People Sometimes Lie about Their Health Behaviors; Health Halo Bias
Posted Jun 07 2013 12:00am
It should not come as a surprise to any reader of this blog that patients sometimes provide less accurate information (i.e., lie) when completing health questionnaires in topics relating to smoking behavior, drinking habits, and daily exercise. It's just human nature to do so and perhaps avoid a lecture from the physician during the visit. Such patient lies were discussed in a recent article (see: People lie about their health behaviors: Dartmouth study ). Below is an excerpt from it:
People lie about their health related behaviors. It’s a problem that has long bedeviled health research on issues ranging from diet to exercise to smoking. And it’s not just that we have faulty memories. Many of us stretch the truth to make ourselves seem more virtuous in the eyes of the person in the white coat. That makes drawing conclusions about behaviors that affect health from self-reported records tricky. [A researcher] has found a way around this problem—at least with regard to diet. [She] and her colleagues examined data on several years of household food purchases from a marketing database that tracks what people buy at the store by having them scan their groceries with a device at home. Paired with information on the same consumers’ health status and other demographics and data on the nutritional content of groceries, the researchers were able to track the link between factors such as income, food price, self-control, and health knowledge and the nutritional quality of their food purchases....Some of the researchers’ findings were expected. In families where the head of household is highly educated and interested in nutrition, purchases of fatty and sugary foods were lower than in others. But price had the greatest effect by far on the healthfulness of peoples’ food purchases. In families where there was a Type 2 diabetes diagnosis, total purchases of sugary foods declined. Other results were more surprising. The study examined the performance of people with “high self-control,” as defined by healthy practices such as regular exercise and infrequent consumption of fast food or late-night snacks. As expected, the self-controllers bought less junk food like sugary cola and potato chips. Yet they offset this benefit with greater quantity of “healthy foods” like yogurt and cereal, leading to greater overall consumption of calories and sugar. This paradox of consuming more because of a perception of healthy attributes is known as a “health halo bias.”
This notion of the "health halo bias" raised in the excerpt above is fascinating. People with a high level of self-control seem to buy less junk food but offset this "virtuous behavior" with purchases of foods advertised as healthy but which, in fact, may contain a unhealthy ingredients. Examples of these include yogurt, sport drinks, and some sugary cereals. Some interesting conclusions can be drawn from this point. The first is that people with high self-control, many of whom are probably highly educated, may be just as susceptible to manipulation by the media as everyone else. The second point, often emphasized in health articles, is the need to develop the habit of reading the ingredient labels of any packaged food. They are intended to enable purchasers to make more informed decisions about what to eat. Regarding this downward path of so many foods to "sugary drink status," you can now see the same trends in coffee shops. Various syrups and whipped cream are being added to coffee to turn them into highly caloric beverages (see: Calorie count in fancy coffee drinks can come as a jolt ).