like-nobodysfuckingbusiness-dea asked: In your recovery meal plan thing, what's refeeding syndrome?

Basically, it happens when you’ve been severely malnourished and your body struggles to adapt to a sudden increase in calories and carbohydrates. It’s quite dangerous and it’s why people need medical supervision when they begin the process of gaining in recovery.  It’s also the reason that increasing calories by only a few hundred every few days is recommended above sudden calorie increases.

Scientifically, when you start eating more, your blood volume increases, putting strain on your heart.  Because of changes in fluid levels, your electrolytes can be thrown off, as can levels of minerals and vitamins in your blood.  Increasing calories also allows your body to speed up its systems, including the circulatory system, which means your heart works even harder.

All of this puts a ton of strain on your body and can cause a variety of very dangerous problems, and ultimately can cause heart failure.  Hospitals and treatment programs are very careful to monitor for it (symptoms include swollen ankles, changes in pulse rate).

Sorry for the long answer, I hope it made sense.