The FastDay Forum

My thyroid has been under the optimum range for a couple of years now and I am to have it retested in a few months and if the results are not improved I will be started on meds for hypothyroidism. At the moment I do not have the symptoms usually associated with hypothyroidism such as great difficulty losing weight (not on this WOL any way!) but this is early days and I still have at least 2 stones to lose. I am hoping that my levels will improve over the next few months but as I have read several times on this forum that thyroid function decreases if you fast longer than 24 hours, I want to clarify something. I normally do what appears to be the most common way of fasting ie. Eat early evening normally the day before a fast and eat nothing the next day except for herbal teas, maybe miso soup in the afternoon, and then a small dinner of around 450 calories in the evening. The day after fasting I am noticing that I am more and more likely now to go without breakfast as I am just not hungry - and this is from someone who up until a few weeks ago, never missed breakfast in my life! Anyway, what I want to know is the fast considered to be over ie. when I have my small dinner of 450cals (24 hours)or am I still fasting until I start to eat normally the next day at lunchtime making the timespan approx. 30 hours? Also, does anyone know if it would be more advantageous for optimal thyroid function to have a small breakfast on the fasting day?

If you draw your fasting "boundaries" 24 hours apart then you behave differently within them and the same outside them. So if you eat normally at 6pm and draw your start line at 7pm then do as you describe the next day then after 7pm on the second day you're into "normal" routing ie sleep and have breakfast (or not) the following morning as you normally would.

What's your preferred measure of thyroid function ?

I am also interested in your question dhana because my TSH reading is 9.93 and anything more than 7 is regarded as being hypothyroid in Cyprus. I eat a low calorie meal in the evenings (less than 500 cals) because I prefer to eat my main meal at lunch time. I have only completed 4 fasts so far, and each one has been over a different period of time (eg the first fast I ate nothing from lunchtime one day until breakfast the next which was my designated fast day and then used up my 500 calories by 6pm that evening and then had nothing to eat until breakfast the following morning). I eat breakfast, lunch and dinner on fasting days, so in reality am not getting the health benefits as stated in the video and literature, but already have more energy and less inches (not weighing myself until 15 May). You will find many different options from reading the postings - and they all seem to be working!

My research drew a bit of a blank. There's a natural daily cycle of thyroid marker levels and I found a couple of studies about taking meds at bedtime rather than 30 mins before breakfast and getting better results. http://www.ncbi.nlm.nih.gov/pubmed/17201800

The top left graph below is the daily TSH pattern with the two different med timings :-

Sorry Phil the rest of us can't see that image, it is '403 Forbidden'...

this any good ?

Yes that's better thanks...

[carorees]

I've been seeing through the scientific literature on thyroid function and fasting. Most deals with longer fasts than we are talking about and there is very little recent work. However I did find some studies of interest.

This paper reports on the effects of fasting on thyroid hormones in normal weight people: http://www.ncbi.nlm.nih.gov/pubmed/6403568
This paper reports on the effects of fasting on T3 and rT3 in obese women fasting and found decreases in T3 during the first 2 days.
This paper looked at 8 healthy male volunteers fasted for 30 hours who were then given an 800 kcal dinner at 7pm: http://www.ncbi.nlm.nih.gov/pubmed/6695550 They found a decrease in TSH levels and without refeeding the nocturnal peak of the TSH was abolished. With refeeding serum TSH tended to increase towards midnight and was significantly higher than during fasting.

So the evidence appears to be that thyroid function starts decreasing fairly soon into a fast but even a relatively low calorie dinner can counteract this decrease to a great extent.

Fascinating information Caroline in both articles. I am not due for a check up for several months, but it might be worth having a series of blood tests around a fast day, just to see the changes in the TSH levels.

Will be interesting to see from the questionnaire results whether there is any correlation between rates of weight loss and fasting 'style' i.e. several meals on a fast day or just one - after discounting other factors (such as: multimeal fasters may be on average newer fasters, who will tend to lose more anyway).

From your research Caroline might we expect to find that multimeal fasters lose more weight than monomeal fasters - because their thyroid function keeps their metabolism at a higher level?

[carorees]

I suspect it'll be the other way around due to breaking out of fat burning when eating during the day, but it probably depends on what is being eaten rather than when. It's hard to guess. Let's hope we get lots of responses to the questionnaire!

[Betsysgr8]

I was diagnosed with Hashimoto's Thyroiditis with Graves Ocular something or other (my eyes bulged a bit) 19-20 years ago. This diagnosed was later changed to just Graves Disease. After a year and a half of PTU (to try and contol an out of control thyroid) I was finally able to do an uptake of Radioactive Iodine which rendered my thyroid unable to produce anymore thyroid hormones (what a relief!). Now I see my endrocrinogist every 6 months to check levels. Dosage of Levoxyl changes with weight lose/gain. I've tried generics but my body doesn't process them and my readings drop as though I hadn't taken any thyroid.
My question, do any of the thyroid discussions pertain to me?