Amount of diet consumed
We found a significant three-way interaction between diet, pronotum
width, and tray number (i.e., time period of feeding trial) on the
amount of food that males consumed during the 3-week feeding period
(F 6, 1776.32 = 3.16; p =
0.0044; Fig. 1). Males held on the high carbohydrate diet (P:C 1:8)
consumed more food than those maintained on the high protein diet (P:C
5:1) early in the feeding period, but after the second tray, this
pattern was reversed, and males on the high protein diet (P:C 5:1)
consistently ate more food than those on the high carbohydrate diet
(Fig. 1A). There was also a significant interaction between diet and
pronotum width (ANOVA: F 1, 313 =
3.89; p = 0.04954) with respect to the average amount of food
eaten, which increased with body size in both treatments, but more
steeply in males held on the high protein diet (Fig. 1B). To account for
this size-based variation in food consumed in subsequent analyses, we
included the average amount of food consumed for each individual, as
well as their pronotum width, as covariates in the full models.