By Danielle Dellorto, CNN

Copenhagen is a bustling city full of ambitious professionals and young families. Yet working long hours here is frowned upon.

Just 2% of employees in Copenhagen work 40 hours a week or more, according to an OECD report, freeing them up to spend time with family, join organized sports, volunteer or participate in other community programs.

The cost to participate in those programs, which range from laughter yoga in the park to basket weaving? Free. This helps encourage residents to get involved.

Their ability to balance work with quality time with friends and family not only keeps their stress levels down, it gives them a happiness boost. Studies show that people who focus on experiences versus things have higher levels of satisfaction long after the moment has passed. That’s one reason Denmark takes the top spot as the happiest nation in the annual World Happiness Report commissioned by the United Nations.

Other things play into Copenhagen's relaxed atmosphere. Residents walk to restaurants and walk to get groceries. There are outdoor food markets with fresh produce and vegetables within a few blocks of most spots in the city.

Men cycle to work in their slim-fit suits, and women don’t shy away from pairing a bike helmet with their sundresses and wedge heels. The city has 249 miles of bike paths, which makes biking an easy and safe option. And people use them: Nearly half of commuters in Copenhagen travel to work or school by bike each day.

Though parks and bike paths are plentiful, the government is upping its efforts. By 2015, all residents must be able to reach a park or beach by foot in less than 15 minutes, according to a new official municipal policy. Many of the new parks created will be “pocket parks,” or small green spaces for city residents. The hope is that they will help keep residents fit and help the environment by reducing traffic and pollution.

Here’s one more stat that may make you want to start packing your bags for Denmark: Ninety-six percent of residents in Copenhagen say they can count on someone if they are in need.

This supportive society is just another reason Copenhagen earns a spot as one of the healthiest (and happiest) cities.

By Jen Christensen, CNN

When Ponce de Leon was searching for the Fountain of Youth in the 16th century, the Spanish explorer should have aimed his boat toward Japan instead of Florida. Okinawa Prefecture has the longest-lived population in the world.

Life expectancy for women in Okinawa is 86; for men. it's 78. That’s 10 years longer than the average life expectancy for men worldwide and 13 years longer than the average life expectancy for women.

Okinawa also has the highest concentration of centenarians in the world. And many remain healthy long into old age.

What’s in the water? The Okinawa Centenarian study, which does a baseline health exam and studies the diet and exercise of over 900 centenarians, notes a few trends.

Okinawans may have won the genetic lottery. They’re at low risk for all the major diseases that tend to kill people, including cancer, heart disease and type 2 diabetes.

Although they are financially poorer than the general Japanese population, Okinawans’ overall quality of life is good.

Vigorous exercise is routine, as is a lean diet. Consequently, their body mass index is low, with an average of 18 to 22. Their diet is rich in green and yellow vegetables, sweet potatoes, soy and fish.

Okinawans typically eat little red meat. They drink in moderation, and few smoke.

Okinawans also tend to stay socially connected. They often live in the same houses as their extended families. Okinawan culture respects the elderly. Centenarians tend to be optimistic, adaptable, independent, creative, calm and easygoing -- all personality traits associated with longevity. Depression and loneliness is minimal.

Doctors think we could learn a lot about healthy aging from Okinawans.

“Low stress, strong family bonds, optimism -- studies show these factors are important, and I’ve noticed this helps with my own patients,” said Dr. Carmel Dyer, director of the Division of Geriatric and Palliative Medicine at the University of Texas' Health Science Center.

Okinawans also tend to work as long as they can, he said.

"We’ve seen when you matter in society, when you think beyond yourself, when you don’t let your brain retire, that’s all very helpful.”

By Sara Cheshire, CNN

Casinos, race cars, luxury yachts and ... healthy babies?

Monte Carlo, in the tiny European country of Monaco, has the world's lowest infant-mortality rate, with an estimated 1.81 deaths per 1,000 live births. That’s mostly because the country's Ministry of Social Affairs and Health reports wide health-care coverage in the city, with a focus on prevention, education and screening.

Quality care during pregnancy, in addition to safe and clean delivery by a skilled attendant and immediate postnatal care, has been shown to prevent infant mortality, according to the World Health Organization.

“Countries like Monaco have high-technology equipment that works and staff highly specialized in working it,” said Vivian Barnekow, Child and Adolescent Health and Development program manager at the WHO’s European office. “In principle, it’s fairly easy to prevent infant mortality if you have the infrastructure for high-quality care.”

The amount of wealth in the country certainly helps. Monaco ranks fifth in the world for highest gross domestic product per capita, the CIA's World Factbook reports.

According to the WHO, children in the poorest 20% of the population in the world are twice as likely to die before their first birthday compared with children in the richest 20%.

“The big thing is that Monaco is a very wealthy city-state,” said Dr. Edward McCabe, senior vice president and chief medical officer at March of Dimes. “We know that prematurity (which is a leading cause of infant mortality) is influenced overall by poverty and lack of access to medical care.”

He says Monaco has three times the physicians per capita as the United States, so access to them isn’t a problem.

“No matter what your ethnicity, if you have full access to health care, your baby is going to have higher probability of being born healthy,” McCabe says.

Fortunately, you don’t have to give birth in the French Riviera to reduce the risk of infant mortality. The CDC recommends that any mother-to-be take folic acid supplements, eat a healthy diet, exercise and get appropriate prenatal care.

By Jacque Wilson, CNN

If you were to get on Interstate 5 near the Mexican border and drive north through Los Angeles, Sacramento, Portland and Seattle, the first stoplight you’d encounter would be in Canada -- just inside Vancouver’s city limits.

That’s because I-5 ends just south of Vancouver, British Columbia, making it the only major city in North America without an interstate running through it, says Deputy City Manager Sadhu Johnston.

With a dense downtown, a strong public transportation system and miles of bike lanes, it’s the “most walkable city in Canada,” Johnston says.

The shift away from a car-centered culture in one reason the city also has some of the cleanest air in the world.

Other reasons include strict environmental standards for buildings and businesses, and a natural environment -- marked by evergreen forests and ocean breezes -- that helps purify air pollutants.

Air quality is a good indicator for health in any city, says Janice Nolen, assistant vice president for national policy at the American Lung Association. “(Pollution) can kill people,” she says. “It can shorten lives by days to months.”

It can cause heart attacks and strokes, asthma in children, low birth weight and, of course, lung cancer.

Car emissions are a major source of these pollutants. Research has showed that people who live close to a busy highway breathe in many more particles and harmful chemicals than those who don’t, Nolen says.

In 2011, Vancouver adopted the Greenest City 2020 Action Plan, which aims to make the Canadian metro area the most environmentally friendly city in the world.

Vancouver’s leaders have done a lot to protect and celebrate its natural environment, Johnston says. Residents have easy access to acres of green space, fresh water, the ocean and nearby mountains.

At the same time, businesses and government have collaborated to build up downtown. As a result, there has been about a 75% increase in the number of people who live and work in Vancouver’s center in the past 20 years, which means fewer commuters driving in and out of the city.

Overall, Vancouver has seen a 6% reduction in its carbon emissions since 1990, Johnston says, despite a nearly 30% growth in population and an 18% growth in jobs. He says the city has showed that “you can create a clean and green environment without impacting your quality of life and your economy.”

By Brandon Griggs, CNN

“Livability” means different things to different people. But Melbourne's quality of life is something most can agree on.

Last month, for the fourth year in a row, this Australian coastal metropolis was named the most livable city in the world by the Economist Intelligence Unit, which researches and ranks places around the globe in a number of categories.

Melbourne topped the 140 cities surveyed by scoring well across a number of criteria, including low crime rates; excellent health care and education; tolerance of different ethnicities, religions and lifestyles; and a bounty of cultural and sporting activities such as tennis’ Australian Open.

All this in a glittering bayside setting with a meandering river, opulent architecture, lots of green space and a temperate climate not unlike San Diego’s.

“The reason Melbourne does so well in our survey is that it presents so few challenges to someone’s daily lifestyle,” says Jon Copestake, a EIU analyst and editor of the annual livability report, which crunches data from the World Bank and other sources.

In other words, the city is clean, safe and welcoming, without the bitter weather, overburdened infrastructure or civil unrest that plague some other urban centers.

Melbourne has an extensive network of rail lines and streetcars, for example, along with a bicycle-sharing system that makes it easy to get around without a car. Considered by many the cultural capital of Australia, it’s also got a thriving arts scene.

But can a city really enhance someone’s mental health? Yes, says Jeff Risom, a partner at Gehl Architects, which designs public spaces that boost wellness. Risom believes that cities with more parks, squares, trains and cultural happenings offer their residents more opportunities for social interaction, which makes them happier.

“We’re social creatures,” he says.

Maybe that’s one reason Melbourne was named the friendliest city on the planet (along with Auckland, New Zealand) last month by readers of Conde Nast Traveler.

The long-term future of this former gold-rush boomtown is less clear. Melbourne is Australia’s fastest-growing city, and runaway growth often brings congestion, crime and other urban ills.

But for now it’s a beautiful, and healthful, place to live.

By Brandon Griggs, CNN

In many respects, New York does not feel like a healthy place. It’s noisy and crowded, and pedestrians court danger every time they step off a curb. Residents must battle the constant stress that comes with sharing a finite urban space with 8 million other people.

But if you’re sensitive to cigarette smoke, it’s a form of paradise. Among big cities, New York has been a steadfast pioneer in cracking down on smoking.

It began nearly two decades ago when the city recognized the hazards of secondhand smoke by passing a law prohibiting smoking in workplaces. In 2002, Mayor Michael Bloomberg extended the smoking ban to include almost all bars and restaurants, sparking an outcry that gradually subsided as most eateries prospered under the new law.

The ban appeared to dampen New Yorkers’ appetite for cigarettes. A survey by the city’s health department found that from 2002 to 2012, the number of adult residents who reported smoking declined by 28%. Over roughly the same period, the smoking rate among New York high school students plummeted by 50%.

Health officials say that even people exposed to low levels of secondhand smoke can develop the same type of lung problems seen in regular smokers. So in 2011, Bloomberg took the anti-tobacco fight outdoors with a bill that made it illegal to smoke in city parks, on beaches and on pedestrian plazas.

“There are very few places left to (legally) smoke,” says Christine Johnson, assistant commissioner for the Bureau of Chronic Disease Prevention and Tobacco Control at the city’s Department of Health and Mental Hygiene. “We want to make it easier for people to quit.”

City leaders also have raised the barriers to buying cigarettes. A law that took effect in May raised the legal age for buying cigarettes and tobacco products from 18 to 21. At the same time, the city hiked the sales tax on tobacco; by law, a pack of cigarettes must sell for at least $10.50, the second-highest price in the nation.

The city’s next public-health cause may be a ban on electronic cigarettes, which are not regulated by the FDA.

“New York has always been a leader in tobacco control,” says Deidre Sully, deputy director of the NYC Coalition for a Smoke-Free City, a program of Public Health Solutions. “One of our main messages is that smoke-free policies are not about villainizing smokers but acknowledging the right of all New Yorkers to breathe clean, smoke-free air.”

By Paul Frysh, CNN

The number of people reaching the age of 65 will increase exponentially in the Western world over the next couple of decades. Governments will need systems that not only provide good quality care for the elderly but that are sustainable long-term.

Leaders could learn a lot by making the trip to the city of Jonkoping in southern Sweden and asking, "What's good for Esther?"

Esther is a reasonably self-sufficient elderly pensioner with some chronic health issues. She has friends in the area and a daughter in the town next to Jonkoping but spends an increasing amount of time alone in her small apartment.

Esther is 88 years old. She always has been and always will be.

That's because Esther is an imaginary person dreamed up by a group of government administrators to help them think through problems in the life of the elderly. The result became known as the Esther Project.

Sweden ranks near the top on quality of life for the elderly by many measures, says Andrew Scharlach, professor of aging at the University of California School of Social Welfare, including income security, life expectancy, psychological well-being, employment and education.

It is a good system, says Goran Henriks, chief executive of learning and innovation for Jonkoping. But there’s always room for improvement.

When Henriks and his team asked what would happen if Esther called her daughter complaining of chest pains, they found that Esther was shuffled from place to place for 12 hours, subjected to redundant tests and long waits and asked nearly identical questions by as many as 30 people.

Asking "What's good for Esther?" led to new policy, says Henriks, that would have Esther attended to by a local nurse and resting at home for a few days before going to the hospital for an outpatient procedure -- far less taxing both on the system and on Esther.

Over the long term, Henriks says, the Esther Project has resulted in a uniquely streamlined and integrated program of care for the elderly in Jonkoping that has been very successful, sometimes in surprising ways. One unexpected result was a big reduction in the need for hospital beds in the region, which was a huge cost savings for the area.

Esther now has ageless siblings throughout the country, says Henriks: Kersti, Helga, Nisse, Linnea, Herman, Britta -- all helping to improve life for the elderly in Sweden.

By Matt Sloane, CNN

It may seem unlikely, but Havana, Cuba, is one of the healthiest cities on the planet.

Yes, much of the country is in abject poverty, and the trade embargo by the United States has kept some of the best medical technologies out of health care workers’ hands. But a focus on prevention has helped many residents avoid the hospital altogether.

Consider these facts: Cuba, a country with 11 million people, has an average life expectancy of 79 years, the same as the life expectancy in the United States. The infant mortality rate is actually better than in America. And the Cuban government spends an average of just $400 per person on health care; the United States spends close to $9,000.

How? One word: prevention.

“Fundamentally, prevention is how you keep your costs down,” says Pierre LaRamee, the executive director of MEDICC, a nonprofit cooperative medical effort between the United States and Cuba. “If you’re a country with very limited resources like Cuba, you put all of your resources into the most effective, most low-cost interventions.”

Simple things like a near-100% vaccination rate and regular health screenings help. Every community has a network of small doctors' offices in nearby homes and free access to neighborhood “polyclinics.”

Larger tertiary care hospitals are reserved for the most complicated cases, and problems that can be headed off early in the small clinics are dealt with locally.

Taking care of yourself and your neighbors is a practice that everyone is taught from a young age in Havana, says LaRamee. Kids are taught basic first aid and CPR, which is important in an area that’s often in the path of many hurricanes and where emergency medical services are scarce.

“If people are trained early on to think about their overall health – the need for proper nutrition, the need for exercise – that creates a culture of health," LaRamee says.

Another effect of the government's focus on preventive care: Medical school is free, and Cuba trains more doctors than any other Latin American country.

Some critics point out that doctors make between $20 and $30 per month, about the same as everyone else, and are often forced to take side jobs as taxi drivers to earn extra money. Treatment for more complicated or rare diseases is often nonexistent and 25% of the adult male population still smokes.

All of that said, Havana is a prime example of what public health officials in America have been saying for a long time: It's better to prevent the problem in the first place than to have to treat it.

By Sara Cheshire, CNN

If you’re going to get sick, Singapore is the place to do it.

Ranked as one of the most efficient systems on the planet, the city-state's public health-care program is used by 80% of residents.

More important, Singapore spends less on health care than any other wealthy country in the world. In 2013, 4.7% of its gross domestic product went to health; the United States spent 17.9%, according to the World Bank.

So what’s its secret? The Ministry of Health requires all citizens to participate in a health savings program called Medisave, which ensures that they have enough put aside to cover future expenses. Residents also receive health care subsidies based on income level. Medical costs must be clearly presented, and the government controls insurance companies.

“Price and outcome transparency are very important to quality,” said William Haseltine, chairman and president of ACCESS Health International Inc. and a former professor at Harvard Medical School and the Harvard School of Public Health. “Without it, it is very difficult to manage a health care system.”

In his book, “Affordable Excellence: The Singapore Healthcare Story,” Haseltine says that Singapore understood early on the need to integrate health with every aspect of urban planning. Housing, water, food, air quality, road traffic, parks and more were considered to be part of a holistic health system.

Paying attention to social and environmental conditions such as these is a hallmark of successful health care systems, says Kisha B. Holden, associate professor of psychiatry and behavioral sciences at the Morehouse School of Medicine, who specializes in health disparities.

Quality health programs pay attention to the needs of the people being served, she says. They have attractive financial systems, provide community education and focus on preventive care -- all of which Singapore does.

Haseltine says some of Singapore’s more successful health campaigns have included rental bicycle, trans fat-free and anti-smoking programs. There’s also an entire government agency, the Health Promotion Board, dedicated to promoting healthy diets, exercise, health education and regular screenings.

“They have developed a very high-quality health care system that provides uniform care regardless of income,” Haseltine said.

He believes the principles that make the Singapore health system work so well can also be applied in other places.

“It is important to look at what can be done. High-quality health care can be delivered at the fraction of the cost.”

By Jacque Wilson, CNN

When we asked users of iReport, CNN’s user-generated news community, to show us how their cities inspire healthy habits, hundreds of people jumped into action.

There was dancing in San Diego and Montreal, water skiing in Birmingham, Alabama, and plyometrics in Munich, Germany.

But it was the residents of Napa, California, who really hit the ground running.

“Napa has an abundance of healthy things,” raves Remi Cohen, leader of the World Beat Dance Collective, a local group. In addition to locally grown food and hiking and biking trails, she says, the city supports “an amazing arts culture.”

“Our goal is for the healthy choice to be the easy choice by making it accessible,” says Cara Mae Wooledge, a health education specialist with the Napa County Health and Human Services Agency's Public Health Division. Wooledge encouraged residents in Napa to submit more than 50 videos for the iReport challenge.

Let’s be honest: Napa is best known for its wine. The list of vineyard tours and wine tastings in its famous valley is enough to make your head swim -- sans alcohol.

Though new research shows the antioxidant in red wine won’t necessarily help you live longer, having a glass or two certainly can’t hurt -- and may even provide some much-needed stress relief. Plus there are other health benefits to living in Napa, the city’s residents say.

Members of the Obesity Prevention Coalition bike to the group’s meetings. Queen of the Valley Medical Center teaches nutritional cooking classes in both English and Spanish. A Breastfeeding Coalition encourages new mothers to breastfeed their babies. There’s even a hula-hooping group, the Napa Hoopers, led by hula-hoop pro Lilea Duran.

Duran says the city has a small-town feel. The community comes together for social events on holidays, and neighbors stop by to offer extra zucchini from their gardens.

“Napa County is a place that isn't afraid to have fun,” says Duran. “We are a place that knows not just where our food comes from but ... the farmer that grew it, too.”