I had a total thyroidectomy a month or so ago. I was already morbidly obese but had had success in losing 2stone prior to the op. Upon leaving hospital until now, I gained 21lb, seven of which were put on in 1 week after inducing a calorie controlled diet of between 1200-1400 calories a day. I have been on Levo (175mg) and upon badgering my consultant about the weight gain, increased to 200mg for the last 4 days. Tried loads of different supplements (magnesium, selenium, krill, multivits, berocca, liquid iron). Now, some of that may be the reason for the following but thought I would post this, as since last thursday I have also started intermittent fasting. I eat nothing after about 9pm, until 1pm the following day. I don't get hooked up on calorie intake but make sure my body has at least 16 hours where it doesnt have to produce insulin in response to a food intake. Since starting this, the weight gain as stopped and I have actually lost 3lb. I am so so happy, and relieved that I appear to be back in control. I still show several hypo symptoms, ie cold hands, slow heartbeat (down to the high 40's overnight and rarely above 60 during the day at rest), tiredness etc. But at least the weight gain has stopped. I have to see if this is going to be a continuing trend, but my advice given my experience is as follows;
Don't try to fight weight gain with a severe calorie restricted diet, it will make matters worse.
Give intermittent fasting a go and see if it works for you
Take Levo away from all other meds and supplements by at least 3 hours and at the same time each day. With water, not diet sodas, milk or anything else but water.
If you like sparkling mineral water, drink this to remain hydrated and pick a brand with high mineral content, ie San Pellegrino. All mineral waters are not created equal.
Take quality supplements. Try selenium to increase T3 production & absorbtion, if you think you may have iron deficiency, take a liquid iron supplement. I also take magnesium.
Krill oil is better for reducing inflammation than Omega 3 so try this if you are prone to inflammation.
Take a good multivit.
Do not snack
Will keep the board updated on my progress but for now, this seems to be working for me and will hopefully stop the need for me to circumvent the inadequacy of the NHS by ordering in T3 from dubious sources abroad. But never say never....