No you won’t screw anything up by occassionally fasting a little longer. It will in fact be beneficial to have occasional longer fasts, with more fat-burning time. 12 hours is not actually into “fasting” territory but will certainly helpful for calorie restriction so sometimes hitting 14h is good so you see more fasting benefits. The rule is to just stick to ‘at least’ your minimum fasting time (12h) every day. Anything extra is a win.
You are allowed to eat as regularly as you like within your eating window so 3 meals is fine. It is much better to have 3 filling meals than to be snacking through the day to meet your hunger needs.
I would say that you should a) just do what’s sustainable for you to do long term so you don’t give up, but b) that over time you should try and stretch yourself a little. Do 12h for a couple of weeks, then try and make 14h your regular fasting window. After a month or so of 14h, then 16h might seem less daunting. But see how you go and make gradual changes.
Congrats on taking this healthy step!
Sounds like a good start! I started with 12/12 and worked my way up too.
I now do 16:8 most of the time, but on weekends usually do 18:6. And I almost always eat three separate, smaller meals within that timeframe. It’s just my preference.
As long as you stay within your eating window and keep your total calories to where you want them, I don’t think it matters how you divide up the calories.
I think some people say they feel less hungry when they eat two larger meals instead of three smaller ones, but it’s up to you and how you feel.