus, banning artificial trans fats in restaurants, and attempting to limit the size of sugary drinks. A court struck down the big-beverage rule last month, but the city is appealing and Bloomberg has urged voluntary compliance in the meantime.

While Bloomberg has led the way on many anti-smoking initiatives, this one arose from the City Council, Farley said. City Councilman James Gennaro, who lost his mother to lung cancer after she smoked for decades, has been a particularly strong advocate.

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Mark Lennihan / AP

Harry Patel, an employee of Blondie's Deli and Grocery, talks on the phone while waiting for customers in New York on Monday. A new anti-smoking proposal would make New York the first city in the nation to keep tobacco products out of sight in retail stores. Mayor Michael Bloomberg says the goal is to reduce the youth smoking rate.

New York City Mayor Michael Bloomberg raised eyebrows Monday, proposing a new law – the first of its kind in the nation – that would require cigarettes and other tobacco products be hidden from view of shoppers.

“We know that out of sight doesn’t always mean out of mind,” Bloomberg said during a news conference at Queens Hospital Center. “But in many cases it can and we think this measure will help reduce impulse purchases and if it does, it will literally save lives.”

Experts say there is evidence that the mere sight of a pack of cigarettes really can make smokers want to buy them.

“Nicotine is the most addictive drug there is and cigarettes are both biologically and psychologically addictive,” says Dr. Gail Saltz, a NYC psychiatrist, author and regular TODAY contributor. “Seeing cigarettes is a trigger. ‘There it is.’ It very well may make you want it more.”

Numerous studies back this up. A 2008 study published in the journal Addiction surveyed nearly 3,000 adults (including smokers, ex-smokers and those currently trying to quit) and found more than 25 percent of smokers bought cigarettes after seeing a cash register display -- even though they weren’t shopping for smokes. And one in five smokers trying to quit said they avoided the stores where they usually bought cigarettes because they knew if they went in, they’d buy them.

The allure is so strong even 31 percent of smokers readily admitted that removing cigarettes from store displays would make it much easier to quit.

“Point of purchase cigarette displays act as cues to smoke, even among those not explicitly intending to buy cigarettes and those trying to avoid smoking,” wrote psychologist and lead author Melanie Wakefield, director of the Centre for Behavioural Research in Cancer in Victoria, Australia. “Effective POP marketing restrictions should encompass cigarette displays.”

Other studies have shown store cigarette promotions are strongly correlated with rates of youths taking up smoking as well as increased tobacco sales in the stores. A 2009 study in the journal Tobacco Control found that one of five shoppers who bought smokes at retail outlets with cigarettes on display at the check-out counter made an impulse buy.

“Visual triggers are a huge part of addiction,” says Joe Guppy, Seattle psychotherapist and addiction specialist. “That’s why when people are in recovery, they try to avoid visual triggers. I once had a client mention a magazine ad he saw once when he was trying to quit smoking. It showed a man taking that first drag off a cigarette, looking right into the camera. It probably took thousands of shots to capture that exact moment. But when it hit his brain, it made him go, ‘Oh, I want that so bad.’”

Adds Danny McGoldrick, vice president of research for Campaign for Tobacco-Free Kids, “Impulse buying can occur when you’re exposed to a number of different product displays but particularly if you have nicotine addiction.”

Guppy hails Bloomberg’s proposal, adding that “out of sight, out of mind” can be helpful with all kinds of addictions – from internet porn to sweets.

“I have a thing with chocolate,” he says. “If I want to moderate my intake of brownies, I’ll put them on top of the refrigerator instead of on the counter. That way, I’m not constantly triggered.”

Saltz warns that when it comes to something as addictive as nicotine, though, out of sight, out of mind may not always work.

“It’s not that simple because nicotine is addictive you’re going to seek it anyway if you’re already addicted,” she says. “But for people who may be trying to stay away and may not particularly be shopping for them, it would be better if it’s not in their face.”

Related:

• After big soda ban, NYC's Mayor Bloomberg wants to hide cigarettes
• Smoking costs you a decade of life
• A staggering teen smoking epidemic

Andrew Gombert / EPA

A large soda is filled at a restaurant in New York. A judge invalidated New York City's plan to ban large sugary drinks from restaurants, movie theaters and other establishments one day before the new law was to take effect.

A court may have ruled against New York’s supersized soda ban, but many prominent nutrition experts applaud any effort to limit how many sugary drinks Americans gulp down.

“There is really very clear evidence now that soft drinks are related to weight gain and obesity and, most certainly, diabetes,” says Dr. Walter Willett, a nutrition expert at the Harvard School of Public Health.

“We are in the midst of an epidemic of diabetes and obesity. The evidence is very clear that soda consumption has a role in the epidemic,” Willett added in a telephone interview.

“The evidence of harm for soda is longer than for anything else that we normally consume,” Willett says. “And there’s absolutely no benefit. Most foods, even if they are not the healthiest foods, have some nutritional value. Here it is all harm, no nutritional value. And the amounts being consumed are massive.”

The American Heart Association says Americans take in an average of 22 teaspoons of added sugar a day -- about 355 calories’ worth. It can have not just the obvious results, like obesity and diabetes, but also indirect harms: People who eat more sugar are also more likely to develop high blood pressure and other heart risks.

With two-thirds of Americans overweight or obese, it’s clear there is a problem. And a new study out Tuesday found that the more sugar-sweetened drinks that kids consumed, the more calories they got from other sources, too. In other words, kids who drink sugary beverages also eat other foods high in calories, the team at the University of North Carolina found.

"This is concerning because many foods that are associated with higher sugar-sweetened beverage consumption (e.g., pizza, cakes/cookies/pies, fried potatoes, and sweets) are also top sources of solid fats and added sugars; components of the diet that the 2010 Dietary Guidelines recommends Americans should limit," said nutritionist Kevin Mathias, who led the study, published in the American Journal of Preventive Medicine.

There’s no doubt Americans like to guzzle sugary drinks -- not just sodas, but sports drinks, energy drinks and fruit juices with sugar added. Beverage Digest estimates that Americans each drink 714 eight-ounce servings of carbonated soft drinks in a year -- that’s close to two a day.

Several studies have shown that the rate of type-2 diabetes has soared at just the same rate as intake of high-fructose corn syrup -- the favored sweetener in many soft drinks -- has risen. Soft drinks such as Coca-Cola were sold in 6.5-ounce bottles in the 1920s. Now the 12-ounce can is standard but fountain drinks are sold in sizes up to 64 ounces -- or the equivalent of eight of these cans of soda. One 64-ounce drink carries more than 800 calories.

All these giant servings send a message to people that it’s not only OK, but desirable to pig out, says nutritionist Deborah Kennedy, CEO of Build Healthy Kids and a co-author of “Beat Sugar Addiction Now! For Kids”

“Kids are eating their weight in sugar every year,” Kennedy told NBC News. “And sodas, energy drinks and sports drinks are the No. 1 source of sugar in kids’ diets. The message we are sending is ‘Jump right in’. What it says when these drinks are available is ‘Party time’.”  

New York mayor Michael Bloomberg has said he’ll appeal the judge’s ruling, which State Supreme Court Justice Milton Tingling Jr. called “arbitrary and capricious.”

The city’s ban had applied to “sugary beverages” larger than 16 ounces. “Sugary” is defined as a sweetened drink with more than 25 calories in eight ounces. Convenience stores, supermarkets and vending machine operators were exempted.

Willett says the ban was the right and proper thing to do. “It is the role of a health department to protect the public from these hazards,” he said.

Many experts would like to see much more regulation than this. Willett believes people should not be able to buy sodas with food stamps. “We published a paper recently showing the average adult on the (food stamp) program is consuming nearly three servings of sugar-sweetened beverages a day,” he said.

When he was still New York City's health commissioner, Dr. Thomas Frieden, now director of the Centers for Disease Control and Prevention, advocated for an extra tax on sugary sodas. He and Yale University’s Dr. Kelly Brownell wrote a 2009 commentary in the New England Journal of Medicine that called sugar-sweetened drinks the single largest cause of the U.S. obesity epidemic and argued that a 1 cent per-ounce tax would lower consumption by 10 percent.

The Center for Science in the Public Interest calls soft drinks “liquid candy” and wants rules that would label them the way cigarettes are labeled now -- with health warnings. "Parents and health officials need to recognize soft drinks for what they are -- liquid candy -- and do everything they can to return those beverages to their former role as an occasional treat," the group says.

Kennedy agrees.

“Kids know that too much sugar isn’t good for them,” she said. “But they don’t have the support in the community to help them make that healthy decision.’

Kennedy and Willett both noted that the beverage industry is fighting back hard against efforts to regulate soft drinks, both by lobbying lawmakers and with high-volume, expensive advertising.

“The ads suggest that drinking soda will make you congenial. You’ll be more athletic, while the real image should be losing limbs, losing vision and other images of diabetes,” Willett said.

“One of the newer things that soda companies are doing is they are putting vitamins in the soda, which to me is atrocious because it sends the message that it is a healthy drink,” Kennedy said.

Want to know how much sugar you’re getting in a drink? Harvard has a chart online here.

Related links:

• New York passes ban on big sugary drinks
• Yes, you can get kids to cut sodas
• Seven awful things diet soda does to you

John Makely / msnbc.com

Judy Laurini, left, and Gem Sumner, right, laugh about their 24-ounce sweet teas that they bought from McDonald's on Sixth Avenue.

NEW YORK -- Mayor Mike Bloomberg wants to limit the size of New Yorkers' sugary drinks, but the initiative is not going down very well with people in the city, including visitors interviewed on Thursday.

The ban on the sale of any cup or bottle of a drink larger than 16 fluid ounces – a little bit bigger than the size of a soda can – would include a range of sweetened drinks sold at restaurants and food carts, according to the mayor’s office.  The New York Times, which reported on the initiative, said the proposal could go into effect as early as next March.

The mayor noted that 58 percent of adults in the city (and nearly 40 percent of public school students in grades K-8) are overweight or obese. Obesity costs $4 billion a year in health care costs and kills thousands of New Yorkers, his office said.

But that rationale didn’t fly with many out for lunch or a stroll in the city’s midtown district.

“I don’t need the government on my meal plate or in my beverage,” said Travis Humphrey, a 30-year-old who works in tobacco prevention from Norman, Okla.

He said he was “very reluctant” to have such regulations imposed on businesses and their products though he welcomed the effort to work on serious health issues. “This is something that I am not exactly sure if government regulation … is going to be the solution.”

A pair of friends in town drinking sweet teas in what appeared to be 24-ounce size cups also denounced the mayor’s effort.

“I wish the government would get out of it and stay out of our lives and allow us to make the choices,” said Judy Laurini, 68, of Rochester, N.Y., who advocated that he spend money on educating people about the health problem.

“I’m an adult, I can drink it if I need it,” chimed in her friend, Gem Sumner, 68, of  Seattle, Wash. “But I would not let my children,” she added, laughing.

A man who didn’t want to identify himself derided the effort and the mayor’s earlier anti-smoking law, calling him, “Dr. Bloomberg,” and saying it felt like a “police state.”

“I think he’s a little bit out of line. I don’t think he’s got the right to sort of dictate what people can and cannot drink,” Carolyn Summers, a 46-year-old New Yorker who works in finance said as she held a large cup of unsweetened tea. “I can see that concern about obesity but I think that people need to be responsible for themselves.”

The mayor’s office said the ban would build on his previous health initiatives, such as banning smoking in public places and having calorie content posted at chain restaurants. It said those had improved life expectancy by nearly three years in the city famous for its pizza slices and hot dogs.

John Makely / msnbc.com

Bonita Troia, 35, a paramedic and her son Carlos Lopez, 17.

“We have an obligation to warn you when things aren't good for your health,” he told MSNBC’s Andrea Mitchell. “So here the idea is, if you have to take it in a smaller glass, you’ve got to make a conscious decision to have another cup of it. And, we think a lot of people won't and therefore that will reduce one of, and it’s only one of, the contributors to the obesity epidemic that’s going on in this country.”

Bonita Troia, a 35-year-old paramedic from Kingsville, Texas, said she agreed with the mayor, especially since in her work she sees 500-pound adults and children who weigh 200 or 300 pounds.

“When we grew up in the ‘80s the portions were smaller and people weren’t that big,” she said as she ate lunch with her teenage son. “The portion sizes have been getting bigger so people got bigger.”

“People just don’t discipline themselves,” she added.  And, “us as taxpayers are paying for what people are putting on their plates.”