VLC + Low Cal (Cron-inspired fasting) = very cold.

Normal VLC w/high fat = normal.

VLC + High Protein (PSMF) = furnace.

In my experience, anyway.

The low body temp thing is a crock and measuring it on a daily basis has zero diagnostic value in and of itself.....

But since I have done stints of VLC I'll state it has never...ever...ever....resulted in me feeling colder than those around me. I never wear a coat (mid west), and am not uncomfortable in the cold. In fact, I would say I tolerate extreme temps HEAT AND COLD better than most I know.

I've been eating VLC since January.

I have a fairly high cold tolerance--"t-shirt weather" for me starts at around 50F, and I never took my warmest coat or sweaters out of storage this past winter (I'm in Seattle, where it gets wet and chilly, but not what I'd call serious cold).

I don't know how much improved my heat tolerance will be, as it hasn't warmed up enough here to test it. But cold? Not a problem.

When calories are held constant, lowering carbs will lower blood serum levels of T3, but there is no evidence that an otherwise adequate low-carb diet will lower body temperature or basal metabolism.

In fact, the evidence we do have shows that, other things equal, basal metabolism is a function of calories, not carbohydrate.

http://wp.me/p25oah-7l

First, I have always run hotter than most people, from childhood.

My idea sleeping temp would be about 50 degrees and I have slept in temps far below that very comfortably.

I've been a low carber solidly, without breaks, since 1999. I'm maintaining a 110 total weight loss now and maintained a 90 lb weight loss from 02 -Oct 11. 5'6" 128-130lbs. I eat at a continuously ketogenic level, though over the years, I have experimented going as high as about 75gms/carbs/day, but never continuously.

Now I stay at 50 or under as it works best for me all the way around.

I basically don't cheat period, except on special occasions, and then, it will still be a low carb (no sugar etc) cheat, like a great cheesecake with an acceptable sugar sub, etc.

High fat eater.

Here's some info that explains what many if not the vast majority of weight reduced people experience.

"One of the key underlying problems is that when people lose weight, their energy expenditure does not simply fall to that of the energy expenditure of a person ‘naturally’ at that lower weight - it drops to levels far greater than expected.

Thus, a formerly-obese person burns 20% less calories than a never-obese person of that lower weight - or in other words a 200 lb person, who loses 40 lbs burns about 20% fewer calories than someone who is 160 lbs, but has never been obese. On top of this, the formerly-obese person experiences hunger, cold intolerance, and other behavioural and metabolic changes that make sustaining this lower body weight difficult.

From an evolutionary sense, this makes a lot of sense, as maintaining or ‘defending’ fat stores in the past has always been vital for human survival and therefore complex biological systems have evolved to readily take up and store excess calories when available and reduce caloric expenditure when times are tough."

http://www.drsharma.ca/obesitywhy-is-it-so-hard-to-maintain-a-reduced-body-weight.html

Given the fact that I seem to have been born quite remarkably heat intolerant, I believe that has served as a protective factor for me. As well, my protein and especially fat intake are probably also significant factors.