I've had this happen after post-run binges.
Assuming a healthy individual (no diabetes, etc), the body's response is called reactive hypoglycemia.
The pancreas creates a lot of insulin to handle the blood sugar surge.
The adrenal system sees this as a trigger event and ups cortisol and epinephrine (fight or flight response). At that point you can have a short euphoria or awareness boost.
Some minutes later, the insuline response is so powerful that blood sugar becomes dangerously low (hypoglycemia).
Homeostatis is disrupted for some hours, you have all the symptoms of hypoglycemia and rebound from the acute stress response. If you really ate a lot of sugar it's possible the digestive system is over its processing limit, adding bloating to the general malaise as you pass half digested food in the digestive track.