Combining consumer welfare with corporate profitability is a challenge. With 65% of US adults either obese or overweight - based on World Health Organization body mass index (BMI) guidelines - food manufacturers face increasing legislative and regulatory burdens as the economic and social impacts of an overweight, unhealthy population are recognized.
One possible aid in battling the obesity problem has been to produce low-fat foods and label them accordingly. But do such labels help consumers in making healthy eating decisions, or do they mask other factors and lead to higher overall calorie consumption?
As one of a series of three working papers investigating the factors that influence food choices among overweight people and those of normal weight, Brian Wansink, the John S. Dyson chair of marketing and of nutritional science in the applied economics and management department of Cornell University and Pierre Chandon, assistant professor of marketing at INSEAD, examined how labelling affects consumption.
Wansink and Chandon designed three experiments to test whether the claim 'low fat' influenced consumption at a single eating occasion, if overweight consumers responded differently from normal weight consumers to a "low fat" label, and whether information about serving size had any ameliorative effect on the amount consumed.
In a lab study, the experimenters found that all subjects consumed more of a snack food labelled 'low fat' than of the identical snack food labelled 'regular', and that this was more pronounced in people who were overweight. The study also showed that the participants significantly underestimated the number of calories they consumed, especially of the "low fat" product.
Given that many foods labelled 'low fat' often contain at least as many calories as their regular counterparts, a market study based on results from the lab study and nutrition information provided on a range of snack products demonstrated that over-consumption of 'low fat' products would result in a higher calorie intake than if the consumer ate the regular product.
A field experiment then demonstrated that both normal weight and overweight participants believed that serving sizes for foods labelled 'low fat' were considerably larger than serving sizes for regular products. Participants also believed that the calorie content of 'low fat' products was significantly lower.
Food choice has subjective as well as objective dimensions, and this second study also examined whether 'low fat' labelling on two types of food - M&Ms (perceived as hedonic) and granola (perceived as healthy) - had any influence on feelings of guilt that participants might experience after consumption.
It was found that consumption guilt was affected not only by the type of food and whether it was labelled 'low fat', but also by the BMI of the subject, with overweight subjects expressing greater reductions in guilt. In other words, people felt less guilty about what they consumed if it was labelled 'low fat', and overweight people perceived these foods as basically guilt-free.
Finally, the experimenters tested whether information about serving size affected the response to 'low fat' labels. This study confirmed the earlier findings that 'low fat' labelling led to increased consumption and that overweight people consumed more than those of normal weight.
It then showed that when serving size was indicated, this influenced the amount of food consumed by normal weight participants, with serving size information appearing to override information provided on nutrition labels. However, overweight participants ate more of the 'low fat' food regardless of the serving size information.
The implications for regulators and food manufacturers are clear - current labelling initiatives to help combat obesity are not delivering the anticipated behavioural changes. The authors analyse related research that sheds some light on these findings, and suggest further avenues for investigation. They conclude that food marketers could play a major role in promoting beneficial lifestyle changes among consumers.