Can you lose eight pounds in one day?

No matter how you look at it, losing 8 pounds in one day involves a trip to the hospital followed by a recovery period.

The healthiest option involves a surgical procedure called liposuction, in which some of your body's fat is literally sucked out of you.

The next most likely scenario involves the loss of a limb; but it's unlikely that this was something you were considering.

Finally, if you try to lose that much weight in one day by fasting and exercising aggressively, you're going to dangerously dehydrate your body, possibly give yourself heat exhaustion, and maybe even trigger a heart attack.

The smallest time period over which it's reasonably safe to lose that much weight is about two weeks; and almost any doctor would tell you that a month is better.

So in the spirit in which you asked the question, the common-sense answer is no.