Not at all. It is impossible to melt water without using additional calories. You may use those calories to light a flame under the ice, or you may use those calories to close up some heat leaks, but you will use additional calories. A perfect thermoregulation system in which heat is directed precisely where it needs to go in order to prevent minor increases in caloric consumption is nothing more than a figment of your imagination. Such systems do not exist in the real world.
I’ve no face to save here, after all, you’re the one who flew off the handle after I introduced a few simple facts into the discussion.
This being GQ, I’m done arguing with you. It’s pointless. You will not learn.
So if I have a tin and I put a heater under it and then wait till the system reaches steady state, then put some ice in the tin, according to you it won’t melt unless I turn the heat up?
One of us won’t.
The tin will cool as the ice melts.
If you don’t want the tin to cool, you have to add more heat.
The body doesn’t like to cool below its setpoint of 37°C.
There are neuronal sensors in the hypothalamus that keep track of core temperature.
When they notice a deviation from the setpoint, they turn thermogenesis up, or down.
Here’s a little description of the setpoint mechanism.
Here’s a Wikipedia article on Fever and Pyrogens that describes all sorts of things that can go wrong with the thermoregulatory mechanism.
Does that system sound like the sort of thing that’s perfectly optimized to save every last possible kcal when a person foolishly ingests a kilogram of ice? Of course it doesn’t. What with the average metabolic rate of biochemical reactions changing by a factor of two for a 10 degree C change in temperature, there are other considerations beyond saving 116 Calories. For example, it’d be a damned shame if protein synthesis shut down just because the thermoregulatory system got stingy with the kcals.
And after the ice melts the tin will warm again. All without turning up the heater. Look, rather than go down the path of a different analogy, why don’t you attempt to say where I go wrong in my post #56?
The body or the box or the tin will cool when the ice or cold brick or whatever goes in. There’s nothing that can avoid that. Even if you burn more calories, the temp is going to drop temporarily till temperature regulation mechanisms do their stuff. The body must therefore be able to tolerate some temperature drop. Indeed if you check out **Keeve’s ** cite above, the measured temperature at various locations around the body does drop after ingestion of ice water.
The only question is whether all or most of the heat comes from burning additional calories as Cecil and others wrongly assume.
Your first cite is mostly about what triggers the body’s response to cold, not what that response may be. But from the last line (the only line where response is discussed):
My emphasis. Your second cite is about fever which necessarily involves illness and therefore is of limited relevance to consideration of what happens when you drink some ice water when healthy. But nonetheless, it contains nothing that contradicts my position and includes this:
My emphasis. What these cites make clear is that the body has two mechanisms for correcting a temperature drop. Vasoconstriction is one. Since it doesn’t involve burning additional calories, any assumption overcoming consumption of ice is going to involve a direct relationship between heat required and additional calories required to be burned is wrong.
Furthermore, neither of your cites addresses the issue of the when the body uses which strategy. I’ve already provided cites that show that the body’s first strategy, under other than cold conditions, is mostly to rely on vasoconstriction. Unless you provide cites to the contrary (and let’s face it, if you could you would have by now) you have to accept that vasoconstriction is going to be involved. And once it’s involved, Cecil and others and their simple calculation are wrong.
Exactly how many cites in support of my position do you intend to provide before you realise you’re wrong?
Does this sound like a rather desperate strawman since I’ve never said that every last possible kcal will be saved? Why yes it does.
Great Og, man. 10 degrees? You’re pretty much fricken dead if your body temp changes by 10 degrees. Let’s keep this real, shall we?
You’re not going to be able to drink an amount of ice water sufficient to represent more than a percent or two of your body weight without being sick. No doubt if you’re stupid enough you could drink enough to make yourself shiver even in a warm climate. It’s irrelevant though, because even if you do start shivering and burning more calories, you’re also going to undergo vasoconstriction, which is going to increase insulation, which is going to free up calories you would have burned anyway to warm up, which means any simple direct calculation as performed by Cecil et al is wrong, wrong, wrong.
Anything else?
How much energy does it take to constrict blood vessels in the outlying areas of the body? It seems like it must be significantly less than the energy it would take to directly warm the body back up to its equilibrium point (i.e., the amount of energy it would take to raise the ice water to body temperature), or the body wouldn’t utilize it as the first strategy for bringing the temperature back up, right?
Sounds right to me. For all that people seem to recite this notion that the amount of energy it might take to close some valves is worth talking about, I’ve never seen a cite to suggest it’s at a level that’s even measureable.
First I’d like to say (again) that Princhester is my hero.
Second, I’d like to laugh at the mess I’ve started, and some of the people who are clinging to an obviously incorrect conclusion.
I love the analogies - the Car analogy, the fire in the living room analogy. . . great ways to explain to some of these amazing people something that you’ve already been over ten times! I had a hunch when I made the post - but am glad that I now have a cited answer that the ice diet will not work!
One silly question though:
Should we conceed that the (very few) calories required to perform vasoconstriction would actually cause you to burn (a tiny amount) more food calories when you eat ice?
Could we diet by drinking hot and cold liquids in an alternating pattern. . . effectively excersizing our vasoconstrictor muscles?
(Ok that was two related questions)
I repeat, you cannot melt ice for free.
Princhester’s little model in post #64 describes the thermal response of a lizard on a warm rock, which suddenly finds itself with ice in its belly.
All warm blooded creatures, including you and I, take a more proactive approach to thermal challenges. We close up our capillaries, we turn up non-shivering thermogenesis[sup][/sup].
That all takes calories that we would not have used had we refrained from eating ice.
I’m done arguing science with lawyers, so if you choose to believe bullshit, you’re welcome to it. The facts do not care what anyone believes.
[sup][/sup] Wikepedia’s article on thermogenesis gives short shrift to non-shivering thermogenesis in adults with its claim that “Non-shivering thermogenesis usually occurs in brown adipose tissue (brown fat)”. The fact is even adults with no brown fat produce a lot of heat through non-shivering thermogenesis.
As I linked previously:
See that bit about energy expenditure increasing significantly when a person is placed in the cold, and how it’s not due to fidgeting or shivering? That’s the contribution of non-brown fat-non-shivering thermogenesis. As the authors of the article freely admit, and as I alluded to earler in post #36, the mechanism of non-shivering thermogenesis in adult humans is not understood. It is known that it can really burn through the Calories.
Agreed. The point I made at the outset was however that closing up capilliaries was the number one strategy unless already cold.
Three points.
Firstly, while you cling to the notion that just closing up capilliaries will of itself burn calories, let me ask for about the third time for cite that this is significant. Why you keep saying this, over and over uncited despite demand, in GQ, is an issue for the mods or for the general standards of the boards in general perhaps, but takes the debate nowhere. Your constant assertion of this point is just noise. Put up or stop wasting electrons.
Secondly, once you accept that some of the calories used to warm the water are going to come from conservation of calories (by vasoconstriction) that would have been burned anyway any direct calculation as employed by Cecil et al is wrong and that’s always been my major point.
Thirdly:
Yes I do see that. I also see that the experiment in question was done by reducing environmental temperature to a level specifically designed to be too cool, ie 17C because the experimenters were deliberately trying to induce heat producing activity. I accepted right from my very first post in this thread that the major fallacy in the whole ice diet concept was that it wouldn’t work unless you were already cold. I also mentioned that the turning point (based on the cite linked from my first post) was 20C. Above that, when you are at a comfortable shell temperature, it seems to be vasoconstriction that is the major applied stategy. So thanks, once again, for the cite supporting my position.
Upthread, someone referred to the link from my first post in this thread as “Princhester’s link”. Well, they may have named it after a lawyer but it’s a link to a paper by a scientist. And the link says, once again:
I really think, Squink you need to read that. Then read it again. Then perhaps read it a few more times. And then go away.