Holiday food and cleansing

I'm about to get serious in treating candida/leaky gut

I'll be experimenting w/Zappers + lufenuron and other antifungals. Also iodine

Previously I've just focused on parasites, I'll still obviously be targeting them as well but I'm changing my approach after chasing them around

With the holidays coming up, I'm wondering what will the significance be of the occasional cheat treat of sugary foods, like baked goods IE cookies and treats

Will it render all progress and treatments useless?

What's the consensus? Obviously long term a low Sugar diet is best for health in any given situation but what about complex carbs too?