Now, the cause of chronic fatigue could be one or a combination of several factors listed below.

Hormonal problems

Sugar imbalance

The foods you eat

The environment, especially the air you breathe

Moulds, mites, allergies

Sleep and relaxation

Exercise

Depression

Dr Ronald L. Hoffman in his book Tired All The Time (Poseiden Press, 1993) discusses these factors at length. But then he comes out with a few surprising findings about chronic fatigue — secrets that fly in the face of some of our conventional wisdom.

His first and most important finding: Energy begets energy. There are people who attack their day with a gusto that seems to increase with each passing hour. They appear to be made of different stuff from ordinary persons. But they’re not. People who put in tremendous energy are energised by their very activity. Physical activity oxygenates all parts of the body, including the brain. The result: more energy. According to Hoffman, once you’ve corrected any flaws in your lifestyle or diet or environment that may be contributing to your fatigue, then you’ll find that energy begets energy.

His second finding: Life is not a steady downhill process. While a certain decline in vitality is a natural consequence of ageing, your energy quotient can be sustained at high levels well through middle age and into your senior years.

His third finding: Efforts to conserve energy can leave you more exhausted. Most people think resting a lot will cure their fatigue — yet it often makes it worse. Someone asking another to post a letter a few blocks away, because of being too tired to walk up to the letter box, is the most fatigued. Hoffman has even discovered that when he was tired, sleep wasn’t always the answer.

One more secret: Stimulants may give you a short-term boost, but over the long run they can deplete you. Guzzling umpteen cups of coffee can keep you alert — but leave you ultimately depleted. The body has few reserves left.

Another fact of fatigue: Fatigue can sometimes be contagious — just like a yawn. When you sit long with someone who is depressed and fatigued, you may find yourself overcome by a draining ennui.

And Hoffman cautions people who actually use sugar as medicine for the feeling of fatigue or depression. Sugar does indeed change the brain chemistry, and could impart a sense of momentary well-being. But then sugar becomes a form of addiction — somewhat akin to alcoholism. And there could be a hereditary susceptibility to sugar — love of sugar often runs in families.

Hoffman advises a switch to a diet of protein and carbohydrates, which provide the body with slowly released and steady levels of sugar, thus reducing reliance on items rich in sugar.

Here is a guide to sugar content of some common foods (grams of sugar per 100 grams of food). While raisins and dates reach 64, bananas, apricots, grapes and apples range between 16 to 12, and oranges 9. Vegetables mostly stay below 9, with onions at 5 and cabbage at 2. Jams and chocolates touch 65, ice cream 23, and Coca-Cola 11.