Читать книгу Why Am I So Tired?: Is your thyroid making you ill? - Литагент HarperCollins USD, Martin Budd N.D. D.O. - Страница 26

I hope now it is becoming clear that the typical low carbohydrate, calorie-controlled diet is not ideal for you to lose weight.

Glycogen loss, temporary water loss and possible unwanted loss of lean muscle tissue can occur. The blood sugar can be reduced causing the many symptoms of hypoglycaemia that dieters can experience.

Essentially dieting slows the metabolism and mentally and physically we become more lethargic. This is our body’s response to a reduced fuel supply.

To summarize, our metabolism can respond in six ways to a low calorie or low carbohydrate diet.

1 Glycogen loss occurs from muscle and liver tissue.

2 Water loss occurs.

3 Lean tissue (muscle) loss occurs.

4 Brown fat activity increases with complex carbohydrate food and decreases with high fat or protein foods

5 The metabolism slows in response to the reduced fuel obtained from food.

6 Our metabolic rate, largely controlled by the thyroid, slows down through long-term dieting.

Many chronic dieters learn to recognize that their metabolism has adjusted to their dieting. Initial weight loss is usually followed by a period of static weight, even when the same reduced calorie or carbohydrate diet is being followed. Unfortunately the return to a ‘normal’ diet for non-active dieters, often leads to a rapid return to their original weight or even to a heavier weight. Although the dieting may have ended, their new reduced metabolic rate or tempo is still operating and using calories at a slower rate. The reduction in lean body mass as a result of the dieting causes a fall in the calories used for energy and a vicious circle is established.

You may be thinking: ‘well yes, very interesting, but what about the thyroid?’. As discussed in other sections of this book, the thyroid is our metabolic clock. Therefore a metabolic slowing as a result of dieting can influence the thyroid. Conversely an existing under-active thyroid will lower metabolic activity, making dieting unsuccessful.