We've reached a strange—some would say unusual—point. While fighting world hunger continues to be the matter of vital importance according to a recent report from the World Health Organization (WHO), more people now die from being overweight, or say, from being extremely fat, than from being underweight. It's the good life that's more likely to kill us these days.

Worse, nearly 18 million children under the age of five around the world are estimated to be overweight. What's going on?

    We really don't have many excuses for our weight problems. The dangers of the problem have been drilled into us by public ­health campaigns since 2001 and the message is getting through—up to a point.

    In the 1970s, Finland, for example, had the highest rate of heart disease in the world and being overweight was its main cause. Not any more. A public ­health campaign has greatly reduced the number of heart disease deaths by 80 per cent over the past three decades.

    Maybe that explains why the percentage of people in Finland taking diet pills doubled between 2001 and 2005, and doctors even offer surgery of removing fat inside and change the shape of the body. That has become a sort of fashion. No wonder it ranks as the world's most body ­conscious country.

We know what we should be doing to lose weight—but actually doing it is another matter. By far the most popular excuse is not taking enough exercise. More than half of us admit we lack willpower.

    Others blame good food. They say: it's just too inviting and it makes them overeat. Still others lay the blame on the Americans, complaining that pounds have piled on thanks to eating too much American­ style fast food.

    Some also blame their parents—their genes. But unfortunately, the parents are wronged because they're normal in shape, or rather slim.

    It's a similar story around the world, although people are relatively unlikely to have tried to lose weight. Parents are eager to see their kids shape up. Do as I say—not as I do.

    As an expert on the science of sleep and sleep disorders, Michael Twery believes “People have good understanding about the necessity of sleeping 7-8 hours in bed. But they undervalue the function of napping in day.”

    For example, many Americans do nap. But one-third of adults in the US are also frequently tired. Someone who naps as a way of paying off a sleep debt may not experience the same improvements from napping as a healthy, well-rested person would.

    Also, many people may not want to admit that they take a nap. That only children, the very old, sick or lazy people nap is a common opinion. In fact, Americans sometimes do very strange things. For those who claim they only sleep five hours a night, they may think they are somehow stronger than the average human—superhuman, if you will.

    Luckily, many offices now offer napping rooms in many U. S. cities. While resting in the middle of the work day may seem like a luxury to Americans, napping is very much part of a normal, everyday life in other parts of the world.

China, generally speaking, is a land of nappers. Researchers recently looked at information provided by nearly 3, 000 Chinese adults, aged 65 years or older. Based on their answers, researchers put them into four groups: non-nappers (0 minutes), short nappers (less than 30 minutes), moderate nappers (30-90minutes), and extended nappers (more than 90 minutes).

    The study found that the hour-long nappers did better on the tests than those who napped for shorter and longer periods. Keep in mind, however, that these are the findings for those over the age of 65.

    Michael Twery notes that an hour long nap may be too long for young, healthy adults. “Currently, 30 minutes is enough to remove the pressure to sleep and will help us feel more awake. If we nap longer, we will get trapped into sleep inertia—a very deep sleep period.”

    Philadelphia, Pennsylvania w America's fifth largest city. Once a major American colonial city, it is the home of America's first library, its first hospital, and its first zoo. Now it is also the first US city to be named a World Heritage City. On November 6, 2015. Philadelphia joined more than 260 other cities that have been recognized for their influence on the world. These cities include Paris, France Florence, Italy and Cairo Egypt.

    "Today marks the start of a new and exciting chapter in the history of Philadelphia" remarked Philadelphia Mayor Michael Nutter when the announcement was made. “As a World Heritage City. Philadelphia is being officially recognized on the global stage for its wealth of contributions to the world. ”

    To be named a World Heritage City, a city be home to a UNESCO World Heritage site are selected for their universal value and significance. For Philadelphia, the site is Independence Hall.

    Independence Hall is where two of the most important documents, approved in US history - the Declaration of Independence and the US Constitution-were adopted. The Declaration of Independence, approved on July 4 1776, united the 13 former British colonies and declared them independent from British rule. The US constitution, signed in 1787, established the American democratic system of government. Democracy is a system of government in which the people elect their leaders. The Constitution later spelled out basic freedoms American citizens have.

    Philadelphia Deputy Mayor Alan Greenberger says the city's selection as a World Heritage City also reflects ta its educational, cultural, and economic achievements. The city is home to dozens of colleges and universities, and many museums, such as the Philadelphia Museum of Art.“Philadelphia has rightfully earned its place as one of the greatest cities in the world.” Greenberger says.

    Benjamin West, the father of American painting, showed his talent for art when he was only six years of age. But he did not know about brushes before a visitor told him he needed one. In those days, a brush was made from camel's hair. There were no camels nearby. Benjamin decided that cat hair would work instead. He cut some fur from the family cat to make a brush.

    The brush did not last long. Soon Benjamin needed more fur. Before long, the cat began to look ragged（蓬乱）. His father said that the cat must be sick. Benjamin was forced to admit what he had been doing.

    The cat's lot was about to improve. That year, one of Benjamin's cousins, Mr. Pennington, came to visit. He was impressed with Benjamin's drawings. When he went home, he sent Benjamin a box of paint and some brushes. He also sent six engravings（版画） by an artist. These were the first pictures and first real paint and brushes Benjamin had ever seen. In 1747, when Benjamin was nine years old, Mr. Pennington returned for another visit. He was amazed at what Benjamin had done with his gift. He asked Benjamin's parents if he might take the boy to Philadelphia for a visit.

    In the city, Mr. Pennington gave Benjamin materials for creating oil paintings. The boy began a landscape(风景) painting. William Williams, a well-known painter, came to see him work. Williams was impressed with Benjamin and gave him two classic books on painting to take home. The books were long and dull. Benjamin could read only a little, having been a poor student. But he later said,＂ Those two books were my companions by day, and under my pillow at night.＂ While it is likely that he understood very little of the books, they were his introduction to classical paintings. The nine-year-old boy decided then that he would be an artist.

    Here is an astonishing and significant fact: Mental work alone can't make us tired. It sounds absurd. But a few years ago, scientists tried to find out how long the human brain could labor without reaching a stage of fatigue(疲劳). To the amazement of these scientists, they discovered that blood passing through the brain, when it is active, shows no fatigue at all! If we took a drop of blood from a day laborer, we would find it full of fatigue toxins(毒素)and fatigue products. But if we took blood from the brain of an Albert Einstein, it would show no fatigue toxins at the end of the day.

    So far as the brain is concerned, it can work as well and swiftly at the end of eight or even twelve hours of effort as at the beginning. The brain is totally tireless. So what makes us tired?

    Some scientists declare that most of our fatigue comes from our mental and emotional(情感的)attitudes. One of England's most outstanding scientists, J. A. Hadfield, says, "The greater part of the fatigue from which we suffer is of mental origin. In fact, fatigue of purely physical origin is rare. "Dr. Brill, a famous American scientist, goes even further. He declares, "One hundred percent of the fatigue of a sitting worker in good health is due to emotional problems. "

    What kinds of emotions make sitting workers tired? Joy? Satisfaction? No! A feeling of being bored, anger, anxiety, tenseness, worry, a feeling of not being appreciated—those are the emotions that tire sitting workers. Hard work by itself seldom causes fatigue. We get tired because our emotions produce nervousness in the body.

The Secret to Happiness

    A new report makes it clear that when it comes to the life satisfaction of UK citizens, the ball is in the government's court. For some time, sensible people have been arguing that governments need to focus less on economic growth and more on the wellbeing（幸福）of citizens. Be careful what you wish for.

    In response to this demand, from 2011 David Cameron instructed the Office for National Statistics to gather data on people's self-reported happiness and life satisfaction. Little practical good has come from this so far, but a new report by George Bangham for the Resolution Foundation is one of the best attempts to make useful sense of the data. He concludes: "The best prospects for policymakers targeting future increases in national wellbeing lie in raising job quality, raising incomes, particularly at the lower end, and policies to improve security in the housing market."

    The age correlation（相关）turns out to be certainly linked to politics, despite the fact that no political party can make a difference to your date of birth. The happiness of pensioners is not just a function of their age, but of policy. On average, 70-year-old boomers today are the most affluent retirees in history, often owning their own homes and in receipt of generous pensions. People of 70 are not going to be as content in 30 or 40 years' time if they are unable to retire, don't own their homes and have small incomes.

    However, there is one respect in which teens and recent retirees are remarkably similar. Compared to other age groups, they tend to inhabit a sweet spot of having high degrees of freedom. The typical 16-year-old has new freedoms without ever having had any serious responsibilities. The typical 70-year-old, having experienced a lifetime of work and family duties, has a very different kind of freedom, one born from relief.

    Besides, it should not surprise us to find that people tend to be happier when they have fewer worries. But this, too, has important political implications. If the government is really interested in raising overall national happiness, it has to make sure as many citizens as possible feel secure in their health, their housing and their incomes. Different states' records in achieving this is one important reason why Nordic countries repeatedly score highly in international life satisfaction surveys and North America underperforms relative to its GDP.

    Whichever way you look at it, there is no escaping the conclusion that increasing wellbeing across society requires joined-up, long-term policy efforts. This is exactly what the Resolution Foundation recommends.