defining "moderation" for kid vices

[pamplona]

just wondering what others' thoughts are on how you decide about your kids' consumption of "vices" such as sweets and screen time. 

my DD is 2.5, and i started allowing a small amount of screen time (ipad apps and tv) right around age 2.  she currently sees about 1-1.5 hours of total screen time a week - spread out as 15-30 minutes a day, a few days a week.

i'm a bit of a health nut for the most part, but have also started allowing something sweet an average of twice a week. i do not personally count fruit or yogurt as sweets (she has those daily), but am more referring to stuff like granola bars or an occasional cookie, muffin or other treat.

anyway, i tend to question myself all the time about how much screen time and sweets to allow. at this age, i'm okay with some in moderation, but constantly go back and forth about what i consider to be moderation.  obviously there are many parents who are extreme on these issues - zero sweets and/or zero screen time or, alternatively - no limits.

for those who are seeking moderation, how do you decide what's moderation? your gut feeling? something more evidence-based?  changing definitions as your kids grow?

thanks - i know this is kinda broad/vague, but would appreciate any opinions.

[skycheattraffic]

The way I look at it, it changes with age and the seasons. In -20C weather when I can't even think of playing outside with DD, she will certainly watch a bit more TV than in the spring when we are outdoors at least a little almost every day. We go from 1-2 hours a day to 1-2 hours a week between the seasons but some limits always apply: no tv at all after naptime. TV in the afternoon winds her up and her sleep suffers. The only exception to this is if we're visiting; I can't exactly ask my FIL to turn off the news if we happen to be over.
A similar thing applies to food indulgences too. She will often go a couple of weeks without sweets and then we will visit both grandmas and she'll have sweets three days in a row. My rule there is that she must eat something healthy first so she doesn't just fill up on sugar but has a little treat instead. I don't know, I just kind of go with the flow. I don't hesitate to "forget" something if I feel she's had too much lately. I think the key is balance and flexibility. If you have a plan and you notice it isn't working, simply try something different. As long as screentime isn't a large portion of her day and the majority of foods eaten is nutritious then I would say you are doing a good job of moderating indulgences. Just my two cents