Calorie-labelling: does it impact on calorie purchase in catering outlets and the views of young adults?

Calorie-labelling of meals has been suggested as an antiobesity measure, but evidence for impact is scarce. It might have a particular value for young adults, when weight gain is most rapid. A systematic literature review and a meta-analysis was performed to assess the effect of calorie-labelling on calories purchased. Seven studies met the inclusion and quality criteria of which six provided data allowing a meta-analysis. Three reported significant changes, all reductions in calories purchased (-38.1 to -12.4 kcal). Meta-analysis showed no overall effect, -5.8 kcal (95% confidence interval (CI)=-19.4 to 7.8 kcal) but a reduction of -124.5 kcal (95% CI=-150.7 to 113.8 kcal) among those who noticed the calorie-labelling (30-60% of customers). A questionnaire, to gauge views on calorie-labelling, was devised and sent to young adults in higher education: 1440 young adults (mean age 20.3 (s.d.=2.9) years) completed the survey. Nearly half (46%) said they would welcome calorie information in catering settings and on alcoholic drinks. Females opposing to calorie-labelling were heavier to those who did not (64.3 kg vs. 61.9 kg, P=0.03; BMI=22.4 kg m(-2) vs. 21.7 kg m(-2), P=0.02). In conclusion, the limited evidence supports a valuable effect from clearly visible calorie-labelling for obesity prevention, and it appears an attractive strategy to many young adults.