[petelamana (OP)]

I have noticed that the best time of the day for me to lose weight is when I'm asleep.  Why?  Over a typical night I'll drop between 2 - 4 pounds.  I even tried fasting, thinking that the reason might be because I may graze-eat during the day.  However, even after a complete day of no food intake, and only little water, I still noticed that my -Δweight is greatest at night when I sleep.

Porque?

[Colin2B]

Restless sleeper?
Most people burn abt 500C overnight, nowhere near enough. Sleeping in a cold room helps with weight loss but only longer term. Water loss is most obvious culprit, but I assume you don’t wake bathed in sweat.
I assume you weigh yourself before going to bathroom.

Any teeth marks on your neck that you would like to tell us about? Strange visitor who insists on sleeping in the cellar?

[petelamana (OP)]

LOL. 

No, no bite marks. Darn.

I am not generally a restless sleeper, and my dog, who sleeps with me, gets up more than I do to relieve himself.  It's the strangest thing.  For example, last night I went to bed weighing 244.8 pounds, and this morning I rose, relieved, and then weighed in at 241.2.  Don't get me wrong, I am overjoyed with the loss of weight.  I was simply curious as to why such an event happens.  I happens EVERY night.  Besides watching my diet and calorie intake, I have dropped nearly 70 pounds since the end of August.  I feel great.  It's just weird.

[chiralSPO]

Besides watching my diet and calorie intake, I have dropped nearly 70 pounds since the end of August.  I feel great.  It's just weird.

Losing 70 pounds in six months without trying sounds somewhat alarming to me. You may want to get your thyroid checked. My father in law felt "great" and "energized" for a year, and lost nearly 100 pounds in that year without making an effort. It turned out his thyroid was way out of whack, producing too much thyroxine, and he needed to get it killed with radioactive iodine because it was also affecting his heart.

Don't freak out, but also don't ignore sudden changes in your body.

Regarding the timing of the weight loss:

For example, last night I went to bed weighing 244.8 pounds, and this morning I rose, relieved, and then weighed in at 241.2.

Are you weighing yourself right after "relieving" yourself in the evening too? If not, that is almost certainly the culprit. 2 lbs sounds about right for "a tinkle and a plop" (that's very specific scientific terminology, right there!)  or just a tinkle after a night of drinking...

Even if you are weighing yourself immediately after having made your sacrifice to the porcelain alter in both the evening and morning weigh-ins, the difference may also lie in the fact that presumably you are weighing yourself after dinner and before breakfast?

[petelamana (OP)]

Thank you for your concerned recommendation.  I see my doctor next month, for a check, and I'm sure we will discuss my weight loss.

I weigh myself, in the evening, after a "tinkle and a plop" - right before I jump into bed, and again in the morning, after I "reacquaint myself with the porcelain throne", and before I eat anything.

There is another change... I only eat when I'm hungry.  If I'm not hungry, I don't eat.  I, also, only eat until I am no-longer hungry.  I through a half of an apple out for the animals the other day because I was no-longer hungry.

[Colin2B]

70lb?? That’s abt 30kg half my bodyweight. I wouldnt be waiting for a checkup.
On the odd occasions i have begun to feel a little flabby i never try to correct more than 0.5 to 1kg/week. More than that risks health problems.
It sounds as though you are continuously losing weight but the daytime input is masking it.
Have you tried tracking your calorie intake?

There is another change... I only eat when I'm hungry.  If I'm not hungry, I don't eat.  I, also, only eat until I am no-longer hungry.

Me too, but i rarely miss a meal. If im hungry between meals i have some nuts or fruit.

Might be worth bringing the checkup fwd, we are only 1/2 through the month. Might be nothing, but it’s always worth taking note of changes.

[evan_au]

There is another source of lost weight overnight - breathing.

Our metabolism continues overnight, but at a reduced rate.

Metabolism means burning sugars or fat to carbon dioxide, which is exhaled, and water, which is mostly exhaled, with some retained in the bladder.

In emergency situations, your body can also break down proteins as well - not a good place to be for long periods of time!

See: Dr Karl's "What's the story with fat?"
http://www.abc.net.au/science/articles/2015/02/03/4171365.htm