How much extra benefit during 24-48 hour clean fasting over dirty?

I'm planning to restart a twice a week IF schedule for roughly 36 hours each. Back in the day, I had zero issues drinking coffee, but after pregnancy, I get terrible acid reflux if I do drink any coffee on an empty stomach (Espresso better than drip/French press, but not by much). I got used to drinking an energy drink in the morning, 3g carbs, 2g of which added sugar, 25 calories. This would mean I break the fast at least once during the period (twice if 48 hours), but marginally. Is it worthwhile to figure out a 0 cal/fake sweetener alternative (caffeinated water??? Something like that), or is this ultimately a blip in the radar? I appreciate that for weight loss it doesn't much matter, but are there enough benefits to bother with alternatives?

Answer

I figure if I’m going to fast, get all the benefits and keep it clean. If you need caffeine, try a nice black tea. I only do black coffee but sometimes I do a tea and it is just as satisfying even though it’s not my go to.

Answer

25 calories probably does not break a fast in practical terms. In theoretical terms, any calories “end” a fast but medical science shows it has a very small effect. It’s worth doing for electrolytes. The idea that you must have exactly zero calories for a week with no electrolytes so you have exactly zero calories is dangerous to some people. I naturally have very low potassium, so taking some in, even if it’s 10 calories, has a practical benefit that exceeds staying at zero calories. Dropping electrolytes really low can affect your endocrine system and even heart rate. If you need to, take in the few calories.