The new reality is captured by a single, stark fact: Across the world, more people are now obese than underweight. At the same time, scientists say, the growing availability of high-calorie, nutrient-poor foods is generating a new type of malnutrition, one in which a growing number of people are both overweight and undernourished ... The prevalence of obesity has doubled in 73 countries since 1980, contributing to four million premature deaths

But according to a recent report by the National Center for Education Statistics, only a fraction of high schools are starting later than 8:30 a.m., which is what the American Academy of Pediatrics recommends.[U.S. doctors urge later school start times for teens]The average start time for high schools in the United States is 7:59 a.m., according to the report, published Tuesday. For middle and elementary schools, it’s a little later: 8:04 a.m. and 8:17 a.m.

By 2000, only 5,970 cases were reported in the United States, the lowest since 1941... But in the last few years, it has crept back.... Syphilis is devilishly difficult to contain, but may be even more so now. Because most doctors haven’t seen a case since the late 1990s, they often misdiagnose it. The cumbersome two-step lab test is antiquated. Although syphilis can be cured with an injection, there has been a shortage of the antibiotic, made only by Pfizer, for over a year.

American women are more than three times as likely as Canadian women to die in the maternal period...six times as likely to die as Scandinavians. In every other wealthy country, and many less affluent ones, maternal mortality rates have been falling... But in the U.S., maternal deaths increased from 2000 to 2014. In a recent analysis by the CDC Foundation, nearly 60 percent of such deaths were preventable.

Climate change is melting permafrost soils that have been frozen for thousands of years, and as the soils melt they are releasing ancient viruses and bacteria that, having lain dormant, are springing back to life ... The temperature in the Arctic Circle is rising quickly, about three times faster than in the rest of the world ... Frozen permafrost soil is the perfect place for bacteria to remain alive for very long periods of time, perhaps as long as a million years.

Brownsville, more than Miami, that highlights the ways in which Zika may take hold in the United States now, because in Brownsville, every factor that might encourage Zika already exists. The weather is semitropical and humid ... Its residents have high rates of obesity and diabetes, conditions that undermine the body’s defenses against disease. It is one of the poorest cities in the country, and the housing is frequently substandard ... the city contains an untraceable churn of people.

a year after Berkeley’s soda tax took effect in 2015, the city saw a nearly 10 percent drop in purchases of sugary drinks and a nearly 16 percent increase in sales of bottled water ... Last year, voters approved a similar soda tax in San Francisco, Oakland and Albany, Calif., as well as in Boulder, Colo., Cook County, Ill., and Philadelphia. Santa Fe, N.M., and Seattle are considering soda taxes.

From 2013 to 2014, Maine saw the third-highest increase in any state, 27 percent ... Twenty years ago, just 34 people died from drug overdoses ... Only four years ago, there were 176 overdose deaths, less than half the 2016 total ... The death toll reached 378 in 2016, driven almost entirely by opioids – prescription painkillers, heroin and now fentanyl, a powerful synthetic. More than one victim per day. More than car accidents. Or suicide. Or breast cancer.

New data released by Yale researchers gives the most detailed view yet of public opinion on global warming. In Florida, the effects of climate change, including sunny-day flooding, are being felt across the state. Four southeast Florida counties — Miami-Dade, Broward, and Monroe and Palm Beach — stand out because of their concerted effort to work on climate issues together and to discuss it in nonpartisan terms.

In early 2001, the mayor of Paris...integrated a bikeshare program: a system where people could rent bikes and ride them between a network of stations throughout the city. Though it wasn’t the first such effort in history, it was the catalyst for an international bikesharing revolution. In the past decade, more than 600 cities around the world have implemented similar plans, collectively deploying more than 700,000 bicycles.