Labels on packaged foods such as nutrition facts, "low-sodium" or "fat-free" as well as calorie counts on restaurant menus, have to some extent encouraged healthier eating choices, say researchers.
The research, led by Tufts University researchers, found that labelling reduced consumers' intake of calories by 6.6 per cent, total fat by 10.6 per cent and other unhealthy food options by 13 per cent.
Labelling also increased consumers' vegetable consumption by 13.5 per cent.
In contrast, labelling did not significantly impact consumer intakes of other targets such as total carbohydrate, total protein, saturated fat, fruits, whole grains or other healthy options, the researchers rued.
"Many old and new food policies focus on labelling, whether on food packages or restaurant menus. Remarkably, the effectiveness of these labels, whether for changing consumers' choices or industry product formulations, has not been clear," said Dariush Mozaffarian, Dean at Tufts's Friedman School.
"Our findings provide new evidence on what might work, and what might not, when implementing food labelling," he added.
For the research, published in the American Journal of Preventive Medicine, the team reviewed 60 interventional studies — conducted in the US, Canada, Europe, Australia, and Asia.
When industry responses were evaluated, the team found that labelling led to reductions of both trans-fat and sodium in packaged foods by 64.3 per cent and 8.9 per cent, respectively.
However, no significant effects of labelling were identified for industry formulations of total calories, saturated fat, dietary fibre, other healthy components (e.g., protein and unsaturated fat), or other unhealthy components (e.g., total fat, sugar, and dietary cholesterol), although relatively few studies evaluated these endpoints.
"For industry responses, it's interesting that the two altered components-trans-fat and sodium-are additives," said Mozaffarian.
"This suggests that industry may be more readily able to alter additives, as opposed to naturally occurring ingredients such as fat or calories, in response to labelling. It will be interesting to see whether this will translate to added sugar," he noted.
Further, the team found no consistent differential effects by label placements (menu, package, other point-of-purchase), label types (e.g. nutrient content), suggesting information may be more relevant to consumers.