Water weight...

Maybe 1 lb fat? Mostly water but that's ok. Perfectly normal. Keep it up.

Did you ever track your usual diet? If so, you can do the 3500 calorie math and have a good idea.

Did you weigh yourself before you started losing? Did you know how much your weight changes during the day? Mine at my higher weight moves by around 4 lbs between the heaviest (after dinner) and the lightest (after work but before dinner) with the morning weight being in the middle. So for me personally I'd attribute about 4 lbs to being water weight since that's my usual fluctuation. But you should still think of it as a good thing, your body is letting go of the water before it lets go of the fat, and it's a great start!

Marigold000 wrote: »

I've lost 5lb in my first week of eating 1300 calories a day and was just wondering how much of that is likely to be water weight and how much actual fat? How much did you guys loose in your first week of eating healthy?

My best guess would be about 4 lbs of water, 1 lb of glycogen, and roughly zero actual fat as yet. That's OK! With glycogen stores more or less depleted, you're now ready to start burning fat. A moderate deficit is best to minimize the loss of lean body mass as you lose fat.

I was eating "healthy" before I started losing weight (if you define that as a diet with a reasonable amount of veggies, whole grains, legumes, fruits, and moderate amounts of animal protein, more lean than not) -- I was just eating too much overall. I started tracking my food and exercise on MFP mid-week, but other than that my weigh-ins were on the week-end. I lost 1.5 lbs in the first three days, and then another 3.5 lbs in the first full week after that--so 5 lbs in 10 days. After that I continued to lose pretty steadily at about 2 lbs a week (even though I was set for 1 lb a week -- apparently MFP and my body don't agree on my NEAT) for about 3 and a half months (a little slower before and during my period, a little faster just after).

cafeaulait7 wrote: »

Did you ever track your usual diet? If so, you can do the 3500 calorie math and have a good idea.

OP would also have to know if on the "usual diet" she (I'm assuming she based on username) was maintaining or gaining weight. This is just a pet peeve of mine, because I see advice (not just in MFP forums but in blogs and newsletters --quoting advice from "dieticians") to "just cut 500 calories a day from your current diet, and you'll lose a pound a week." Well, no, not necessarily. Lots of people's current diet has them on a trajectory to gain 10 or 15 or 20 lbs a year, and some are even gaining faster--i.e., their current diet is what has led them to be overweight in the first place. A 500 calorie a day cut from their diet may only allow them to lose a half pound a week, or maintain, or even continue to gain slowly if their recent "usual" diet has packed on 30 or 40 lbs in the last six months -- that's not the way I gained weight, but I see plenty of accounts of people on these forums who have had these rapid gains.