Americans remain very overweight. According to the Centers for Disease Control and Prevention, about 38 percent of adults were obese in 2013-14, compared with 32 percent just 10 years ago. This is in spite of huge efforts to get people in the United States to eat more healthily.
Policy makers continue to believe that the problem is people's lack of knowledge that they are wolfing down calorie-rich foods. It is assumed that once Americans know what they are eating, they will eat less, or at least with health in mind. For this reason, many health advocates have called for restaurants to provide people with calorie counts of what they are ordering. Recent mandates mean that by the end of next year, calorie labeling will be required on all menus in chain restaurants and establishments selling food in the United States.
Because many restaurants are already trying menu labeling, we can look at how they have worked, or haven't, and begin to predict how this widespread regulation might function. For instance, researchers looked at data from 66 of the largest chains — those that posted calories and those that didn't — and found that average calories per item were 139 calories lower in restaurants that posted their nutritional information.
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http://www.nytimes.com/2015/12/01/upshot/more-menus-have-calorie-labeling-but-obesity-rate-remains-high.html?