Generally speaking, severe vomiting will not cause you significant weight loss. If you are experiencing weight loss due to severe vomiting, it is more likely that you are suffering from an eating disorder, such as bulimia nervosa.
Bulimia is a severe eating disorder in which those who suffer from it take in large quantities of food in a relatively short period of time, and then purge the food by either vomiting or by abusing laxatives and diuretics. Some bulimics, albeit a small number, will purge using fasting or extreme exercise. For bulimics, vomiting to lose weight can become an addiction. They find that vomiting after they eat becomes a form of self-comfort, and even a form of security.
One of the biggest tragedies of weight loss caused by severe vomiting due to bulimia is that the vomiting often does not produce the weight loss that the bulimic person wants it to produce. Instead, the bulimic’s body adapts to the process, and does not cause weight to drop. The bulimic then often resorts to even more outrageous attempts to purge the body of the food that the bulimic has taken in.
If you find that you are losing weight after severe vomiting, especially if you recognize that you are consciously making yourself vomit, you should contact your health care provider immediately. She may be able to refer you to a specialist who can help you adequately address your eating disorder.
Severe vomiting that is not caused by bulimia will typically not lead to weight loss. However, severe vomiting can lead to dehydration. In fact, severe vomiting can even be a side effect of dehydration, which just makes the whole situation worse. If you are unable to keep any food down due to severe vomiting, it is important that you take in plenty of clear liquids. Products with electrolytes in them, such as most sports drinks, are particularly useful when you suffer from severe vomiting. Water is another excellent choice. You should stay away from caffeinated drinks, as caffeine tends to irritate the stomach as well.