losing 4lbs in a week?

It is most likely water weight going. you can go up and down from 1-6 pounds a day in water weight. If you are a woman, and it is near your "time of the month" you can fluctuate even more than that....

Weight loss isn't linear. It's not going to be a steady one pound rate. It could be water weight. It could be you won't see a loss the next 2-3 weeks. The whole "if you lose it too fast, it will come back on" thing is more talking about, imo, using a crash diet or habits that aren't sustainable. If you're exercising, creating new habits and eating in a way that you can for the rest of your life, then seeing 4 pounds in one week isn't a big deal. Also, if you have a lot of weight to lose, you might have weeks that you see a bigger loss, especially at first.

I never heard the theory that if you lose too fast you will put it back on. But a large weekly loss is almost always followed by a stall the following week. Always happens to me.

If you're just starting out, it's totally okay! Your body is adjusting! No big deal!

If you've been doing this a while now, you should probably make sure you're getting enough calories and not working too much of them off.

Also. Weight falls off easy if you've just gone to the bathroom. Remember that!

I think I may over exercise some days, like on Friday and Sunday because I didn't have Brazilian Jiu-jitsu so I went for a 2 hour walk without eating any extra food normal days for me are 1200-1000, I may need to eat more or make the 2 hour walks shorter or something

1000-1200 cals is quite low. What are your stats and what do you have your weekly loss goal at?

What was going on in the weeks leading up to the week with the 4 lb loss?

Many calorie counters report water weight gain masking fat loss for a couple weeks. Then "whoosh," a big drop in retained water reveals the fat loss that actually had been happening at a slow steady rate for weeks. Google "whoosh."

Losing or gaining X number of lbs in 1 week is not a concern.
Losing or gaining X number of lbs in 2 weeks is not a concern.
Losing or gaining X number of lbs in 3 weeks is not a concern.

Weight loss (and gain) is not linear. Watch overall trends. I would start to get concerned if you lost 3+ lbs/week for over a month, unless you are morbidly obese. If you are morbidly obese, it's normal to lose much more each week.

If you're just starting out, it's totally okay! Your body is adjusting! No big deal!

If you've been doing this a while now, you should probably make sure you're getting enough calories and not working too much of them off.

Also. Weight falls off easy if you've just gone to the bathroom. Remember that!

I think I may over exercise some days, like on Friday and Sunday because I didn't have Brazilian Jiu-jitsu so I went for a 2 hour walk without eating any extra food normal days for me are 1200-1000, I may need to eat more or make the 2 hour walks shorter or something

1000-1200 cals is quite low. What are your stats and what do you have your weekly loss goal at?

My weekly goal loss is 2lbs a week, I am allowed Your Daily Goal 1,200cals 150carbs 40 fats 60 protein 2,300 sodium 45 sugar

Depending on how much you have left to lose you may want to change that goal to 1lb a week, but that is up to you. I would truly encourage you to eat all 1200 cals you are given and eat back some of the exercise cals on your higher burn days.

The 4lbs could have been fat, or maybe it is water weight from one of your more intense workout days dropping off. More than likely it is a combo of both.

If your TDEE is 3200 and you eat 1200 that would be 4 lbs a week.

What I want to lose is 2lbs a week 8 ponds a month, should I change my goals and eat more cals?

Look back over your last month.

How much have you lost?
Is it inline with your goal?