Happy Birthday.
I’m not an expert and have been following this sub doing a lot of starts, stops, loose , gain, start overs.
Some on this sub will say no sugar, creamer nothing. And others will call it a “dirty fast” and deem it ok.
So this will be a trial and error maybe but you know your own life, demands, tolerance’s, goals and body. And luckily IF is flexible enough that each successful individual has made it work for them.
Most build up to a long fast by starting out with a shorter time like a 16/8 or less. Some go full out of the gate OMAD(one meal a day) or ADF(alternate day fasting) but it all depends on the person.
The common themes I’ve seen is drinking the water, CICO, eating within their caloric range and some cut back on carbs, sweets and alcohol making them permissible during certain times. Others swear by keto and IF.
I personally say if your goal is weight loss only and you’re not concerned with the benefits of autophagy then add your zero calorie things but be warned it may drive your blood sugar up a bit and get your gherlin a chrurlin for real food. Once upon a time I was on a doctor’s supervised diet of a mere 500 calories a day of these shakes and yes, it was hell. Anyway they made certain things permissible and one of those was Walden Farms creamers and pretty much all their products. I never tried it so I can’t vouch.
If you want autophagy then nada but plain teas, waters, coffee. At least that is what I’ve learned but I may be incorrect.
But take it easy on yourself, realize it may be trial and error. My first successful go around I did a dirty AFD and on the fast days if I got to a mental breaking point I’d have broth with a hard boiled egg and miracle noodles and make a “ramen” of sorts. And the next day I’d do an extended fast that I would break around noon. After awhile I could go longer.
Right now I’m freaking famished but holding strong. Trying 18/6 but my body will respond best to ADF as before but it’s a work up again.
In this time the weight came off but I also experiences my body shrinking and shifting. So the scale won’t be the sole representation of progress and changes. And you think about food less and less over time, that was weird.
Also helps to have distractions for the hungry times. I can’t focus if I’m too hungry but I can veg out and do mindless tasks and things and that helps pass the time, keeping busy. Best of luck, much success.