Log in
Thyroid UK
91,879 members106,148 posts

I was diagnosed underactive at 19 & every time I loose weight I put double back on, how do people manage this or loose weight successfully?

I am now 22 and my tablets keep getting put up. I am a fitness instructor and dance teacher so physically fit, but can't get the body I want due to underactive thyroid putting a halt on any progress. If anyone has any ideas or plans that work please get in contact

9 Replies

What dose are you on of (I assume) Levothyroxine? Do you have latest blood tests with reference ranges? You can ask your GP practice for these, then post here and people can comment. Do you feel well or still have hypo symptoms?


I'm on 150 atm, but going to have a blood test next week to retest range, getting to the point where I'm wanting to fall asleep wherever which isn't great and gaining weight even though training.


Hi You definitely need a TSH, T4 and especially Free T3 test with the ranges, ask the receptionist for them , as all Labs vary for bloods. Keep. I suspect the problem is you need some T3 too, that is especially helpful with weight.If T4 is high Over third up in range, and FT3 is low, then you need T3, regardless of the TSH( it usually goes a bit lower on T3). The GP may not see it like this, if not ask for a 3 months trial. Failing that, find a good Endo yourself and only then ask for a referral. FT3 needs to be near the top of range but, must never go over. Sometimes on T3 also with the Levo, you need slightly less Levo, depends on the tests, re test after 6 weeks too.

Best wishes,



And just to add a plea to think outside the box, E7DVL, (this is a rather inhuman name by the way!) does your thyroid problem stem from your actual thyroid gland, or is it because your pituitary gland isn't stimulating the gland with enough TSH? If it's the second, then you might consider whether you're short of growth hormone and/or cortisol. I have a friend who has struggled throughout her life with her weight, which she was told was due to her thyroid. But in fact she has recently been diagnosed with hypopituitarism (which the low thyroid was part of), and is taking growth hormone now, and at last her weight is under control. Anyway, whatever, I'm sure that the advice you get on this site will cover all the possibilities.


This is an archived link which may give some scientific explanations. Some links within may not work.



Even apart from thyroid issues, dieting DOES this... rebound weight gain after loss is almost universal, whether or not it is related to Reverse T3 formation, or any of the other ideas I have heard suggested over the years causes it; it happens :-(

The one benefit you have is being 22, the cycle of loss & gain hasn't had much time to get really severe yet.

Low calorie/low fat diets simply do not work.

I am far from the only person to experience this... illustrated by many family members and plenty of friends and acquaintances too - but every time I used one, (and I have used MANY, including as low as 600 calories per day!) I ended up fatter at the end of a short period after eating even remotely "normal." Increased exercise reduces this effect, but does not get rid of it totally. Even when seriously weight/fitness training for some years, this still happened to me.

In fact I would go further and suggest that with a hypothyroid condition it is is even worse, the loss of nutrition it results in compounds the matter.

The only sustained long term weight loss I have achieved has been by eating low carb (personally I prefer low glycaemic Load). Currently 53kg loss - ZERO increased exercise due to long term disability & severe chronic pain. I probably eat more calories now than at any point in my 55 years too, don't count them so not sure how many, but I now eat penty of fat, but not even remotely hungry either... although that is not to say it isn't hard, as it is a very different way of eating. Cholesterol levels are much improved too :-)


You are on a low carb diet, are you talking about one like the Atkins diet?? or could you give me an idea of what you do eat..I was asked to leave weight watchers and others because the only thing I managed was to put on weight and then some..I am now 4 stone heavier than when I was diagnosed with underactive thyroid and cant find a good eating plan, All diets have more food in them than I am used to and I am struggling!! I would value your input.


As a personal trainer and dancer I eat clean, so i definitely don't do fad diets, this is why it is so frustrating when I eat so well and train that I gain weight. I'm 40% muscle which obviously creates a heavier mass, but I can't decrease the body fat.

I have been back and forth to the doctors trying to get it sorted but each time they just but the levo tablets up but not really finding out more. I think it's time to get some more answers.

Thank you for your replies :) x


I know how frustrated you must be feeling, before being diagnosed with UAT I was exercising regularly, doing high impact aerobics twice weekly and running 3 x weekly and still gaining weight. Went to my GP, and after some prompting checked my TSH. I was put on 100mcg of thyroxine a week later, but still gained weight over the years, as thyroxine really didn't help, still had many of the common symptoms. This year I have started intermittent fasting, I fast twice weekly and have lost 16lbs, I know this might not suit you but I have found it an easy way of losing some weight, look into it, you can go onto the web site, just type in 5:2 or intermittent fasting and you should get all the info you need. Good luck x


You may also like...