Some restaurant patrons may pick smaller portions when offered them

Having the option to order smaller restaurant side dish portions resulted in a substantial calorie cutback among customers, a study finds.

Some restaurants (mostly chains) have been criticized for selling outsized portions and dishes with too many calories, although some establishments have recently begun offering smaller meals and lower-calorie foods. A few studies have shown that menu labeling has been effective in getting people to make more healthful choices, but others reveal they have no effect.

This study was conducted at a Chinese fast food restaurant on a college campus and patrons were oblivious to what researchers were up to. Three experiments took place: In the first, the study authors wanted to see if offering a 25-cent discount for downsizing starchy side dishes would result in more people taking the offer than when no discount was offered. In the second, they noted whether accepting a smaller portion was more successful in encouraging moderation than posting calorie counts. In the third, they tested whether smaller portions appealed only to customers who would have otherwise tossed their leftovers. Results were measured via checking cash register receipts and weighing uneaten food.

In all three experiments, 14% to 33% of customers opted for smaller portions. In general, those who chose the downsized side dishes did not compensate by ordering more food and therefore, more calories. Overall, the calories they were served were lowered by more than 200.

Researchers also found no differences in the amount of uneaten food between those who took smaller portions and those who didn’t.

Very few customers asked for smaller portions without being prompted by a cashier. Posting calorie labels didn’t persuade people to order fewer calories.

The study results, the authors said, might appeal to restaurants and policymakers who want to support more healthful choices for people who eat out.

The study was published recently in the journal Health Affairs.