Thank you, Emmie.I'm hypothyroid (Hashimoto's), and I find all the misinformation about carbs/thyroid to be incredibly annoying.
First of all, hypo 'symptoms' can be symptoms of many, many other things in a person. No individual gets all the symptoms, and someone with an array of 'thyroid' symptoms can have a very healthy thyroid. For example, often women who are 'dieting' will suffer hair loss because they fail to eat sufficient protein. And a person who is 'tired a lot' or 'can't lose weight' doesn't necessarily have thyroid problems. If you are actually hypothyroid (thyroid isn't producing sufficient hormones), eating carbs isn't going to 'cure' you. But if you have some other dysfunction that's causing the symptoms, it's certainly possible for a dietary change to effect improvement in symptoms. [Yes, it's like putting some duct tape over the illuminated "check engine" light and thinking you have fixed the car]
Since one aspect of Hashimoto's that I suffer from is flawed conversion of T4 to T3, the notion that we need carbs for that is ludicrous. Yes. the body uses glucose during the conversion process, but that's because the body functions on glucose to maintain itself. The conversion of T4 to T3 is like any other bodily function, and the body will use part of its energy source to accomplish that conversion. No one has to eat a 'special' diet to enable the conversion.
I happen to be a person who is extremely carb sensitive, and I do best at about 20g carbs or fewer. Because of my age and metabolic situation, I also have to eat very low calorie ("low' by standard measurements, but sufficient for my own body). My endo knows this and, if fact, applauds my WOE. Since he does a full blood panel every 4 months, it's apparent that my low-carb eating is very healthy for my particular body. At age 71, the only Rx I take are my supplemental thyroid hormones. My BP and blood glucose are all excellent.