In the 1970s, 15 percent of the American population was obese. Fast forward more than 40 years and rates of obesity have more than doubled. This increase has been attributed to a number of reasons such as increased intake of sugar-sweetened beverages and increased portion sizes. The common theme is that people are consuming more calories and the result is expanding waistlines.
Increased Calories Per Day and Obesity
According to the United States Department of Agriculture, in 1970, Americans consumed an estimated 2,169 calories per person per day, whereas in 2010, they consumed an estimated 2,614 calories. Refined grains and added fats and oils accounted for the biggest percentage of this increase. An increase in calorie consumption without an increase in calorie expenditure results in weight gain. One pound is equal to 3,500 calories. If you were to consume an additional 500 calories each day over the course of one week, you would gain 1 pound.
Over the past few decades portion sizes have grown considerably. Thirty years ago, the average size of a bagel was 3 ounces and 140 calories; today an average bagel is 6 ounces and 350 calories. An average cheeseburger was 333 calories in the 1980s; today it's 590 calories. Regardless of hunger and taste of food, people consume more when they are presented with a larger portion of food. Plate or container size can also influence food intake. The average plate size in 1970 was 9 inches; today's plate is on average 12 inches.
Sugar-Sweetened Beverage Consumption
Between 1977 and 1997, consumption of sugar-sweetened beverages such as soft drinks and fruit juices rose by 61 percent. In the 1970s, sugary drinks made up 4 percent of U.S. daily calorie intake; by 2001 that had risen to 9 percent. The serving size of an average soft drink in 1970 was 13 ounces and 156 calories, while the average serving today is 20 ounces and 240 calories. Consumption of sugar-sweetened beverages, particularly soft drinks, has been linked to an increased risk of overweight and obesity.
Food Away From Home
The number of eating establishments in the U.S. increased 75 percent from 1977 to 1991. Percentage of daily calories consumed away from home increased from 18 percent in 1977 to about half of total daily calories in 2004. Analysis of food eaten away from home done by the USDA found that it is higher in calories, fat and saturated fat and lower in fiber, calcium and iron than foods prepared at home. Because of higher calorie content and poorer nutrition quality, researchers have found a relationship between eating food away from home and obesity.
Managing Calorie Intake
With exposure to larger than recommended portion sizes, sugary drinks and higher calorie foods away from home it is important to manage calorie intake for weight control. Read nutrition labels. The nutrition facts panel can help you understand that portion sizes are often larger than you realize. Avoid eating straight from a container if it is more than one serving. Consider portioning large packages of food into smaller, more appropriate serving sizes. Eat meals from smaller plates to avoid over-serving yourself. Educate yourself on proper portion sizes by using tools like a set of measuring cups.
- United States Department of Agriculture: Food Availability (Per Capita) Data System
- Harvard School of Public Health: Sugary Drink and Obesity Fact Sheet
- Centers for Disease Control and Prevention: Do Increased Portion Sizes Affect How Much We Eat?
- United States Department of Agriculture: Let's Eat Out Americans Weigh Taste, Convenience and Nutrition
- United States Department of Agriculture: Food Consumption and Demand: Food-Away-From-Home
- United States Department of Agriculture: ChooseMyPlate.gov
Kari Leland is the director of clinical nutrition at Georgetown University Hospital and an Adjunct Instructor at Georgetown University. Leland is a registered dietitian with a Bachelor of Science in dietetics from Michigan State University and Master of Science in human nutrition from Eastern Michigan University.