Does your teen forget to eat? Not want to stop what she's doing? While adults can often miss meals or restrict their eating and just feel hungry, teens have far faster metabolisms and fewer reserves. Let's look at what happens when a busy or picky eater skips a few meals or eats a cookie and moves on.
Normally, part of our food digested goes into short term storage (glycogen) and long term storage (fat). Through the night or at points throughout the day when we need fuel, our liver releases glycogen into our blood to keep our blood sugar in the normal range.
Once the liver is out of glycogen, it gets more complicated. Glycogen can be mobilized from other parts of the body. like the muscles, which will make us feel weak, like we just worked out, even if we didn't. Fat can be burned for energy, assuming your body can switch gears into fat burning as primary fuel instead of background fuel.
The ability to use fat as primary fuel seems to depend on the person - individual metabolism, experience using fat, and of course fat reserves.
So let's say you have a skinny teenager who eats candy or bread when she does eat. She may rarely eat extra calories, and most goes for immediate fuel. What little is stored gets used up overnight and in the course of the next morning when she skips breakfast. If she also skips lunch, or eats a small lunch, she may experience shaking, fatigue, a headache, or all three. Her body is pumping out cortisol to keep her going, with little fuel available, and blood sugar is going to be very low. Emotions can start to go nuts, from angry to weepy.
If this sounds like your teen, if you pick her up from school and she falls apart in the car, if she can't finish a test or assignment without panicking, she may be experiencing extreme lows due to the limited food intake and fast metabolism. Here are some tactics to get her blood sugar up so she can rejoin the land of reason:
1) Offer sugar first. I know this sounds terrible, and it's not an ideal precedent, but just as with diabetics, the fast solution for low blood sugar is sugar. This is not the time to eat that wholesome low glycemic meal if the teen is begging for a donut or crying in the backseat of the car. Get her something with lots of carbs, even soda or juice, and a big serving of water, since dehydration helps no one.
2) Follow the sugar with a real meal or big snack. Again, not going for perfection, just calories. A drive through is probably better than nothing if you have a 30 minute ride home and a kid crying in the back. Or you can bring something for her to eat in the car that has protein, fat, and carbs - trail mix, a sandwich from home, apple and peanut butter, larabars, beef jerky. Just buy a few things to have on hand and offer, and sidestep the insanity.
3) In the long term, slow down, cook her food, and find new favorites. Teens can be too preoccupied with feelings and busy schedules to plan a meal or snack , or even eat what seems obvious to an adult. Offering to cook something has been a big help towards getting my teen eating more and better. She feels loved and she eats more and enjoys not doing to prep herself. (My stipulation is generally that she be doing school or helping out while I cook.)
While I still feel that teens are picky, and there's a character question to be tackled, soon enough they will be buying their own food in college or living on their own. So paying more for new foods that she might enjoy, to broaden her ideas before she pays the bills, can help her develop good habits and experience how much better she feels eating well and eating enough.