pooled from 5 large validation studies of both FFQs and 24-h dietary recall found
that the average correlation coefficients for the FFQ and true energy intake was
0.21. Using a single 24-h recall, the coefficient was 0.26 and 0.31 for the average of
three 24-h recalls. The average underreporting of energy intake was 28% with a
FFQ and 15% with a single 24-h recall. Reported energy intakes are poor
biomarkers of energy balance and the reported intake values often are not be
sufficient to sustain life (Freedman et al. 2014 ).
Many cognitive factors operate to produce faulty recall including: attention,
perception, retrieval, and response formulations that might involve prevarication
about social, medical, or psychologically sensitive food issues. Examples of these
issues are: individuals with diabetes consuming candy, excessive alcohol intake,
violations of religious food prohibitions, and a desire to please an interviewer
(Beaton et al. 1979 ; Dwyer 1999 ). Many evolutionary psychologists view the
ability to ignore or disregard some unique, idiosyncratic, detailed features of
experience as an adaptation so that these memories do not interfere with the exe-
cution of more immediate, and perhaps adaptive, decisions and activities (Cohen
and Bernard 2013 ). This is a plausible, but not tested explanation, if indeed con-
temporary humans make 200 food-related decisions daily (Wansink and Sobal
2007 ). Not all of these decisions are conscious ones requiring deliberation, some are
habitual. However, people report making an average of only 15 such decisions daily
(Wansink and Sobal 2007 ). If a person is restricting food intake for weight loss, the
hypervigilance required in a food-cue laden environment is a source of additional
stress (Cohen and Bernard 2013 ; Polivy and Herman 2006 ).
Furthermore, visual reminders of the type and amount of foods consumed, the
debris of meals—chicken bones, ribs, pits from fruits, mollusk shells, are becoming
less frequent with fast and prepared foods. Globalized foods are marketed without
visible waste: buffalo chicken wings, chicken nuggets, barbeque rib meat, andfish
fillets are all boneless, nuts are shelled, fruits are peeled, cored, and sliced. A glance
at the menu shows that McDonalds ( 2014 ) is an exemplary model. Once foods are
consumed, there are no remnants or reminders of what or how much was eaten
except, perhaps, easily disposed of bags, paper cartons, and Styrofoam boxes.
Because humans value convenience and prefer to conserve physical energy,
these foods have an enormous appeal (Lieberman 2006 ; Schachter and Rodin 1974 ;
Thaler and Sunstein 2008 ). A cost/benefit model using energy as the currency in
which there is a positive return on investment is a fundamental tenant in optimal
foraging theory (Kamil et al. 1987 ). Wansink has shown that making small changes
of induced inconvenience, a little higher energy cost, had an advantage in reducing
caloric intake. Moving candy dishesfilled with Hersey’s kisses from secretaries’
desks to afile cabinet 6 feet (183 cm) away reduced the average intake from nine
kisses (225 calories) to four kisses (100 calories) per day (Wansink et al.2006a).
‘The more hassle it is to eat, the less we eat’(Wansink 2010 : 84). Conversely,
changes that make choices easier with less effort and more salience can also be
structured. Thaler and Sunstein ( 2008 ) refer to this as choice architecture in which
environments are designed to influence healthier choices. In one school cafeteria
experiment, students were‘nudged’to make 25% more healthy food choices by
206 L.S. Lieberman