Dr Atticus' Miracle Ice-Cube Diet!

[Blake]

@John Mace

I don’t know. You made the original claim, so I’ll just say: cite? If you’ve got one, fine. It’s not intuitively true, though.

"This study determined the influence of water temperature and swimming velocity on sweat loss and body temperature during swimming. Trained male college swimmers (N = 5) swam 1,500-m freestyle at three submaximal velocities (90, 95, and 97.5% of best performance) in water temperatures of 26.4 and 29.2 degrees Celsius.

Heart rate, RPE, and body temperature increased significantly in relation to swimming velocity."
http://www-rohan.sdsu.edu/dept/coachsci/csa/vol72/taimura1.htm
I have no idea why you think this is intuitivley not true. Anyone who has ever climbed out of warm water after a vigorous swimming session knows they they will be sweating. Quite obviously core tempertaure had been elevated by the swimming and the body has been making efforts to keep it down.

[Rhubarb]

@Blake

OK, I’m going to need to see some strong evidence to believe that for even one moment.

Low temperatures certainly stimulate appetite, which may lead to a weight gain, but that has nothing whatsoever to do with adding subcutaneous fat to protect the body. The fat itself is laid down in perfectly normal patterns AFAIK, not in any manner that would aid temperature regulation. All else aside human subcutaneous fat is almost as well supplied with blood vessels as the skin, and those vessels are harder to regulate. As a result human fat has almost no insulative properties.

Okay, you forced me to do some research, but from multiple sources, subcutaneous fat is a considerable component in preserving core temperature. From this NASA paper (Warning! - large pdf file);

The subcutaneous fat layer provides the extra insulation that substantially reduces heat loss from the body, extends body core cooling, and hence extends the thermal drive for metabolic responses to cold.

Also, extra fat results in lower heat loss per volume of mass by increasing the surface area to volume ratio.
As far as the body adapting to cold by adding fat, the information I found is not as clear. I based my original claims on the body’s more general responses to external influences, i.e., formation of callus from persistent irritation, strengthening of bone and muscle tissue from repeated stress (exercise), darkening of the skin from UV exposure, thickening of hair and nails from stress, etc. I extended this reasoning to fat production in humans based on Nature’s use of this device in other animals such as polar bears, seals, some birds, etc. I was willing to concede that I didn’t have a cite and had merely reasoned this out, but the same NASA paper offers this bit of support;

Members of polar expeditions usually develop a thicker layer of subcutaneous fat in winter than in summer (Zeisberger and Briick, 1976). However, this change is more likely caused by some factors other than cold exposure, for example, less physical activity or a modified diet, and as such cannot be considered an indicator of cold-adaptation; nonetheless, its consequence is an increased tolerance of cold. So far, the only example of a preferential laying down of a substantial amount of subcutaneous fat that can be directly related to cold acclimatization is the channel swimmers (Pugh and Edholm, 1955).

Emphasis mine. This would seem to indicate that repeated immersion in cold water does cause an increase in subcutaneous fat.

@Blake

The second problem is that the body responds to changes in temperature, not to absolute temperature, hence people in the tropics experience the same increase in appetite in winter as people in Canada, even though a tropical winter is warmer than most Canadian summers.

I’d like to see a cite for this. I lived in the tropics for two years. There was no winter. I was as likely to be at the beach in February as I was in July. Most homes didn’t have air conditioning, but NONE of them had heating.

[Rhubarb]

Another bit from the NASA study;

Because of some extra fat that they usually have, women would be expected to survive longer in
cold water than men. Swimmers, particularly channel swimmers, who endure long periods in cold water
usually weigh more than other athletes of similar height and age because a higher percentage of their body
weight consists of fat (Pugh and Edholm, 1955).
There are suggestions that the insulative layer of subcutaneous body fat develops as an adaptation to
frequent and prolonged immersions in cold water. However, it does not seem to be a general phenomenon.
The Korean amas, who make their living by regularly entering cold water, have less fat than
other Korean women and much less fat than American women (Keatinge, 1967).

While this may not be the “strong evidence” you requested, it is in support my claim unless you are a Korean amas, who are apparently quite lean by nature.

[Rhubarb]

Still waiting on a response from Blake. I’d also like to see a cite from him/her regarding increased winter appetites in the tropics.