Effectiveness of energy labeling in restaurant menu in reducing calorie in food selection and consumption : a systematic review

Abstract

Background Obesity was known to be caused by imbalance in energy in food consumption and energy output in daily activities. It has become a public health epidemic all over the world. Obesity associated diseases has brought large burden on the healthcare systems. Morbidity and mortality related to obesity are increasing. Overconsumption of calorie from away-home-food has a large contribution to the epidemic. Dining out frequently is associated with overconsumption of calorie in food selected and intake, in which its popularity is on the rise. Calorie labeling on restaurant menus has got mixed evidence on reducing calorie in food selection and consumption. This paper aims to review and synthesize relevant evidence among randomized controlled trials on the effectiveness of energy labeling in restaurant menu and total energy in food purchase and consumption so that possible causal relationship could be inferred and implications on future researches and policies could be provided.

Methods A literature search was conducted using PubMed and Cochrane Library to locate relevant articles in English that examined the effectiveness of calorie labeling on energy reduction in food selection and consumption from 1966 to 30 June 2014.

Results Twelve RCTs were included, with most of them (nine studies) conducted in the US. Overall, all the studies evaluated the effectiveness of calorie labeling on energy in food selection, 4 RCTs involved evaluated the effectiveness of calorie labeling on energy in food consumption. Studies were categorized into groups of real, laboratory and simulated settings for comparisons. In total, eight out of twelve RCTs revealed a significant calorie reduction in food selection with energy labeling, with proportional calorie reduction ranging from 8.3% to 36.7%. While in evaluating the effectiveness of calorie labeling on food consumption, three out of the four RCTs showed a significant calorie reduction in the intervention group, with proportional energy reduction ranging from 6.2% to 11.4%. One RCT showed a significant increase in calorie consumption after the study meal. Six of the 12 studies had recruited normal weight participants, and they found mixed results in calorie reduction of food selection with energy labeling, while 4 RCTs recruited averagely overweight participants and found significant calorie reduction in food selection. This difference in effectiveness of calorie labeling among various weight status of participants suggested that this policy would be more effective in secondary prevention of obesity rather than primary prevention. There was more evidence showing that calorie labeling is effective on reducing calorie in food selection in consumption in this systematic review among studies reviewing calorie reduction in food selection and consumption at a short period of time.

Conclusions Mandating calorie labeling on restaurant menus could possibly reduce the energy in food selection and consumption. A minimal reduction in calorie in food selection and consumption might possibly bring a large population benefit. However, more scientifically rigorous researches were called for a longer exposure period of time to evaluate its sustainability in altering people's eating behaviour.