The purpose of eating is to fuel your body ...not to force your self to throw up afterwards. You should probably get some help for your eating disorder, you're hurting yourself.
if i dont throw up right after eating, ie i throw up at night time after a day of eating, do i still gain all the calories of the food i've eaten?
If you continually force yourself to throw up, you will do serious damage to your body. Many people have died from doing this. Your esophagus is not designed to handle stomach acid and will rot away. Once it does the stomach acid then can get to the heart and lungs. Once it reaches you heart you are dead. DO NOT FORCE YOURSELF TO THROW UP AFTER EATING!
your body absorbs the calories within a couple of hours after you eat. Throwing up several hours after you eat does nothing. I have a throw up habit as well (it feels normal for me to do so but i usually do it within minutes after a meal) i don't throw up all of my meals. Just mainly dinner.
No. It is unhealthy and can lead to diabetes, high blood pressure, heart disease, and a number of other maladies. It can also take a heavy emotional toll. Take Action Now! The first step is to admit to yourself that you have a problem. If you are a religious person, pray to God about your plight. Implore him for insight as to what is behind your disorder so that you can conquer it. Third, talk to a parent or other adult who is in a position to help you. Caring adults will not shame you. Admittedly, the road to recovery is not easy. In some cases professional assistance is needed. The important thing is to take action. That’s what one girl resolved to do. “One day,” she says, “I began to realize that purging was actually controlling me. Yet I wasn’t sure I could stop. Finally, I did the hardest thing I’ve ever had to do. I asked for help.” You can do the same!
Yes, you will gain most of the calories after that length of time. But you are also damaging your digestive system and could ultimately die from this behavior. Please stop it.
Please forgive a dumb question, but I am severely confused.
Why eat if you plan to vomit the food back out? I will not comment on bulimia because that is between you and your parents/counselor/therapist.
Different types of food (protein, carbohydrates, fat, minerals, vitamins) are absorbed at different parts of the digestive track. According to http://arbl.cvmbs.colostate.edu/hbooks/pathphys/digestion/basics/transit.html, for the average human, it takes 2.5 to 3 hours for 50% of food ingested to leave the stomach and 4-5 for it to become empty. Further it takes 2.5-3 hours for 50% of food to have left the small intestine and moved on to the large intestine. They provide no number for all food to have passed through the small intestine. Please remember those times are averages, there is a LOT of variation from those averages by people. If you are truly curious, you could probably find a doctor that will do tests to find your actual speed of digestion.
It has been a very long time since I read about digestion. I know that simple carbohydrates begin absorption in the mouth. So you sugars, chips, corn, ... Begin absorption there. However few of us chew our food long enough and well enough to have significant breakdown of carbohydrates and absorption there. Mostly we swallow large chunks and digestion and absorption stops until the small intestine is reached. We begin digestion of proteins in the stomach but no absorption begins until the small intestine. Fats begin digestion in the mouth but very little occurs there. Basically fats form hydrophobic spheres of fat surrounded by water. These spheres and chunks of fat do not really begin digestion until mixed with bile and becoming emulsified (much like if you have a lot of grease in a skillet and add detergent, it suddenly becomes a solution with water instead of areas of fat and areas of water). The emulsification allows the fat to become individual molecules that can be broken down and absorbed in the small intestine or sometimes just absorbed.
From this information I would guess that it takes for most of us a good 8 hours for most of our food to be absorbed.
Assuming your rate of digestion, gastrointestinal motive action, nad rate of absorption are right on the average for humans the following should give some data like you requested. When you undergo forced vomiting in less than an hour you have lost most of the food before it can be absorbed, maybe 10-15% at BEST has been digested and absorbed, I suspect the number is closer to 1-5%. If you vomit after 5 hours you are still losing over 50% of the food you ate. You have not probably finished digestion and absorption until 8-10 hours.
Remember vomiting not only vacates the material in the stomach but much if not most in the small intestine too. (The foul smell and taste of vomit is from the bile mixed in with the food. If only the stomach is evacuated it will be a sour burning taste - or that is what my gastric reflux at night tastes/feels like.)
So again, I ask why eat the food to start with. Depending on how soon after you eat you vomit, you may as well have not eaten at all plus the gastric fluids are damaging you throat, mouth, and teeth, plus you must suffer through the process and have the bad taste in your mouth and bad breath until you can brush.
If this is indeed a regular behavior, I would suggest seeing someone about it. You may very well drive away boys that would otherwise be attracted to you as well as possibly driving away those friends that care the most about you (and those are your true friends). If this is about losing weight, trust me someone that only sees your outside is not worth knowing. The only people worth knowing or calling friends are those that see your inside and still accept and love you.