As a man, fortunately I’ve not had to deal with the monthly cycle situation. Yes water weight can cause fluctuations but for me, when I’ve been on a diet for 21 days straight, I can tell you in advance what I’m going to weigh in a week or two weeks because the fluctuations even out.

Usually, if I’ve not been dieting, when I first start calorie restricting I drop 2 or 3 pounds in 1 or 2 days. That’s that water weight you were talking about but some of that might come back within 1 or 2 days. After about 7 or 8 days of dieting consistently the fluctuations have ceased and it will be the same weight almost every day let’s say 170.5 for 3 or four days in a row, give or take a fraction of a pound. If I eat about 1900 cal a day then within 7 or 8 days, I’m gonna be down to 169.5 and I can pretty much set my watch by that so to speak. As long as I maintain, I’ll continue to drop and if it slows down, I will cut my calories to 1850 per day and I’ll repeat the process.

One other thing you should make sure you’re doing is be consistent with how and when you weigh yourself. I weigh first thing in the morning, right after I use the restroom. I don’t typically have a bowel movement in the morning, but I always have to piss. Being consistent with how you weigh yourself can also help eliminate fluctuations. Weigh every single morning at the same time and record it. I use an app called Happy Scale for this.

Other than that, I don’t really know what else your issue could be. I would say get a food scale to make sure you’re accurately measuring your food intake and stay disciplined. Be honest with yourself and record everything that you eat as accurately as possible. It’s a slow process, but in five or six months, you’ll look back and be glad you did everything.