Why it is so hard to judge our calorie intake | Gustafson

Consumers often underestimated the calorie content of their meals.  - Courtesy
Consumers often underestimated the calorie content of their meals.
— image credit: Courtesy

Ever since calorie postings first became mandatory for chain restaurants in New York City in 2008, numerous studies have been conducted to determine whether consumers pay attention to the information and whether it has any influence on their behavior.

The latest of such studies, published in the British Medical Journal, found that even if calorie data are clearly posted on menus, menu boards and online, most restaurant patrons still dramatically miscalculate how much they eat.

For their survey, researchers at Harvard Medical School interviewed more than 3,000 adults, adolescents and parents of children who were visiting different fast food places in Massachusetts and Connecticut. When asked how many calories they thought their meals contained, the average estimate fell short by almost 200 calories.

"The mean calorie content of meals was 836 for adults, 756 for adolescents and 733 for children. On average, adults, adolescents, and parents of school-age children underestimated calorie content by 175 calories, 259 calories and 175 calories, respectively. Two-thirds of all participants underestimated the calorie content of their meals, with approximately one quarter underestimating the calorie content by at least 500 calories," wrote Dr. Jason Block, professor at the Department of Population Medicine, Harvard Medical School and lead author of the study report.

Somewhat surprisingly, the study found that the underestimation of calories was the largest at Subway, a chain that portrays itself as a provider of healthier choices, at least as far as fast food goes.

Eating just 100 calories in excess of the recommended calorie amount per day (for adults about 2,000) can add up to 10 pounds a year in weight gain.

Confusing information

Consumer advocates have long complained that the information Americans are getting about their food choices is still confusing, if not outright misleading. Also, the very concept of counting calories is somewhat opaque to the layperson. Most people assume that the portions they're being given are adequate. While that should be a reasonable belief, the truth is that sizes have kept growing exponentially since the 1970s. In fact, what looks appropriate to us now would have been considered over the top only a generation ago.

"Portion sizes have continued to increase through the first decade of the 21st century. Top fast food and restaurant chains continue to introduce new large-size portions. Food companies are introducing bigger burgers, burritos, pizzas, and sandwiches," says Dr. Lisa Young, professor for Nutrition at New York University (NYU) and author of the blog The Portion Teller. "The food industry has not responded to pleas from public health officials to reduce portions, and most Americans have become conditioned and have come to expect larger portions," she says.

To counter these continuing trends, Young recommends stepping up education and public health campaigns; setting stricter standards for food labeling and dietary guidelines; giving price incentives for smaller portions to consumers; and setting portion size limits in all food-service establishments. She also urges consumers to take responsibility for their eating behavior and design, if necessary, their own "portion size strategies".

Such measures can include ordering half-portions or an appetizer instead of a full entrée, splitting meals, going light on dressings and dips, and passing on the breadbasket, to name a few easily implementable steps.

The ultimate goal should be to become more sensitized towards one's nutritional needs. Some call this "intuitive eating," which, in the long run, may be the most effective way to judge when enough is enough.

Timi Gustafson R.D. is a registered dietitian, newspaper columnist, blogger and author of the book "The Healthy Diner – How to Eat Right and Still Have Fun"®, which is available on her blog and at  For more articles on nutrition, health and lifestyle, visit her blog, "Food and Health with Timi Gustafson R.D." ( You can follow Timi on Twitter, on Facebook, Google+ and on Pinterest.

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