prominently displaying milk and fruit, and making the unhealthy choices of candy
and chips less visible and accessible (Thaler and Sunstein 2008 ). Other cafeteria
studies have manipulated menu choices, placement of salad bars and payment
options to influence the consumption of more healthful foods (Just et al. 2008 ; Just
and Wansink 2009 ). Wansink ( 2010 : 88) reports two military mess hall interven-
tions in which soldiers drank 81% more water when the pitcher was placed on the
dining table compared to a side table and a 42% increase in milk consumption when
the machine was 12 feet (366 cm) rather than 25 feet (762 cm) away. Restaurant
salad bars manipulate choices by placing plate-filling, low calorie, and less
expensive greens at the beginning and more calorically dense and expensive foods
(i.e., meats, cheeses, chicken salad) toward the end. Both high salience and reduced
effort or convenience are primary factors influencing these behaviors.
The desirable reduction in food-related effort and energy conservation may have a
broader basis in human energy budgets. Recent studies on energy expenditure
(Kcal/day) in large samples (Pontzer et al. 2012 ) including a meta-analysis (Dugas
et al. 2011 ) comparing the Hadza—a contemporary foraging group—and larger
samples of populations from farming, developing, and industrialized countries,
demonstrated surprisingly small average variations in physical activity levels (PAL)
and total energy expenditure (TEE), adjusted for weight and age. For example, the
ranges for PAL (TEE/BMR) were Hadza, women (1.44–2.53), men (1.67–2.96);
western industrial samples, women (1.21–2.54), men (1.56–2.42); and farming com-
munity samples, women (1.44–2.62), men (1.65–2.51) (Pontzer et al. 2012 :Table1)
These researchers conclude that the similarity in PAL across a broad range of cultures
challenges the causal role of decreased energy expenditure in industrial life styles as a
major contributor to the obesity pandemic. Pontzer et al. ( 2012 ) hypothesize that
human daily energy expenditure may be an evolved physiological trait largely inde-
pendent of cultural differences.
Other factors strongly influence eating behaviors in both visible and invisible,
conscious and unconscious ways. Some of the influence is genetic; for example, the
ability to produce lactase throughout life in sufficient quantities to digest milk and
other high-lactose dairy foods (Durham 1991 ; Swallow 2003 ) or the ability to taste
phenylthiocarbamide (PTC) or 6-n-propylthiouracil (PROP) and related naturally
occurring goitrogenic compounds in plants (Bartoshuk et al. 1994 ; Greene 1973 ).
Biomarkers for both of these traits are readily experienced with varying degrees of
sensitivity and specificity in that primary lactase-deficient/lactose-intolerant people
will experience gastric upset,flatulence, and diarrhea after ingesting foods high in
lactose and tasters of PTC or PROP will sense a bitter taste on exposure to these
substances or foods (e.g., Brussels sprouts, cabbage). Clinical biomarkers involve
ingesting a test dose of lactose followed by measurements of serum glucose (a rise
is an indicator of lactose digestion) or exhaled hydrogen (a rise is an indicator of
lactose intolerance) or genetic tests (Patient.Co.UK 2013 ). PTC- or
PROP-impregnated test strips that are chewed, or sipped dilutions of known con-
centrations of PROP, elicit a bitter taste to tasters but are nearly tasteless for
non-tasters. Genetic tests are rarely used (Taste Science Laboratory 2012 ).
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