What is going on with health?
Was your health high on a friday and low on a saturday?
Maybe you forgot to check the influence of the WvW buffs your server achieved during the week?
Yup, it sounds to me like that’s simply the WvW health buff that everyone on your server gets. The number to look at for your actual health is the number shown on the Hero panel. That number doesn’t take food or other buffs into account and shouldn’t fluctuate. The number shown on the health globe takes WvW and other buffs into account.