【正文】 se who slept 7. It’s well known that obesity impairs sleep, so perhaps people get fat first and sleep less afterwards. But the nurses’ study suggests that it can work in the other direction too: sleep loss may precipitate weight gain. Although getting figures is difficult, it appears that we really are sleeping less. In 1960 people in the US slept an average of hours per night. A 2022 poll by the National Sleep Foundation suggests that the average has fallen to under 7 hours, and the decline is mirrored by the increase in obesity. 2. Climate control We humans, like all warmblooded animals, can keep our core body temperatures pretty much constant regardless of what’s going on in the world around us. We do this by altering our metabolic(新陳代謝的 ) rate, shivering or sweating. Keeping warm and staying cool take energy unless we are in the “thermoneutral zone”, which is increasingly where we choose to live and work. There is no denying that ambient temperatures(環(huán)境溫度 ) have changed in the past few decades. Between 1970 and 2022, the average British home warmed from a chilly 13C to 18C. In the US, the changes have been at the other end of the thermometer as the proportion of homes with air conditionings rose from 23% to 47% between 1978 and 1997. In the southern states – where obesity rates tend to be highest – the number of houses with air conditioning has shot up to 71% from 37% in 1978. Could air conditioning in summer and heating in winter really make a difference to our weight? Sadly, there is some evidence that it doesat least with regard to heating. Studies show that in fortable temperatures we use less energy. smoking Bad news: smokers really do tend to be thinner than the rest of us, and quitting really does pack on the pounds, though no one is sure why. It probably has something to do with the fact that nicotine(尼古丁 )is an appetite suppressant and appears to up your metabolic rate. Katherine Flegal and colleagues at the US National Center for Health Statistics in Hyattsville, Maryland, have calculated that people kicking the habit have been responsible for a small but significant portion of the US epidemic of fatness. From data collected around 1991 by the US National Health and Nutrition Examination Survey, hey worked out that people who had quit in the previous decade were much more likely to be overweight than smokers and people who had never smoked. Among men, for example, nearly half of quitters were overweight pared with 37% of nonsmokers and only 28%of smokers. 4. Geic effects Yours chances of being fat may be set, at least in part, before you were even born. Children of obese mothers are much more likely to bee obese themselves later in life. Offspring of mice fed a highfat diet during pregnancy are much more likely to bee fat than the offspring of identical mice fed a normal diet. Intriguingly, the effect persists for two or three generations. Grandchildren of mice fed a highfat diet grow up fat even if their own mother is fed normallyso you fate may have been sealed even before you were conceived. little older… Some groups of people just happen to be fatter than others. Surveys carried out by the US national center for health Statistics found that adults aged 40 to 79 were around three times as likely to be obese as younger people. Nonwhite females also tend to fall at the fatter end of the spectrum: MexicanAmerican women are 30% more likely than white women to be obsess, and black women have twice the risk. In the US, these groups account for an increasing percentage of the population. Between 1970 and 2022 the US population aged 35 to 44 grew by 43%. The proportion of HispanicAmericans also grew, from under 5% to % of the population, while the proportion of black Americans increased from 11% to %.these changes may account in part for the increased prevalence of obesity. mums Mothers around the world are getting older. In the UK, the mean age for having a first child is , pared with in 1970. Mean age at first birth in the US has also increased, rising from in 1970 to in 2022. This would be neither here nor there if it weren’t for the observation that having an older mother seems to be an independent risk factor for obesity. Results from the US national heart, lung and blood institute’s study found that the odds of a child being obese increase 14% for every five extra years of their mother’s age , though why this should be so is not entirely clear. Michael Symonds at the university of Nottingham, UK, found that firstborn children have more fat than younger ones. As family size decreases, firstborns account for a greater share of the population. In 1964, British women gave birth to an average of children。 by 2022 that figure had fallen to . In the US in 1976, % of woman in their 40s had only one child。 his MBA thesis was on marketing athletic shoes. Once he received his degree, Knight traveled to Japan to contact the Onitsuka Tiger Company, a manufacturer of athletic shoes. Knight convinced the pany’s officials of the potential for its product in the . In 1963 he received his first shipment of Tiger shoes, 200 pairs in total. In 1964, Knight and Bowerman contributed $500 each to from Blue Ribbon Sports, the predecessor of Nike. In the first few years, Knight distributed shoes out of his car at local track meets. The first employees hired by Knight were former college athletes. The pany did not have the money to hire “experts”, and there was no established athletic footwear industry in North America from which to recruit those knowledgeable in the field. In its early years the anization operated in an unconventional manner that characterized its innovative and entrepreneurial approach to the industry. Communication was informal。 those things happen pretty much on their own, but as arguments about immigration hear