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The real impact of healthier products on consumption and calorie intake

Final Report Summary - HEALTHY PRODUCTS (The real impact of healthier products on consumption and calorie intake.)

Several Western governments declared obesity as one of today’s most urgent challenges. Health organizations suggest the stimulation of healthier products to improve the quality, and reduce the quantity of food intake. We examine the effectiveness of this policy by studying the long-term impact of the first purchase of a low-fat product on subsequent purchase volumes and calories in the chips category. Theoretically, the first choice of a low-fat product may have a negative or positive effect on the long-term purchase volume and calories. On the one hand, people may have a strong internal motivation to change their eating behavior for the better. Choosing low fat instead of regular may fit into this general switch in lifestyle. If people are successful in improving the healthiness of their purchases, this should be reflected in a long-term decreased purchase volume and calories in the chips category. On the other hand, experimental research has already indicated the potential danger of low-fat products. People tend to overgeneralize the healthiness of the product and believe that the appropriate serving size of the low-fat snack is much higher. This makes people consume more of the low-fat variant than of the regular product, both in terms of volume and calories. When this single-occasion overconsumption is repeated several times, the increased purchases may form a new habit, which will lead to a long-term increase in purchase volume and calories. To assess the long-term impact of the first low-fat purchase, we first collected an extensive new and unique dataset which consisted of the purchase history of a panel of households, product information on the availability and type of health claims on the package and its nutritional content, and category and household characteristics. We use this dataset to test whether the first low-fat purchase causes a structural break to the monthly chips purchases of a sample of 311 households. We find that there is a lot of diversity in the long-term impact of the first low-fat purchase. For about 40% of the households, we find that the first low-fat purchase does not have a long-term effect. In contrast, for about 30% of the households, the first low-fat purchase leads to a long-term decrease in the chips purchase volume. These households probably have a strong and successful internal motivation to improve their lifestyle, which is reflected in an improvement (i.e. decrease) in their purchases in the chips category. For the other 30% of the households, however, the first low-fat purchase leads to a long-term overpurchasing. This result seems to be in line with the experimental literature that has already pointed to the potential boomerang effect of low-fat products. We show that this effect is not limited to the immediate effects that were already demonstrated in lab experiments, but can potentially translate into a long-term increase in purchase volume. The structural break analysis for monthly calorie purchases provides very similar results as the purchase volume analysis.
In a follow-up exploratory research, we examined potential differences between these different groups of households. As such, we find that households who relatively purchase more low-fat products in the year after the first low-fat purchase, have more chance to belong to the group of households for whom the purchase volumes increase in the long term, underlining the potential hazard of low-fat products. In contrast, households who are successful in improving their eating behavior as reflected in an increase in their purchase behavior of healthier categories (i.e. fruits and vegetables), have more chance to belong to the group of households who show a long-term decrease in chips volumes.
In sum, we show that low fat may indeed be dangerous as it leads to a long-term increase in the purchases of a substantial group of households. However, we also show that other households seem not to be affected by their first low-fat purchase, or even show an improvement in their purchase behavior. To the best of our knowledge, we are the first to demonstrate that low-fat purchases may have a long-term impact, contributing substantially to the literature that aims at discovering the impact of health claims on consumption. Apart from this intrinsic academic importance, we believe these results are also interesting for policy makers and the civil society who want to gain more insights into the effect of low-fat products in the fight against the obesity epidemic. In addition, also several companies have now communicated that they want to help in changing people’s eating behavior for the better. These companies struggle with the decision to put health claims on their product packages. Also for these managers, more research on the impact of health claims is essential.

Contact information:
Kathleen Cleeren
School of Business and Economics
Maastricht University
PO BOX 616
6200 MD Maastricht
The Netherlands