For nearly every overweight person on the planet, there exists another person that is undernourished. The United Nations Food and Agriculture Organization estimates that, as of 2012, there are 870 million people whose “food intake [...] is insufficient to meet dietary energy requirements continuously”. How can these two extremes - those who consume too few calories, and those who consume too many - coexist?

America is addicted to junk food, and the rest of the world isn’t far behind. Salty, sugary, and fatty processed foods are a global health epidemic, and an addiction that is becoming harder and harder to kick. These are only some of the conclusions in the new book “Salt Sugar Fat” by Pulitzer Prize winning investigative journalist Michael Moss. The New York Times has an excerpt from the book here. It’s well worth your time.

Moss spent four years investigating the world of food that is meticulously engineered to delight our taste buds without overwhelming them (an optimum appropriately referred to as “the bliss point” – think of how eating Doritos is satisfying without becoming too satisfying), all the while contributing to an increasing number of people classified as overweight or obese.

Over one billion people on planet Earth are considered overweight based on their Body Mass Index (BMI), and of those, some 300 million are clinically obese. Think this is far-fetched? You might technically be overweight or obese. Using this handy BMI calculator, I scored a 23, which is below the threshold for overweight – although not that far off.

Cravings for processed foods are global. The shift from “good” foods (complex carbohydrates) to more convenient, longer lasting foods (those that pack more energy density and are rich in sugar, salt, and saturated fats, designed to keep on a truck or store shelf for months) combined with a sedentary lifestyle has resulted in a global fattening. This shift usually follows economies that develop away from labor-intensive jobs, but it’s also present in economies whose population craves inexpensive calories.

The health concerns with overweight and obesity are well documented. In 2003, The World Health Organization (WHO) released a report (PDF) documenting this epidemic, noting that increased consumption of energy-dense, nutrient-poor foods, rich with sugars and fats, and coupled with reduced physical activity, have led to obesity rates tripling since the 1980s. Those who are overweight or obese face higher risks of hypertension, Type 2 diabetes, and cardiovascular disease. These health issues are a drag on the economy, to a tune of some $300 billion each year in the United States alone.

There is some good news: in the past two decades, the number of undernourished has fallen by 132 million people, putting the Millennium Development Goal (MDG) of reducing the percentage of undernourished to 11.6 percent of the population by 2015 within reach. Yet, as the WHO report finds, the obesity epidemic is not restricted to industrialized nations; the increase in obesity rates is often more pronounced in developing countries.

Food engineers and scientists have made incredible breakthroughs in how modern food is produced, transported, stored, and consumed. A major question is how can the global food system feed a growing population that is increasingly leaving fields for cubicle farms and adopting the western lifestyle - without exacerbating the obesity epidemic?