New to IF - early progress, and questions for those using it to lose weight and keep muscle

Hi everyone,

I am male, 46, and generally have been in ok shape (5’ 10”, 170ish, a little muscular, a little more fat than I’d like). Recently popped up to 190ish (at night, when I typically weigh many pounds more than after wake-up) and made the decision to be more rigorous about changing my food habits, with the goal of getting sub-170. Watched a bunch of YT videos, did some reading, and figured that trying IF with decent calorie restriction wouldn’t be all that hard for me (I usually skip breakfast or eat very lightly in the AM). I also heard that calorie restriction for too long reduces BMR (more than what the lower body weight would do anyway), so I wanted to try cycling calorie restriction and normal calorie eating to try to limit that.

I started doing some 16:8, some 20:4 mixed in, a break day from fasting every 3-4 days, and in the 10 days or so I’ve done it I’m finding it’s easy enough for me to do and the strict windows are great for eliminating late night snacking and junky sweet breakfast foods. My starting morning weight was closer to 186 and it’s down to 181. I am trying to lift weights near the end of fasting and break fast within 30 minutes of workout end with a protein/banana shake, followed by a meal later on.

Some things I’m curious about as I go past 2 weeks:

• If I want to keep my BMR from falling too much, does anyone have good experience with any cycles (e.g. 10 days restricted [like 500-700 calories], 4 days normal vs. 2 weeks:1 week, vs. 2weeks:2 weeks?) – any rules of thumb about how long before BMR takes a hit, and how long to go normal to “trick” the body back to normal BMR with normal eating? Supposedly the “MATADOR” study suggests cycling helps keep BMR from falling as much and aids weight loss
• Do people normally do IF every day? Any reason not to if I’m managing my calories/macros? I will likely just eat more during my windows during my non-calorie-restricted zones. I’ve heard advice to not do time-zone IF every day, but that assumed caloric restriction (again, because it would impact BMR), and I didn’t know if there were other reasons I should consider
• Any supplementation need (or strong suggestion) if IF is happening every day? (more water, salt, etc.?)

Sorry for the long post, but I have lots of questions and I’m very enthusiastic about the process of taking more control of my eating habits and ultimately my physique. Appreciate any advice people have to share, particularly about keep BMR going while doing IF and mild lifting (middle-aged man lifting, nothing crazy).

Thanks!

Andrew