False dichotomies: cot'd.

I'm talking about the "What causes Z, X or Y?" & "What is best, X or Y" type statements.

From http://johnbarban.com/fitness-vs-fatness-a-false-dichotomy/

Some people believe that hormonal disruption causes obesity, rather than energy excess. The vast majority of people who are overweight or obese weren't born with hormonal disruption. It's years of chronic energy excess (see Determinants of the Variability in Human Body-fat Percentage for the many reasons causing it) that make people too heavy/fat than is healthy. Once too heavy/fat than is healthy, various hormones become disrupted, causing even more energy excess. Therefore, the cause of obesity is not one thing or another, it's both (plus lots of others), which is why reversing it is so difficult.

On Peter D's blog, the title reads "You need to get calories from somewhere, should it be from carbohydrate or fat?" I say "Both. And some protein. And a bit of alcohol, too!" And I know that I shouldn't start sentences with And.

It's been a while since I posted a video of me singing. Here's one from February this year.

Taking levothyroxine & overheating in hot weather - the penny drops.

Last night, I was sitting in a hot stuffy pub listening to some excellent music being played at a jam session. During the breaks (when it was quiet enough to hold a conversation), I was chatting with Jack the Rapper. As I was chatting, a thought popped into my head about why I was dripping with sweat, when everyone else in the audience wasn't. Here it is.

The Hypothalamus secretes TRH (Thyrotropin Releasing Hormone) which reaches the Pituitary via the hypophyseal duct.

The Hypothalamic Pituitary Thyroid Axis (HPTA) regulates body temperature. It varies thyroid hormone levels (T4 & T3) which varies Uncoupling Protein (UCP) expression, which varies heat production, which varies body temperature. See Minimal changes in environmental temperature result in a significant increase in energy expenditure and changes in the hormonal homeostasis in healthy adults.

"Thyroid hormones axis Compared with exposure to 24 °C, exposure to 19 °C resulted in small, non-significant increases in total triiodothyronine (T₃) and TSH AUCs and a significant increase in serum free thyroxine (T₄; P=0.03). When the analysis was performed according to the gender, a small but significant increase in serum T₃ AUC was observed in males (P < 0.05) but not in females. Similarly, while the change in free T₄ was highly significant in males (P < 0.002), no significant change was observed in females." Is this why women feel the cold more than men?

My Pituitary doesn't secrete Thyrotropin a.k.a. Thyroid Stimulating Hormone (TSH), so I'm prescribed levothyroxine 125μg/day every day. When the ambient temperature rises, my HPTA doesn't lower my thyroid hormone level as I am running "open-loop". My UCP produces too much heat which makes me overheat. Ker-ching!

From now on, I will adjust my levothyroxine dose to a value where I feel comfortably warm at all times. According to http://www.drugs.com/pro/levothyroxine.html, the half-life of levothyroxine is 6-7 days. Any change in levothyroxine dose will take about a week to get half-way to its final effect on internal heat generation. This could take quite some time!

Continued on Taking levothyroxine & overheating in hot weather - the penny bounces back up.