Weighty Problem: Oversized Portions in Restaurants Contribute to American Obesity

Angel Chen, a master’s student in nutritional sciences at California State University, Los Angeles, was shocked when she moved from Taiwan and began eating out. “Everything is double the size,” Chen said. “Fast food is cheap and bigger portions than in my country.”

The trend began in the 1970s as competition drove restaurants to lure customers with more generous helpings, equating larger portions to better value. In 1978 Americans consumed 15 percent fewer calories daily compared to 2018: 1,807 and 2,093, respectively. Eating out has become more frequent than it was a couple of decades ago and plays a significant role in increased calorie consumption mainly because of large portion sizes and calorie-dense meals, according to a study co-authored by Deborah Cohen, an obesity research scientist at Kaiser Permanente’s Southern California office.

“If you’re served too much food, you eat too much,” Cohen said. In her book, “A Big Fat Crisis: The Hidden Forces Behind the Obesity Epidemic—and How We Can End It,” Cohen argues that rather than a lack of self-control, the main culprit behind obesity is food marketing and promotion of oversized portions by restaurants.

In the 1960s, 13% of Americans were obese, according to data from the Centers for Disease Control and Prevention. Two decades ago the figure stood at 30%. By 2021, it had ballooned to 42%, and rates of diabetes and other serious diseases also continue to climb. According to a survey by the National Restaurant Association, the majority of adults who visit restaurants would prefer smaller-sized portions for less money.

“Restaurant portions have always been larger, always less healthy than anything we can make at home. They’re higher in sugar, salt and fat (and) they taste delicious, which is why people like eating out,” said Kathryn Hillstrom, professor in the Department of Nutrition and Food Science at Cal State, LA. “The marketing ploy of these restaurants is to sell more food cheaper, or at least more convenient than what people could make at home.”

In 1980, Congress ended the Federal Trade Commission’s authority to restrict food advertising. In 2016, over 20,000 restaurants and fast food chains, as well as beverage and snack brands, spent approximately $13.5 billion on advertising, according to the American Heart Association.

“You eat less when you’re at home,” Hillstrom said. But even if someone eats out frequently, she added, “when you go out, you sort of relax your food rules.”

In 2023, Cohen recruited three Los Angeles-area restaurants for Kaiser Permanente’s Standard Portions Study. The experiment aimed to find ways to steer customers toward better choices. Cohen helped create alternative “Balanced Portions” menus: 700-calorie meals with vegetable and fruit sides, less starch and carbohydrates, and limited or no sugary drinks or desserts.

“Everyone needs a different portion size depending on their height, their activity level, their gender,” Cohen said, adding that she’s not advocating for replacing large portions with smaller ones for everyone but rather offering an alternative menu. “Some people do fine eating the (larger) portion sizes because they’re athletes and active all the time … but there should be an option so that people can choose.”

First Szechuan Wok, a family-style Chinese restaurant; Delhi Belly, a casual Indian restaurant serving curry, biryani and tandoori dishes; and Dave’s Deli, a New York-style deli offering soups, salads and sandwiches, participated in the experiment. Each received around $2,000 for staff training, printed menus and other incentives.

First Szechuan Wok in Westwood offered a “dinner today, lunch tomorrow” option. Diners received their 700-calorie portion on the plate and more in a to-go container when they were ready to leave — two meals for the price of one.

“People want to get the most bang for their buck,” Cohen said. “If you struggle with finances, you’re going to stuff yourself as much as you can. And so it would be so much better if you served the right portion and then can have the rest packaged up. You don’t have to worry about the next meal.”

Dave’s Deli, in East LA, which is predominantly Hispanic, had already been offering smaller and cheaper portions of existing menu items. “I would get requests from customers (for) half a salad and a half a sandwich, or just half a salad,” said owner George Shalaby. “Some people want a smaller portion, some people want a larger portion. I’m very flexible and try to meet the needs of the customer.” After the restaurant participated in the four-month-long Kaiser experiment, Dave’s Deli kept the alternative menu.

The third participating business, Delhi Belly, located in an Asian food district in Alhambra, offered dishes with lean proteins, less cream, more vegetables and lighter cooking methods. Chefs reduced the amount of oil and ghee — clarified butter typical in Indian meal preparation — and focused more on spices and herbs.

“We’ve introduced smaller portion sizes for certain dishes, like our curries and rice, to help customers maintain portion control without feeling like they’re missing out,” said owner Sagar Ghosh. He discontinued the alternative menu after the experiment, calling it too time-consuming and labor-intensive.

As part of the experiment, customers were asked to fill out a log of what they ate at the restaurant and what they ate the next day and the day before. Cohen said this method proved to be ineffective in helping researchers understand how satisfied customers were with the smaller portions, as there was no visual to represent how many calories had actually been eaten.

A second trial of the experiment, currently underway, involves one new business, a Mediterranean restaurant The Green Olive, in Commerce, a city in southeast Los Angeles County. In this phase, participants are asked to take photos of their plates before and after they eat and to complete a survey on how full they felt.

Overall, participants who ordered from the alternative menus at all three restaurants walked away reporting satisfaction. “We found when they ordered from the standard portions menu, they had maybe two, three hundred or more fewer calories, and their satiety level was almost exactly the same,” Cohen said.

Outside of the Kaiser experiment, other restaurants have experimented with portion sizes. Next door to Delhi Belly is Road to Seoul, a Korean barbecue restaurant with a full bar, salad bar, appetizer buffet, all-you-can-eat entrees and an environment that encourages sharing and socialization. Such venues can be a hazard for people prone to overeating. But the self-serve format also lets diners set portion sizes that feel appropriate.

“Eating good is really part of Korean culture,” said supervising manager Tae Jang. “After the Korean War, my grandparents had trouble feeding themselves, so they always fed me. That’s just how we show love to each other.”

Smaller portions are the norm in Japanese culture. But with an American customer base, that tradition can go by the wayside.

At Pepper Lunch, another restaurant near Delhi Belly that specializes in Japanese teppanyaki — food cooked on a griddle in front of diners — manager Ty Ngo said a few customers have said over the years that they would prefer smaller portions that cost less, but most “told us they want them to be bigger,” he said.

Hillstrom envisions a multipronged approach to put a dent in the nation’s obesity crisis: smaller portions at restaurants, better nutrition labeling, more education, new eating habits and restrictions on marketing that encourages bad choices.

“Restaurants need to do their part. Schools need to do their parts,” she said. “We need to educate the heck out of people and then make the healthier option the easiest option and the most available option.”

Cohen agreed with a holistic approach that includes restrictions on food marketing.

“Anti-tobacco campaigns started in the ’60s, and they started showing the harms of tobacco and how the tobacco industry was manipulating people,” she said. “That made a huge difference. Smoking started going down dramatically.”

Policy around food portions in restaurants could drastically impact restaurant serving sizes and obesity rates, but Cohen said how portion sizes affect obesity is not discussed enough.

“We have to get the information out. We’ll have to recognize how important portion sizes are and also recognize that it is not their fault … shifting responsibility from the individual to the food environment,” she said.

This article was produced by Cronkite News at the Walter Cronkite School of Journalism and Mass Communication at Arizona State University.