Based on the scientific literature, we know that people who seek out and use calorie information are likely to be different from other eaters in many ways, including their motivation to cut calories. Sure, it’s possible that some people who looked at the information were persuaded to consume fewer calories, but it is equally plausible that those who were intending to order lower-calorie meals were more likely to seek out the calorie information.
By helping consumers make more informed decisions, calorie posting may be desirable even if it fails to reduce calorie intake. But effective policies to deal with obesity will need to involve much more than posting calories. People eat too much because calorie-dense foods are convenient and cheap, with large portion sizes priced to encourage overeating.
That’s Julie S. Downs, George Loewenstein, and Jessica Wisdom on the effectiveness of calorie posting nudges.
Incentivizing convenience of ordering low calorie food, by clustering these options together at the top of the menu, seems to have a significant impact. This indicates that traditional measures of informational provision are not always sufficient to motivate changes in unhealthy behavior.