The UK researchers served identical meals to 47 normal weight and overweight participants, 24 men and 23 women. The information they received about the meal differed in that they were told the meal was either low fat/energy, baseline, or high fat/energy.
They found that study participants ate 3% more in the low fat/energy condition compared to baseline, with the effect more likely in overweight men than in women or normal weight men. There was no difference between baseline and the high fat/energy condition.
“Low fat/energy information can positively influence food and energy intake, suggesting that foods labelled as ‘low fat’ or‘low calorie’ may be one factor promoting the consumption of large food portions,” the researchers wrote.
Participants were also asked whether the information they received about the meal led them to eat more or to eat less. Thirty per cent said the low fat/low energy condition meant they enjoyed the meal more, leading them to eat more, compared with 11% in the high fat/high energy condition. None of the subjects said the low fat/low energy information caused them to enjoy the meal less, compared to 30% in the high fat/high energy condition.
The researchers also found significantly more participants said they would buy the low fat/low energy test meal in a supermarket (94%) compared to the high fat/high energy meal (49%).
“Public health strategies aimed at reducing EI [energy intake] through the use of low fat/low energy products should be aware of the potential power of the message that is relayed to the consumer, particularly the overweight consumer. Low fat/ low energy foods when eaten in moderation can help to lower overall EI – but only when the portion size consumed is also factored in,” they wrote.
Volume 65, 1 June 2013, pp. 153–158, http://dx.doi.org/10.1016/j.appet.2013.02.013
“Influence of nutrition labelling on food portion size consumption”
Authors: Mary T. McCann, Julie M.W. Wallace, Paula J. Robson, Kirsten L. Rennie, Tracy A. McCaffrey, Robert W. Welch, M. Barbara E. Livingstone