I recently started a diet four days ago, I'm not new to dieting but this is the first time I took it rather meticulously instead of just generally avoiding known **** foods like soda, sugar etc. I'm calorie counting and making sure I stay below a daily goal.

I started at 202, and now I'm down to 195. Yesterday I was at 200, now I'm at 194.8 and I'm a little concerned. I didn't attempt to have such a sudden weight change. I've been trying sticking around ~1700-1800 calories a day, and one day I was around 1400 although I didn't intend to do that(busy day).

My concern is that I'm actually not eating what I think I'm eating and my maintenance is perhaps higher than I planned?

I'm 6'1. The BMI index for athletes says I should be around 184. I lift and run frequently. Probably 5 times a week of either.

I find it difficult to calculate what my intake should be, running is easy to estimate burned calories but lifting is pretty difficult the gauge. Another problem is that I live on a campus whereas I have access to pre-prepared food, but I don't know what the the actual nutritional value of it is. I try to estimate but it can vary. For example I eat their granola but I have no idea what brand they use, and I've asked for nutrition info but they say they have a system that isn't out yet.

TLDR; if I'm losing that much weight, should I be eating more or is it something like water weight?

Based on all of that information, you're probably burning around 3000-3200 calories per day, and I'd expect you to lose about 2-2.5 lbs per week (rough estimates; it's impossible to predict exactly).

It could be water weight, or an inaccurate scale, or a combination of both. You couldn't have burned 5 lbs of fat in 1 day.

Keep weighing yourself and then you can adjust how much you're eating based on how fast you're losing. It's not healthy to lose more than 2 lbs per week.

Granola often has added sugar. Does it taste sweet? If you can find out the brand, you can probably find the nutrition info online.

Okay, so I guess I'm going to increase my diet a little.

I emailed him about the consistent food, like the yogurt from the stands and the granola, stuff I assume they use the same of everyday. He hasn't replied.
The granola taste like vanilla if that's any indication of sugar.

Ermac, my suggestion is to not weigh yourself so frequently. Weight can fluctuate so much from day to day that it becomes an exercise in frustration.

If you really feel the need to weigh yourself, I'd suggest no more often than once a week, weighing yourself under the same conditions at the very same time of day. Stretching it out to two weeks would be even better. Remember that it's only a number on a scale and in no way is the only way to monitor your progress.

I only see my weight when I'm in the doctor's office. Keeps me sane.

If you just started, you can see rapid "weight loss" which can be both water and glycogen. If, for example, you're used to eating a lot of carbs and you've just cut them, your liver can store up to 5 lbs of glycogen. It will dump the glycogen in response to the lack of carbs. On the flip side, if you eat carbs again, you can see the scale jump the opposite way as your liver puts glycogen back in storage. Water weight is also a factor- you'll see the scale jump up or down. For example, if you're sore from a workout the day before and you see the scaled jump 2-3 lbs, don't fret. It's just water in the muscles as your muscles repair. When the soreness goes away, the water weight will flush also.

I agree, every day is too much. Personally I weigh myself every 2 weeks. You can't make any conclusions based on 1 day anyway.

@Ermac: The granola probably has added sugar. I just looked at the nutrition facts from about 10 different brands, and every one had added sugar.

@EagleRiverDee: I didn't know you could lose that much from glycogen. That's interesting to know. (I've never been on a low carb diet myself)