Hi! We do not have a thread on this, however, many people with hypothyroid do better on lowish carbs and higher fats. I would use the general calculations found here:

http://www.myfitnesspal.com/topics/show/819055-setting-your-calorie-and-macro-targets

but use the 'excess' calories to add more fats versus carbs. You should not need to go low carb (under 100g), but I would play around with it and see how you do on something around the low to mid 100's.

Use your actual results for the appropriate calorie target to set yourself at.

I know there is a group dedicated to Hypothyroidism. I have a friend who has it and she had to mess with her calorie goal after changing medications, but no changes on her macros.

http://www.myfitnesspal.com/groups/home/753-hypothyroidism-and-hyperthyroidism

I was diagnosed with Hashimoto's (but with a "functioning" Thyroid, so no medication) and after messing around for about 6-9 months with different macros, calorie counters, etc., to see how my body would react, I landed on the following percentages: 25% carbs, 30% protein, 45% fat (using TDEE -25% methods). I've found this mix provides the right amounts for my energy levels and needs for training, while still allowing me to lose weight. This is just one example of what you can try, and my total calorie needs might be higher or lower than what you need, but this might be a good starting point to test out. Good luck!

(edit: grammar)