Thyroid hormones are pretty important. Especially if you are interested in being lean. Your thyroid hormones dictate how much fat you burn and and how much muscle you have. Your body can alter the amount of thyroid hormones you produce to change your metabolic rate. Cranking up cellular levels of thyroid hormones tells the cells to use energy. If the cells are fat cells they burn fat. Understanding thyroid levels is therefore important if you want to lose body fat and get lean.
Thyroid Hormone Biology
For thyroid hormones to have an effect they must get into your cells. Only thyroid hormone inside the cells can cause fat burning. Initially the body produces an inactive form of thyroid called T4. This circulates in your blood having little effect until it enters cells. Here it is converted to T3, the active form of thyroid. Only T3 can exert thyroid’s fat burning effects. In order to burn fat you need to make sure that this conversion of T4 to T3 is maintained.
‘Dieting’ Lowers Thyroid Hormones
Calorie counting doesn't work! You can't lose weight through ‘dieting’ because if you try the body will decrease the conversion of the inactive T4 to the active T3. This will lower your metabolic rate and as a result you will stop burning fat, become demotivated, feel cold and have to deal with a sluggish metabolism. A low metabolic rate also means you are much more likely to regain lost weight. This is because you need less calories and so eating ‘normally’ will now increase body fat.
Boosting Thyroid Hormones
Stress, dieting, and inflammation all decrease the conversion of T4 to T3. The opposite of what we want. Therefore we need to avoid stress, dieting and inflammation if we want to burn fat. It’s no secret that stress makes you fat. Stress causes increased belly fat and it’s very hard to lose weight if you are stressed. Inflammation is caused by stress, and is exacerbated by poor diet. The way to boost levels of active T3 is therefore to avoid stress, eat well and stop calorie counting.
Permanent Thyroid Damage
If you have undertaken periods of dieting previously you will almost certainly have damaged your T4 to T3 conversion rate. Studies suggest that even short periods of calorie restriction can cause damage to thyroid hormones lasting years. Hard to shift fat, feeling cold, fuzzy thinking and low exercise tolerance are signs that you have a damaged thyroid function. In this case continued attempts to lose weight by dieting will likely cause permanent damage. So be warned.
Eating Healthily Boost Thyroid
By having a high T4 to T3 conversion, your fat burning will take care of itself. No need to cut calories. If you have a sluggish T4 to T3 conversion, you need to redress this if you want to burn fat. However, some people will think they know best and try to force weight loss with calorie restriction despite poor thyroid status. If you try this you will have a one way ticket to weight gain on the yo yo diet express. And once the damage is done there are no refunds.