Enough?

I occasionally question whether or not I eat enough calories to fuel my lifestyle, and I wondered if other people had any advice and/or input to help me figure it out. I'm 19 years old, almost 5'6, and 125 lbs. I exercise a lot; I usually do about 80 minutes of tough cardio daily, whether it's running, biking, stairmaster, tennis, etc. or some combination. I also lift for about 20 minutes daily and do abs. I am not interested in losing weight. I just want to know if I am getting the proper nutrition to fuel my daily routine and keep me fully energized and performing at my full potential. I usually eat about 1900 calories per day, for example:

Breakfast: 1 cup Cheerios and 1/2 cup Crispix mixed into a dannon light 'n fit yogurt; a mango (350cals)

Lunch: A turkey sandwich with 2 slices whole wheat bread, cheese, lettuce, mustard, and relish; an apple with 1 tbsp peanut butter or nutella (500cals)

Snack: An apple and a banana (200cals)

Dinner: A salad with a whole can of tuna, 1/2 avocado, 1/4c goat cheese, tomato, onion, balsamic vinegar, salsa; a sweet potato (550cals)

Dessert: Edy's slow churned ice cream (300 cals)

I appreciate any input!

Based on the info you provided and considering how active you are, I doubt that you are getting enough calories, assuming that you want to maintain and not lose weight.  The average of the sites I went to and plugging in very active for your activity leve,l I arrived at the conclusion you could be consuming 2400-2500 and still maintain.  Certainly, 1900 would seem to me to be encouraging weight loss.  You might want to weigh yourself each morning upon first waking an going to the RR, for a couple of weeks, to see if you are maintaining on 1900.  Or maybe you would find that you are slowly losing weight. 

definitely not eating enough, at 4'11 i maintain on 1900-2000 and i am much less active than you. i usually do 45 minutes of moderate cardio a day and maybe 10 minutes of weight lifting every other day and 1 hour class once a week.

I agree that I could/should probably be eating more. It's just that I've been eating this amount (1900-2000) for a long time now and it doesn't seem that I have lost any weight (though I'm not 100% sure because I never weigh myself). If anything, I think my body composition has changed to a much higher ratio of muscle to fat. My clothes are a little loser and I am more toned. I fear that if I start to eat more, I will put more fat back on, though part of me knows that won't happen if I continue to do as much cardio and weight training as I do now. I may actually be able to build more muscle! It's just a mental thing. I guess maybe I should try it for a couple of weeks and see the results.

Original Post by cbmonagan:

I guess maybe I should try it for a couple of weeks and see the results.

 That's not a bad start.  http://www.bcm.edu/cnrc/bodycomp/bmiz2.html  This site is calibrated for the under 21s.  If you're 5'6" , 125lbs and 'very active' then you're looking at 2870 cals a day, possibly more

You may well gain some weight, be prepared for that.  However, if you're only maintaining your current weight through persistent undereating then it's almost certainly not your natural healthy weight. A healthy weight for someone your size goes from about 117lbs to 161lbs.... so even if you stabilised at a slightly higher weight by eating the right amount to sustain your activity, you'd still be well within the healthy zone.  If you're very active, most of the weight you'd gain would be muscle rather than fat.