Contradicting traditional assumptions, it seems that the big tip is lay off the meat. It seems that carnivory is very expensive as you get larger:
We show that the transition from small to large prey can be predicted by the maximization of net energy gain; larger carnivores achieve a higher net gain rate by concentrating on large prey. However, because it requires more energy to pursue & subdue large prey, this leads to a 2-fold step increase in energy expenditure, as well as increased intake. Across all species, energy expenditure & intake both follow a three-fourths scaling with body mass. However, when each dietary group is considered individually they both display a shallower scaling. This suggests that carnivores at the upper limits of each group are constrained by intake & adopt energy conserving strategies to counter this. Given predictions of expenditure & estimates of intake, we predict a maximum carnivore mass of approximately a ton, consistent with the largest extinct species.
So says Andrew P. Dobson, Princeton University.
The graphs look interesting.
We won’t be seeing a return to Indricothere & the like, at 15 tons apiece. Anybody running a dino-burger joint had better expect some stiff support costs, because even a 15t vegetarian would (literally) mow through tonnes of food every day.