seriously confused with how much i should be eating..

i'm 20 years old, 5'3, and 105-106 lbs -- down 20 lbs from a year ago (125 in may 07) it probably 'sounds' like i'm a decent weight or whatever. i totally agree, i'm comfortable with the weight i'm at. the problem is, i feel like i'm 'flabby-skinny' .. if anyone has any idea what i'm talking about. like, i'm skinny, but very little muscle - and i'd like to change that. i want to be more 'solid' rather than flabbyish.

my diet is generally like this..

Breakfast: 1 cup of oatmeal w/ 2cups of skim milk (my breakfast helps up the cals .. usually comes out to about 480ish)
Lunch: Salad with lots of veggies .. OR a sandwich .. depends.
Dinner: it varies .. but usually involves some lean meat like chicken and veggies etc

i eat about 1500-1600 calories a day. i know that doesn't sound like a lot - but it's a struggle to even eat that much on most days. i've posted about this before, but i have a gallbladder problem that causes me to feel EXTREMELY nauceous after i eat ANYTHING .. making it pretty hard to up the cals to gain some more muscle (without looking fat/big .. hard to explain). i'm getting my gallbladder removed on may 22, so hopefully that will solve that problem. i basically just want to be more solid and not have that extra jiggle.

so my question is, how many calories a day should i be eating in order to get rid of the flab without GAINING fat from eating extra? i've also posted this before, but i feel as if my metabolism is damaged because i also had mono for 7 months (another contributing factor to me losing weight). how am i supposed to know how fast/slow my metabolism is? i'm just really confused.

as of right now, i attend kickboxing classes (1 hr long) 3x a week and SOMETIMES i'll make it to the gym or run 1 or 2 other days. depends on how busy i am with school, but once that is over i plan to be able to hit the gym a little more.

any input is appreciated :]

bump, someone help meout

I calculate you need about 2100 cals a day in order to maintain your weight at a level where you're doing moderate activity i.e the kickboxing and gym.  Undereating leads to muscles wasting so you do need the extra calories.  If you want to tone up then choose strengthening, muscle building exercises alongside aerobic types ... I'm not an expert but the old 'low weight, high reps' springs to mind. 

And then adjust your food so that you're getting rather more protein in your diet.  A portion at each meal...  Lean meat, fish, eggs and so forth are good sources of protein.  And you should also look at vegetable proteins...  pulses/legumes, lentils, beans, chickpeas, quinoa, tofu, nuts, seeds...   With the exception of nuts and seeds, they are all very low in fat (which would help your gallbladder problem) but rich in fibre and minerals.  So if you added a 4oz portion of canned, drained beans or chickpeas to your lunchtime salad, for example, you'd be getting a better balance of protein to carbohydrate.

thanks for your reply!

if i keep up with the amount of activity i'm doing right now and eat 2100 cals, you don't think i'll gain weight? (let me rephrase that, because i KNOW i will gain 'muscle weight' - i mean as in i won't turn into a blimp and gain fat) -- thats the last thing i need!

cc suggests around 1790 for maintaining, so i'm assuming it's off?

Because you've been undereating on 1500-1600 you'll probably see a gain to begin with.  But that should only be temporary so don't panic and start dieting if you gain a couple of pounds....   I've worked out your intake based on the exercise you describe and your size.  2100 when you're very active (kickboxing).  1800 would be otherwise.  So if you aim to get to somewhere between the two... 1900-2000 on a regular daily basis and if your food was reasonably healthy then your weight would stabilise not far from where it is now. 

It's important to persist, even if you see your weight increase.  Your body has to get used to a little more food.