In the two test lunches which included a first course, the salad
was served alone at the start of the meal; once, participants were
instructed to eat as much of the salad as desired, and once, to consume
the salad in full. After 20 min, participants were served the
main course and were instructed to eat as much or as little as they
liked. In the three test lunches without a first course, participants
remained seated in the cubicle for 20 min before the main course
was served, and were allowed to read magazines. In two of these
conditions the salad was served along with the pasta, once with
the instruction to eat as much as desired and once to be consumed
in full. During these two meals, the eating cubicle was unobtrusively
videotaped in order to characterize the participant’s pattern
of consuming the salad and pasta. In the control condition, no salad
was served with the main course. The interval between serving the
two courses was set at 20 min to allow sufficient time for the salad
to be consumed and begin engaging satiety mechanisms, while
allowing the first course and main course to be components of
the same meal. At all meals, the main course was accompanied
by 1 l of water, which could be consumed as desired. All food items
were weighed before and after meals in order to determine the
amount consumed to within 0.1 g. Energy and macronutrient intakes
were calculated using information from food manufacturers
and a standard food composition database (US Department of
Agriculture, 2010).