Thyroid, Stress, LC, rT3,carb and calorie cycling
rT3 was discussed in the thread IFing and Work Outs, thought it deserved its own thread so copying some of convo from there. From about page 3:
Also wanted to mention (after watching a video from Dr Walsh), how stress and high cortisol effect thyroid function:
1) lowers TSH
2) shuts down conversion of T4 to T3
3) damages receptors on cells - doesn't allow T3 in
Last edited by Sue; 07-19-2011 at 10:23 PM.
Fasting decreases T3 and increases rT3 but normalizes after eating.
Low carb diets also decrease T3 and increase rT3, the opposite occurs with higher carb diet.
(Colpo not a fan of LC diets!)
Posted by marcadav:
From what I have read it seems diet composition, rather than decreased total calorie intake, has a bigger impact on T3. Thyroidmanager.org talks about this. And, this site provides quotes from thyroidmanager, in regards to diet, carbs and thyroid function:
T3 and rT3 greatly affected by diet... : LC Research/Media Forum : Active Low-Carber Forums
From that link posted by marcadav, some interesting comments:
Posting this for DFH on BMR I'm sure he'll agree:
“BMR: It's a magic fairy-dust number which, like "counting calories", often seems to work for fairly normal sized people with fairly normal metabolisms, but gets farther and farther from reality the larger the fat mass and/or the more deranged the metabolic state.”
“Thanks for this article, for several months my dr has wanted my rT3 levels tested and I finally broke down and got the test. I had some doubts whether this was a real problem, from what I've read I gathered it wasn't mainstream science.
What my dr told me is that T4 can convert to T3 or rT3 and that stress plays a part in what your body does. My main symptom has been that dieting doesn't work for me, one week I lose and thats it. The refeeds have been the only way I've ever lost weight. If I have high rT3 levels the solution is to stop taking any T4, only T3, so rT3 can't be made.
My dr determined possible rT3 problem by the results of my morning temperature and heartrate. They went up when I ate higher carb the previous day and decreased the day after eating LC.”
“Mary Shomon: You have said that you feel that two key hormones -- leptin and reverse T3 -- are playing a key role in regulating weight and metabolism. Can you tell us a bit about leptin, first, and what it has to do with weight loss challenges?
Kent Holtorf, MD: The hormone leptin has been found to be a major regulator of body weight and metabolism. Leptin is secreted by fat cells and the levels of leptin increase with the accumulation of fat. The increased leptin secretion that occurs with increased weight normally feeds-back to the hypothalamus as a signal that there are adequate energy (fat) stores. This stimulates the body to burn fat rather than continue to store excess fat, and stimulates thyroid releasing hormone (TRH) to increase thyroid stimulating hormone (TSH) and thyroid production.
Studies are finding, however, that the majority of overweight individuals who are having difficulty losing weight have varying degrees of leptin resistance, where leptin has a diminished ability to affect the hypothalamus and regulate metabolism. This leptin resistance results in the hypothalamus sensing starvation, so multiple mechanisms are activated to increase fat stores, as the body tries to reverse the perceived state of starvation.
The mechanisms that are activated include diminished TSH secretion, a suppressed T4 to T3 conversion, an increase in reverse T3, an increase in appetite, an increase in insulin resistance and an inhibition of lipolysis (fat breakdown).
These mechanisms may be in part due to a down-regulation of leptin receptors that occurs with a prolonged increase in leptin.
The result? Once you are overweight for an extended period of time, it becomes increasingly difficult to lose weight.”
-Quoted by Valtor
Also, women have fewer thyroid receptors than men, making them more sensitive to small decreases in serum levels of thyroid hormones.
-Quoted by Valtor
Responding to the quote above re women having fewer thyroid receptors:
“I don't think it's a coincidence that many posts by women on these forums talk about how well LC worked for them until they got within 20 pounds or so of goal, and how despite doing everything the same "with no cheats" it stopped working. The usual response here is to "lower your calories" -- and of course that is precisely the wrong thing to do.
But they do it anyway, and it doesn't work. It just makes their metabolism worse and practically ensures that they can never eat normally (1800-2500 calories a day, not starvation level 800-1200 calories a day) again. And they still can't lose those last 20 pounds!
So, can some people eat bowls of pasta a day and get neither fat nor diabetic? Sure. I'm not one of them. Can some people go to ZC, lose all the weight they want and maintain it into and past menopause? Sure. I'm not one of them.
This is the science of metabolism, not belief or anecdote or will power. I don't know if you or Deb have had your RT3 tested (and if not, would urge you to do so) -- but I have. And guess what? Eating very LC for years has given me a whopping RT3 problem. Cured my insulin resistance (another LC myth: that if you remain overweight, it's because you're still insulin resistant), so that's one metabolic problem solved -- but in the process it created another one.
Once I was diagnosed, I began to take all the steps necessary to heal it. First the inexplicable weight gain stopped. Then my temperature began to rise. From 95.5 to 98.4. My waist began to trim. My food intake rose. The final step will be to stop taking the dessicated thyroid medicine (a T4/T3 combo) and go to pure T3. My Cytomel should be here in a few weeks, and then I fully expect to start losing those last 20 pounds and to see my aberrantly high TC drop -- all while eating much, much more per day than I've ever eaten before.
Folks on these forums can argue against this idea if they wish, and continue to talk about how it's the fault of the calories, dairy, too much fat, not enough fat, wine, wheat or whatever that they think is stalling them -- but I would urge anyone reading my post or Patrick's posts to read the source material he's provided -- and then insist your doctor do a rT3 test. If it's positive (the ratio between rT3 and T3 is too low) -- insist on a prescription for Cytomel (T3), or buy it from a Mexican Pharmacy online. Treat and fix your metabolic disorder -- and the pounds will take care of themselves.”
“Well, like everything to do with metabolism it's complex. For example, there are two other things that can create a RT3 problem: low ferritin and/or very low or very high cortisol. Both problems not only stress the body in general, they stress the adrenals. You can't fully fix the RT3 problem until you find out which of the three (or some combo) of V.LC for a long time, low ferritin or the cortisol.”
“And that's because the rT3 number in and by itself doesn't mean all that much. You need to put it (once you've got it) in a ratio against your Free T3. [FT3/rT3]. If that number is under 20, you've got a rT3 problem. The lower the number is from 20, the bigger the problem. Mine is 11!
So really, there is no way to surmise the number; it needs to be obtained by a blood test and then compared to your Free T3 which should be done at the same time. Ditto for your Free T4, which should be 1.4 or under.”
Last edited by Sue; 07-19-2011 at 10:27 PM.
How stress can effect your hormones through pregnenolone steal (Dr Walsh):
Effects of Stress - Pregnenolone Steal on Vimeo