Food Choice 47the simultaneous presence of both positive and negative values which seems
particularly pertinent to food choice, as individuals may hold contradictory
attitudes towards foods in terms such as tasty, healthy, fattening, and a treat.
Sparks et al. (2001) incorporated the concept of ambivalence into the theory
of planned behavior and assessed whether it predicted meat or chocolate
consumption. Participants were 325 volunteers who completed a ques-
tionnaire, including a measure of ambivalence assessed in terms of the mean
of both positive and negative evaluations (e.g., “How positive is chocolate?”
and “How negative is chocolate?”) and then subtracting this mean from
the absolute difference between the two evaluations (i.e., “total positive minus
total negative”). This computation provides a score which reflects the
balance between positive and negative feelings. In line with previous TPB
studies, the results showed that attitudes per se were the best predictor of
the intention to consume both meat and chocolate. The results also showed
that the relationship between attitude and intention was weaker in those
participants with higher ambivalence. This implies that holding both
positive and negative attitudes to a food makes it less likely that the overall
attitude will be translated into an intention to eat it.
Further, in line with other research using social cognition models,
research in this area has also added implementation intentions as a means
to predict and change dietary behavior which relate to the specific where
and whena particular behavior will occur. For example, Armitage (2004)
asked 264 participants from a company in northern England to rate their
motivation to eat a low-fat diet before being randomly allocated to either
the implementation condition or the control condition. Those in the
implementation condition were asked to describe a plan to eat a low-fat diet
for the next month and to formulate their plans in as much detail as possible.
Their food intake was measured using a food frequency questionnaire after
one month. The results showed that this simple intervention resulted in a
significant decrease in the proportion of energy derived from fat which could
not be explained by baseline differences in motivations, indicating that
implementation intentions had changed subsequent behavior.
A cognitive approach to food choice, however, has been criticized for its
focus on individual-level variables only and for the assumption that the
same set of cognitions are relevant to all individuals. For example, Resnicow
et al. (1997) carried out a large-scale study involving 1,398 schoolchildren
as a means to predict their fruit and vegetable intake. The study measured
social cognitive variables including self-efficacy and social norms, and
added additional cognitive variables including preferences and outcome