Those who fast on Yom Kippur are familiar with the discomfort associated with depriving themselves of food and drink – to say nothing of a nice, hot shower – especially during the last leg of the 25-hour fast.

Marni Wasserman, a certified natural chef and a culinary holistic nutritionist, spoke to The CJN about the effects that a 25-hour fast can have on a typical healthy adult.

She says the first eight to 10 hours should pass without any physical discomfort. “They’ll go to sleep, wake up, but then, normally, people’s bodies are gearing up for breakfast or coffee or whatever their morning routine is.”

That’s when the problems start.

Let’s take a closer look at how different parts of the body react to going a full day without food and water.