Obesity has become one of the greatest health scourges of our time. Around the world, it contributes to three million deaths each year. There are more than a billion adults who classify as overweight or obese, and the epidemic has hit developing countries, where starvation and malnutrition are still widespread. As researchers learn more about the social and economic impact of obesity, a number of basic unanswered questions remain — such as why obesity rates have soared in the last three decades, and how to turn that trend around. Here are 21 maps and charts that explain what we know about obesity.
Obesity is a medical term for carrying too much fat
The word obesity comes from the Latin "obesitas," meaning fat or plump. "Body mass index" or BMI — a calculation of a person’s height and weight — is the most widely used method for measuring obesity, though it is by no means perfect. BMI will put really muscular folks — and some actors such as Tom Cruise — in the overweight and obese categories because it cannot distinguish between lean muscle mass and fat mass. For most people, however, it's a good indicator. You can find your BMI using this online calculator or on the chart here. A BMI of 25 or more puts a person in the overweight category; 30 is the threshold for obesity.
What obesity looks like (and why waist size matters)
You can see BMI visualized by watching this figure grow from a normal body weight to overweight and then obese. You’ll notice the waistline here puff up; that excess fat around the midline is another important measure of obesity that’s not reflected in BMI. Larger waists are associated with an increased risk of type-2 diabetes, cardiovascular disease and death, even after controlling for BMI. You can easily tell whether your waist size puts you in the danger zone: abdominal obesity in women is a waist size that’s 35 inches or more, and in men, it’s 40 inches or more.
People are really bad judges of their own overweightness
In a recent study, researchers at the Rush University Medical Center in Chicago set out to see how African American women thought about their body weight. They used this "body image scale" to determine what women deemed normal weight, overweight, and obese. "Overweight figures were not considered too fat," the researchers found. So even though the women in pictures 2, 3, and 4 are normal weight —and all the other figures are overweight and obese, the participants in the study only thought the last two drawings (8 and 9 ) were tipping the scales. White women, on the other hand, tend to place themselves in a higher weight group than they actually are.
Americans have only gotten fatter over time
This data from the Centers for Disease Control and Prevention shows the red tide of obesity spreading across the United States over the last 30 years. Between 1980 and 2000, obesity rates doubled among adults: 30 percent of the adult population is now obese. In the same period, obesity rates doubled among children and tripled among adults. The scary part is that, despite the clear and dramatic increase in obesity rates, no one has been able to figure out exactly what’s driving this trend. As the Centers for Disease Control and Prevention researcher Katherine Flegal put it, "There’s a lot of speculation, but we don’t really know the answer."
In every state, at least one-fifth of adults are obese
In the Southern and Midwestern parts of the country, the problem is even more acute, and Mississippi and West Virginia have the highest obesity rates in the country at over 35 percent. Only seven states — Massachusetts, Hawaii, Colorado, Vermont, Montana, Utah, California — and the District of Columbia have obesity rates below a quarter. Colorado was the least obese state, with a prevalence of 21.3 percent, followed by Hawaii at 21.8 percent.
Obesity is less common among white people compared to other races
Black people reported the highest obesity prevalence (37.6 percent) followed by Hispanic people (30.6 percent) and then white people (26.6 percent). So there was more than a 10 percentage point difference between obesity in blacks and whites. This map shows the obesity prevalence by state among white people for the years 2011 to 2013.
Obesity is most prevalent among African Americans
By contrast, this map shows obesity rates among black adults for the same years. There are many more states reporting the highest level of obesity for this population. According to the CDC, nearly 40 percent of black men 20 years of age and older are obese. No population in the US has an obesity rate as high as black adult women: 58 percent are obese.
Less educated and poorer people are more obese
The Robert Wood Johnson Foundation's State of Obesity study found a strong correlation between obesity, and education and income levels. Of adults who didn’t graduate high school, over 35 percent were obese compared with 26 percent of those who finished college. Meanwhile, 33 percent of adults who earn less than $15,000 per year were obese, while a quarter of those who earned at least $50,000 were obese.
Obesity is not a uniquely American phenomenon
Worldwide, obesity has nearly doubled since 1980. People are fatter now everywhere, even in the poorest developing countries, where malnutrition and starvation are widespread problems. In 2008, more than 1.4 billion adults were overweight. Of those, over 500 million men and women were obese. The trend now reaches into the southern hemisphere. Obesity is a problem in Mexico, the Middle East, and in several countries in Africa.
Excess weight takes years off your life
"Excess weight, especially obesity, diminishes almost every aspect of health," according to the Harvard School of Public Health, "from reproductive and respiratory function to memory and mood." Being obese raises one’s risk of death from a range of diseases including diabetes, high blood pressure, stroke, heart disease, asthma, infertility, sleep apnea, kidney stones, and several types of cancer. Obesity is also associated with shorter lifespans and, the higher one’s BMI, the more years of life lost. For example, a 20-year-old man with a BMI of 40 will live six years less than a non-obese man the same age.
Obesity is associated with lower wages, especially for women
Researchers at George Washington University tried to quantify the economic impact of obesity on men and women. They found that obesity is associated with almost twice the cost for women as compared to men. As well, 38 percent of this cost for women came from lower wages, while the incomes of obese men barely suffered. "This [gender] disparity around wages represents the stigmatization and discrimination against obese individuals, and particularly Caucasian females," said William Dietz of the Centers for Disease Control and Prevention. "This stigmatization is pervasive and longstanding." The study also showed that incremental increases in weight were linked to increases in personal cost. So every extra pound cost study participants more. Still, it’s not clear what comes first: obesity or the low-paying jobs.
Obesity costs the US a lot
Nearly ten percent of health-care spending goes to obesity each year in the US. In 2008, obesity-related costs totaled about $147 billion. That’s because, compared with normal weight people, obese patients have been estimated to spend 46 percent more on hospital visits, 27 percent more on doctor exams, and 80 percent more on prescription drugs.
The most basic explanation for how we got so fat
No one knows exactly why so many people got so fat in recent decades. But the most straightforward explanation for the rising rates of overweight and obesity is that food production increased, food became cheaper than it ever was, and so people started eating more calories. The average American’s total calorie intake grew from 2,109 calories in 1970 to 2,568 calories in 2010. As Pew Research put it, that’s "the equivalent of an extra steak sandwich every day." And a lack of energy balance — more calories in than we expend — is the simplest of explanation for obesity.
We’re walking less, driving more
One study, featured in the Economist, showed that there is a striking correlation between rising obesity and the rising popularity of driving. The implication here is that the more we use cars to get around, the less we use our bodies to do so, and the fewer calories we burn off. According to the CDC, less than half of all adults now meet the Physical Activity Guidelines.
Fruit and vegetables make up a small part of the American diet
Relative to grains, meat, dairy and fat, Americans eat few fruits and vegetables. On average, people in the US now eat about 250 to 300 grams of carbs a day, which makes up more than half of their caloric intake. Obesity experts agree that in order to maintain a healthy weight, half of every meal should come from plants, and yet plants make up a small proportion of the American diet while intake of energy-dense carbs has been on the rise.
We’re eating out more
More than half of our food dollars are being spent on restaurant foods and processed, convenient, on-the-go meals. You’re much more likely to pack on calories when you eat out. Compared to home-cooked meals, breakfasts at sit-down restaurants typically have 261 more calories, lunches have 183 more calories, and dinners have 219 more calories. That’s about 600 extra calories per day.
We’re consuming more added sugar
Added sugars — the sweeteners in processed foods like cakes and sugary beverages — make up an increasingly large part of the American diet. Women should have no more than six teaspoons of sugar per day, and men no more than nine teaspoons. Yet the Center for Science in the Public Interest reported that the average American is now consuming 23 teaspoons of added sugar each day. While consuming so much extra sugar is a compelling explanation for the surge in obesity rates, what’s really driving the trend is probably a mixture of all of the above.
There is no "best diet" for losing weight
How do we reverse the trend? Unfortunately, there truly is no magic diet, no weight loss wonder, or thinning superfood. A number of high-quality studies have found that all diets work about the same. For example, a randomized trial involving 300 women on Atkins (very low in carbohydrates), Zone (low carb), Ornish (very high carb), and LEARN (low in fat, high in carb, based on U.S. guidelines) diets found that, while women on Atkins lost a little more, weight loss with a low-carb diet is "likely to be at least as large as for any other dietary pattern."
There's one thing you need to know about diet and weight loss
It’s rather straightforward: what will work is cutting calories in a way that you like and can sustain. Dr. Yoni Freedhoff, an Ottawa-based obesity doctor, says he tells people, "Ultimately you need to like the life you're living food-wise if you're going to keep living that way. It's crazy to think, with billions of people on the planet, that there's one approach that suits everybody." He added: "The best diet for one individual is the worst diet for another individual."
Obesity-fighting policies might help
Instead of leaving weight control up to individuals, proponents of obesity-fighting policies believe we need to re-engineer our environments to nudge people to make healthier choices. These policy experiments are being tried all over the world. Voters in Berkeley, California just introduced the first tax on sugary-beverages in the nation, which will add 1¢ per ounce to drinks with added sugar. Mexico put a soda tax in place in 2013. While these taxes have sometimes changed consumption habits, they haven't yet succeeded in reducing obesity rates. But in the face of a public-health problem of epidemic proportions, proponents say trying out policies that encourage healthy behavior is important.
Obesity rates have stabilized in recent years
There is some good news on obesity: the surge in obesity rates in the US and around the world appears to have decelerated in recent years. This chart shows the prevalence of overweight and obesity over time in men and women in developing and developed countries between 1980 and 2013. The surge between 1992 and 2002 slows, especially in the developed world in the last decade. Exactly why this has occurred remains a scientific mystery, but researchers think it's the impact of some combination of changes in policy, increased awareness about healthy lifestyles, and the attention that has been paid to stopping obesity in early childhood.
The shape we’re in
The cost of obesity
How did we get to be so fat?
Reversing the trend