Intermittent fasting

Fasting can help people lose weight because it reduces the number of 'eating hours' which can make it easier to stick to a calorie goal. It can also help control hunger. These are personal preferences, which don't apply to everyone, so it's a matter of experimentation.
Other than that, no benefit imho.

As for water retention, these are relevant factors: stress (mental stress, lack of sleep, (excessive) calorie deficit, (excessive) exercise,...), exercise (water retention for muscle repair), carb intake (they're called carbohydrates for a reason), salt intake,...
You shouldn't concern yourself with water retention too much, when we want to lose weight it's fat we're concerned with. A healthy body knows how to balance its water level and fluctuations are perfectly normal.

By the way: losing 10lbs in 4 weeks is very quick, only appropriate if you weight 250lbs or more. If you weigh less, you really shouldn't be aiming to lose any faster. Fast weightloss carries health risks such as muscle loss, gall stones... A rate of 0.5-1% of bodyweight per week is often mentioned as a good rate.

Weight management comes down to calories overall. IF can help some people better manage their calorie (energy) consumption, but there isn't any more magic to it than that. Assuming you're supposed to eat 1640 calories per day to safely lose weight, you would eat that same number of calories whether you ate 3 or 6 or 1 or 2 meals per day...it makes no difference other than personal preference of eating patterns.

For weight loss, it's calories that matter directly. If IF helps you stick with a calorie goal, then do it. If it doesn't, skip it (if weight loss is the only reason to choose it). Weight loss has enough challenges without adding extras that make it more difficult for the individual, unless they have other strong reasons to do those things.

Lots of us here lost weight without fasting. I did and do eat anytime I wish, from shortly after I get up in the morning, right up until bed time. I lost from just over the line into class 1 obese to a healthy weight in a bit less than a year, and have stayed at a healthy weight for 7+ years since, after around 30 previous years of overweight/obesity.

As far as I am aware, water weight is what goes first, therefore after the initial weight loss it should be fat, sometimes even muscle that goes if proper strength training is not incorporated.

Well . . . we do tend to lose some water weight at first, so the first week or two may show a quicker drop in scale weight than will occur as time goes on.

But even at first, it's likely some fat loss, some water loss - if truly at a calorie deficit, that energy deficit is made up somehow, and water loss won't do it.

Sure, risk of muscle loss is reduced with strength training, but IMU other exercise types can make a contribution to retaining muscle, and good nutrition (especially adequate protein) is also part of retaining muscle mass, plus avoiding aggressively fast weight loss.

I can lose, maintain, or gain while eating 12 hours a day.

What I find helpful to focus on is foods that fill me up. That's how I maintain a calorie deficit. For others, meal timing is of course a valid strategy; it's just not for me.

What I find helpful is to meet or exceed my protein and fiber targets, and to not exceed my fat target. I use the MFP defaults. If I were sedentary, I would up the protein target.

I don't find fat especially satiating, and at 9 calories per gram vs protein and carb's 4 calories per gram, it adds calories more than twice as fast.

I am on my third weight loss journey here at MFP. As usual, I lost 30 lbs relatively easy over 2 minths on a 1300 calorie plan for my age (69) and the slightly active category I chose, along with daily yoga exercise and physical therapy. Then I plateaued for about a monrh as I always seem to do. I finally decided to switch things up and try something new, so I chose intermittent fasting which worked for my daughter. I fast after my last 8 PM snack and brunch around 10 or 11 AM next morning. I found that combining my breakfast and lunch is only 400 calories, whereas separate meals were adding up to around 600 calories making my dinner smaller or going over. I'm still eating two 200 calorie snacks, and a that allows me a slightly larger dinner, 400 calories and one 100 calorie hard seltzer a day. At any rate, it has kick started my weight loss again. Hopefully I can lose at least another 30 lbs and maybe even few more after that. IF was a little hard at first because I would wake up hungry, but my body has now adapted and I do my morning exercise first, then it is time to eat. I'll let everyone know how I do long range. BTW I eat high protein, about 35%, low carb around 25%, and try to keep fat under 40% as I tend to eat way too much saturated fat for my well being.