After 32 weeks in mouse barns, 35% of the females fed extra sugar died. This was twice the 17% death rate for female control mice.
There was no difference in the 55% death among males who did and did not get added sugar.
Males on the added-sugar diet acquired and held 26% fewer territories than males on the control diet: control males occupied 47% of the territories while sugar-added mice controlled less than 36%.
Males on the added-sugar diet produced 25% fewer offspring than control males, as determined by genetic analysis of the offspring.
Sugar-added females had higher reproduction rates than controls initially – likely because the sugar gave them extra energy to handle the burden of pregnancy – but then had lower reproductive rates as the study progressed, partly because they had higher death rates linked to sugar.