Calories are at the heart of the two most important food issues facing the world today: food security and obesity. Yet, "calories can't be seen, they can't be smelled and they can't be tasted," leading to confusion about what exactly a calorie is and why it matters, said Marion Nestle speaking on campus Feb. 20.
Nestle, professor of nutrition, food studies and public health at New York University and a former visiting professor of nutritional sciences at Cornell, was the inaugural speaker of the Joyce Lindower Wolitzer '76 and Steven Wolitzer Nutrition Seminar, hosted by the Division of Nutritional Sciences' undergraduate nutrition group HealthNuts.
Nestle, whose talk had the same title as her upcoming book, "Why Calories Count: From Science to Politics" (scheduled for release in April), said it is difficult to estimate calorie consumption and calorie expenditure.
"You can only infer the number of calories you're eating by their effect on your waistline or their effect on the scale," Nestle said.
She also noted that public policies and cultural trends since the 1980s have contributed to a current obesity rate of more than 30 percent among American adults. Obesity is a complicated issue, she added, with genetics and individual metabolism playing an important role in determining weight. "Everyone who overeats gains weight, but some people gain much less weight than other people," said Nestle. However, "in a food environment that encourages overeating, it's really hard for most people to maintain their weight."
While physical activity levels have been relatively stable over the past 30 years, Nestle said, the amount of food available per person in the food supply has drastically increased.
"There is no question whatsoever that people are eating more now that they did in the 1980s," said Nestle, citing an increase in the food supply of 700 calories per person, per day, according to data from the U.S. Department of Agriculture.
Deregulation of agricultural policy and government subsidies for certain food crops as well as the pressure Wall Street has exerted on food companies to increase profits each quarter are the two main factors contributing to the surplus of available calories per person, Nestle said.
To increase profits, food companies are constantly seeking new consumer markets for their products. For consumers, that has meant portion sizes have increased dramatically, and food is readily available everywhere; these trends encourage consumers to eat more than they need. At the same time, government subsidies have made processed foods and grain products cheaper, while the cost of fruits and vegetables has increased.
Nestle's solution to these problems is to "get political" -- consumers can help change the food environment by supporting farmers' markets, neighborhood access to healthy food and accurate food labeling, among other things.
Graduate student Joyanna Gilmour is a writer intern for the Cornell Chronicle.