N° 42 | February 2010

Nutrition information covered in mass media predicts fruit and vegetable consumption among adolescents


Exposure to mass media such as television, radio, the Internet, magazines and others, may have a considerable impact on eating habits in youth. Besides being used as a major channel for food marketing and advertising, mass media plays also an important role as a source of nutrition information. We investigated whether exposure to nutrition information as covered in mass media was associated with consumption of Fruits and Vegetable (F&V) among adolescents.

Cross-sectional nutrition survey data among adolescents

We analyzed data of a sample of 2,949 adolescents in vocational training in Vienna, Austria, with a mean age of 17.3 years (SD 1.7). Exposure to nutrition information sources was assessed by means of self-administered questionnaires, asking subjects where they usually obtained their information about nutrition.

Frequency of eating FV was measured by means of a food-frequency questionnaire, which asked about usual frequency of consumption of 59 food items during the previous months. Responses to the two items “fruit (fresh)” and “vegetables (raw and cooked)” were recorded into dichotomous variables (0 = less than daily; 1 = at least daily).

To which degree and direction do different mass media nutrition information sources predict daily F&V consumption?

Figure 1 shows the probability of daily FV consumption when adolescents reported exposure to the specific nutrition information sources. For example, adolescents who reported booklets as their preferred nutrition information source were almost 70% more likely to eat FV daily than adolescents who did not refer to booklets. This was irrespective of age, gender, ethnicity, body mass index, and weekly allowance.

Adolescents who reported advertisements as their nutrition information source were less likely to eat FV daily. Particularly, exposure to radio commercials decreased the probability of daily F&V consumption by 26% and 33%, respectively.

The use of fully adjusted regression models, which included in addition to the covariates mentioned above, smoking, leisure-time physical activity, and TV viewing, did not essentially change the findings.

Which potential mechanisms may explain the influence of specific nutrition information sources on FV consumption among adolescents?

Likelihood of exposure is increased if the adolescent is interested in healthy eating and actually searches for the information. However, exposure may also be accidental (e.g. advertisements). Subsequent behaviour may be affected by how the information is perceived, either consciously or subconsciously, with stronger effects when perception happens consciously. If perception leads to understanding and liking of the information, the “healthy eating” slogan may finally be used in making choices.

Adolescents who name booklets, the Internet, and newspaper and magazine articles as their preferred source of information are probably more interested in nutrition-related topics and actively seek them out. In contrast, nutrition information disseminated through TV and radio (particularly advertisements), schools, and relatives/friends does not necessarily require active search to achieve exposure.

Two other important characteristics of nutrition information sources are the quality of their content (in terms of objectivity and scientific soundness) and credibility of the source.

In the case of booklets, which are disseminated through pharmacies, general practitioners, and other health professionals, the nutrition information provided may be regarded as coherent and congruent with dietary guidelines.

Despite TV/radio (programs), relatives/friends, and school being reported the top three sources of nutrition information for adolescents, they were not associated with FV consumption. Disliking and/or misunderstanding due to poor content quality and/or low credibility of nutrition information covered in these sources may explain these findings.

The negative impact of TV and radio commercials on FV consumption among adolescents in the present study was as expected. That advertisements covered in newspapers and magazines showed no effect on FV consumption and may be explained by the less frequent and probably less persuasive exposure to these media.

To increase daily FV consumption among adolescents…

Print media, specifically booklets and newspapers, and the Internet should be emphasized in the dissemination of “healthy eating” slogans.

Freisling H, Haas K, Elmadfa I. Mass media nutrition information sources and associations with fruit and vegetable consumption among adolescents. Public Health Nutr. 2009 Aug 26:1-7. [Epub ahead of print] PubMed PMID: 19706216.