Echoing Rob's comment (I'm glad I read down before typing a bunch of junk)

So Original Poster - so many variables to see what works you kind of have to keep as many of those variable at least defined and stable - so, first, I'd define what you mean by casual low car (how many carbs a day, when do you eat, what do you eat)

I can certainly GAIN weight doing IF of 16/8 eating "low carb" so it's tuff to to give you and answer but the usual answer would be..."It depends"

Give us more info and we'll try to help you sort it out.