I am guessing you take something like vyvanse? I take one 40mg pill of vyvance every morning before school. I have been taking it for about almost two years now. I had the same problem when I first started taking the medicine. I would NEVER be hungry. It wasn't that I didn't want to eat, I just didn't feel hungry. For the first month, it also felt as if I was wearing a mask.. I was really dull and had a neutral emotion ALL THE TIME.. I did notice that I was more attentive in class, but I also got more annoyed with background noises. For example, before the medicine I could handle watching TV while someone was talking.. But now, if someone is talking while I am watching TV, it seems like I can't consentrate.. The reason this happens is because you are trying to pay attention to two things at once. Your medicine is making your gut delay decisions made by the brain, thus making you think before you do.. But at the same time you are trying to comprehend the TV show, while trying to tune out the person talking... The same thing happens to me when someone taps their pencil or whistles.
SOME ADVICE FROM ME:
1. Take your medicine in the morning
This is very important because your medicine will last 10-14 hours then begin to ware off. Taking the medicine in the morning will mean that you will not be hungry DURING the day, while you are at school/work, not really eating too much anyway. But then, in the afternoon when you are home the effect of the medicine will ware off and you can eat up.. Be prepared not be hungry around dinner time, but be hungry RIGHT before bed.. Make sure you have things you can prepare on a short notice.. Take advantage of ANY time that you are willing to eat, because it may not come again in that day..
2. Eat breakfast/food with your medicine
I recommend eating something small like a granola bar or a cup of cereal. This will help settle your stomach and will let your medicine take effect (reach your gut) quicker, meaning that it will ware-off earlier and will also get you awake and ready BEFORE you need it.
3. DO NOT try to "gain" your lost weight by eating unhealthy
When I first realized my loss of appetite, I thought that eating unhealthy and fatning food would make up for the other food I didn't eat. I was SOOO wrong. Turns out that when you eat unhealthy WHILE you are eating well below your recommended intake, you will get REALLY sick.. I was throwing up, coughing, and had a crazy bad upset stomach. Make sure you are eating A LOT of protein and vitamins. (I recommend multi-vitamins and omega-3 pills if your eating habit is REALLY bad)
4. Don't skip lunch, no matter how much you want to
Literally, if you have to eat only a few goldfish, then do it. FORCE yourself to eat as much as possible during lunch. I skipped LOADS of lunches. And it will guarentee a loss in weight as well as a loss of matabolism and even loss of strength and energy. Anything you can get in your stomach to settle it is really helpful.
5. USE LIQUIDS AND SMOOTHIES TO YOUR ADVANTAGE
The one thing I recommend the most is using liquids and smoothies to your advantage.. The one thing I remember most when starting the medicine is that I lost my appetite, but I was always willing to drink something. Use this to your advantage. Whip up a smoothie with some fruits and vitamins in it. This will help your intake of natural sugars and minerals. Plus, smoothies are tasty and easy to slurp down anywhere at anytime.. I also recommend slim-fasts if you need something that will fill you up a little. Don't forget to drink a lot of water, especially if you aren't eating too much.
6. Weekends are time to EAT UP
If you can, during the weekends, try not to use your medicine.. While your loss of appetite is gone, go out and EAT LARGE.. (NOT UNHEALTHY).. I recommend something filling, but not rich.. So maybe a big sandwhich or some nachos.. Try not to eat a big steak, because it can screw up your system the second you start not eating again.. Save the steaks for holidays or special occasions where you can take multiple days (3+) off of the medicine.
7. Don't stress out
Even though you stated you were not overweight in the first place, the weight you have lost doesn't seem to be enough to HARM you.. I would stress if it get more severe than it is now. Now, remember, I am not a doctor, so I am not 100% sure if you should be worried at the moment. But I lost a lot of weight and was fine.. I can guarentee the effects will stop being so severe after taking the medicine for a while longer. I eat just as much on the medicine now as I do when I am not taking it.. Your body just needs time to overcome the lack of appetite.
All in all, I think you need to just watch your weight and see if it gets really bad.. For now, just follow my suggestions and try to get A LOOOOT of sleep.
Hope I helped,
Andrew (Anet390)
EDIT: I play soccer and the medicine has not had a negative effect on my sports skills, nor has my weight loss.. Infact, the medicine might help you make good decisions during a game.. Not sure though.