Lesson learned: when it is a gym day, one must eat more beforehand (had to finish early because I was hungry)
So afterwards I allowed myself to be fed up - feast consisted of steak and three mini Haagen-Dazs tubs - and life is once again good.
So yeah. Eggs on the morning of lifting instead of fruit and yoghurt. The latter would be fine if I could somehow equate the calorie intake to that of the eggs, but I can't exactly eat a whole tub of yoghurt (well, in this household) so eggs it is.