Daily weight fluctuations are not that uncommon, even in amounts
larger than the ones you posted. Of course much of it will relate to
the size of the person involved, which of course in this case, I do
not know. Some people's weight varies by several pounds from day to
day or even within the same day.
There are a variety of reasons this may happen.
Here are some of them. In fact the daily weight swing, more than
likely, involves a combination of them.
""Fluctuations in weight are very normal," said Thomas Wadden,
director of the University of Pennsylvania's Weight and Eating
Disorders Program. "It's important for people to realize that weight
will fluctuate as much as two to four pounds throughout the day, a
fact that can make some people freak out." -
- Quote from a health article in the Ledger Enquirer.
We need to remember the actual weight of the food we've eaten during
the previous day. For that reason, he has chosen well to weigh
himself first thing in the morning before having anything to eat or
drink. Eating before we step on the scale is no different than
putting a bunch of rocks in our pockets. The few pounds that we gain
right after a huge dinner is not fat. It?s the actual weight of
everything we've had to eat and drink. The added weight of the meal
will be gone several hours later when we've finished digesting it.
There is also the glycogen connection. There is about a 3:1 ratio of
water to carbohydrate (glycogen) in our muscle cells, so in other
words, when we lose glycogen overnight, we lose water. Even if your
friend did not go to the bathroom during the night, the minimum
figures for the body's daily water loss are 500ml through urine and
700ml through breathing and sweating. Hopefully your friend is
breathing throughout the night and one does not have to be "wet" to
demonstrate 'sweating.' We sweat constantly, even when the skin feels
dry. The dry skin means we are simply sweating at about the same rate
natural evaporation eliminates the water. It?s normal to experience
glycogen and water weight shifts of a few pounds per day even with no
changes in our calorie intake or activity level.
To break that down even more, the average amount of water loss per day
is two 8oz cups through breathing and two cups through invisible
perspiration. That is 32 liquid oz per day not accounted for in your
question. I did not include water loss from urination or bowel loss
as your question dismissed them as not important.
When you are around people is top physical condition, you will hear
them speak of daily weight swings of as much as ten pounds or more.
Here is an interesting discussion related to that:
http://forums.johnstonefitness.com/archive/index.php/t-6097.html - -
This is the John Stone Fitness Forum, one of the better such fora
Your friend is not burning off 3 - 5 pounds of fat each night. That
is impossible. But the fact that he loses 3 - 5 pounds each night is
well within the norm and there is nothing strange about it.
Search - google
Terms - daily weight fluctuations, nightly weight loss
The following websites were used to compose the answer:
"John Stone Fitness Forum"
"Why the Scale Lies" - Renee Cloe, ACE Certified Personal Trainer
http://www.holistic-online.com/Stress/stress_water.htm - "Stress
Management, water, holisticonline.com"
If I may clarify anything, please ask.