In last week’s column, we took a look at chronic illness, one of the five major worldwide problems cited in Daniel Callahan’s book, “The Five Horsemen of the Modern World,” featuring everything you need to know about climate, food and water shortages, chronic illness, and obesity.

This week I’ll tell you a bit about the problems of food, water shortages, and obesity. Let’s start with that. Callahan reports, “In the United States some 67 percent of Americans are overweight or obese, with 35 percent obese. American children are little better off: 18 percent of children ages 6 to 11 are obese, and for those ages 12 to 19, the figure is 21 percent.”

And this is a worldwide problem. “Globally,” reports Callahan, “35 percent of adults age 20 or older were overweight in 2008, and 11 percent were obese. Worldwide obesity rates have doubled since 2008.”

Perhaps you don’t consider this a significant problem. “Save for a few countries and regions,” Callahan notes, “the global impact of obesity is socially pervasive, dangerously unhealthy, economically burdensome, and in many places a source of occupational and medical discrimination.”

I’m not saying this is the solution for our country, but in Japan, overweight citizens are required to go to dieting classes. And Japan is a country featuring a good diet and the lowest rate of obesity in the world!

Hungary enacted a “fat tax” in 2011 on foods with high fat, sugar and salt content, and increased tariffs on sugar-sweetened beverages and alcohol. Finland and Denmark are also moving in that direction. And while research is central to solving the other four horsemen, Callahan notes that food research is often aimed at finding ways of luring us to unhealthy foods, especially sugar.

Somewhat ironically, food shortages are another major worldwide problem, with population growth rates increasing much faster than food production. Eight-hundred million people around the world are hungry. “While malnutrition is not the only source of trouble for those living in the poorest countries,” reports Callahan, “it is a major part: they are the most directly harmed by food shortages. Their populations spend 70 to 80 percent of their income on food, compared with 10 percent for those in industrialized countries.” Children in those countries have a high mortality rate, with about 54 percent of their deaths associated with malnutrition.

Global warming is going to make this awful problem even worse, predicted to reduce food production by 2 percent each decade, while the demand for food increases by 14 percent each decade. Between 1990 and 2005 the amount of farmed area increased by 1.8 percent while the population increased 23 percent. And the costs of food production have risen sharply, with a doubling of energy costs for fuel and fertilizers for farmers exporting food from the United States.

One of my pet peeves is the use of food (corn) to produce fuel (ethanol). Adding ethanol to our gasoline has not only harmed small engines. “By 2006,” writes Callahan, “40 percent of the U.S. corn crop was devoted to ethanol production, yet it replaced only 3 percent of fossil fuel consumption.”

Solutions to food shortages are complex and far from certain. Essentially, we must figure out how to produce more with less. Callahan cites the need for global agricultural productivity improvement, reducing agricultural protectionism, managing national interfaces with unstable world markets, and national and international food safety nets.

I’ve written about the worldwide shortage of water before. As Callahan reports, “One billion people lack safe drinking water, and 2 million people die annually of diarrheal disease from unsafe water. Cholera is reportedly found in 50 countries, in great part transmitted by dirty water.”

He uses an example that is familiar to me: the 2,000-mile Rio Grande River.

On our first visit to Big Bend National Park in southwest Texas, which borders the Rio Grande, I asked why there was so little water in the river, and was told that every bit of the river’s water was used in the United States, before the river passes into Mexico, so all the water I was seeing came from Mexican sources.

In some sections of India, young girls are not able to go to school because they spend all day walking to collect and bring water back to their families.

Callahan does offer some hope that the water crisis can be solved, offering 25 solutions, including reducing water wastage, educating consumers and farmers about water-saving practices, pricing water based on its true cost, monitoring all water extraction and penalizing illegal extraction, ending government subsidies, improving water efficiency on farms, reducing leaks in infrastructure, recycling all urban water, and investing more in water science and technology.

Next week we’ll examine the fifth horseman, climate change, which may make all the other horsemen irrelevant.

George Smith is a writer and TV talk show host. He can be reached at 34 Blake Hill Road, Mount Vernon 04352, or georgesmithmaine@gmail.com. Read more of Smith’s writings at www.georgesmithmaine.com.