Fatigue or tiredness is a common symptom that has many causes. It can
result from illness, stress or lack of sleep. One of the most common
causes of fatigue is anemia, which results from a reduced capacity to
deliver oxygen to the tissues. It often occurs as a result of chronic
illness, but it can also be due to a faulty diet.
The most common form of anemia to affect women is caused by iron
deficiency, as a result of poor diet, blood loss or illness. The main
source of iron in the diet is meat, especially liver. Non-meat sources
for vegetarians and vegans include beans, lentils, dark green leafy
vegetables, nuts, wheatgerm and sunflower seeds. However, some people
with anemia - mainly women - often need iron supplements and not just
food sources of iron.
Two other nutrients, vitamin B12 and folate, are also needed for blood
formation. Folate is found in wholegrain cereals, liver, dark green
leafy vegetables and nuts. Vitamin B12 is found in meat, fish, eggs and
dairy foods, so may be lacking in vegetarian and vegan diets. Some
studies have found that vitamin B12, when given by injection, can
decrease tiredness.
Diets that are high in refined carbohydrates or low in calories, iron
or zinc can also cause fatigue. Refined sugar and readily digested
starches (which are found in confectionery, biscuits, cakes and
pastries) give you a sudden surge of energy because they reach the
bloodstream quickly. In susceptible people, blood sugar (glucose)
levels then tumble about half an hour later with a resulting feeling of
tiredness. Long gaps between meals can also cause low blood sugar
levels, so try to eat regular healthy snacks such as fresh fruit or a
packet of nuts and raisins.
You can help to keep blood sugar levels on an even keel by cutting down
on refined sugar, and getting into the habit of eating little and often
- four to six small meals a day, Complex carbohydrates such as bread
made from wholemeal flour, oat-based products and cooked pulses provide
a much slower, steadier release of energy.
People who are crash-dieting will not be taking in enough calories to
sustain their body's normal functions, and will tend to lack energy.
Crash diets are ill advised - it is better to lose weight slowly and
surely - about 0.5-1kg (1-2lb) a week - by cutting down on fat. A gram
of fat contains twice as many calories as a gram of protein or
carbohydrates. To lose weight without fatigue, replace fatty foods with
carbohydrates, such as fruits, bread, pasta and oat-based foods.
Zinc is essential to many of the body's enzymes, so it is vital for
energy metabolism. Good sources are red meat and seafood - especially
oysters.
While alcohol may seem like a good pick-me-up after a hard day, it
causes fatigue and so makes you feel worse rather than better.
Stimulants
Caffeine in tea, coffee and colas brings short-term relief from
fatigue, but an excessive amount (more than six cups a day) may well
leave you feeling tired.
Other Causes
The underlying causes of prolonged fatigue can range from physical
illnesses such as Glandular Fever and Myalgic Encephalomyelitis, now
more commonly called Chronic Fatigue Syndrome, through to psychological
conditions such as stress and depression. A lack of stress or
stimulation can also cause fatigue.
Lack of exercise can be another cause of fatigue. This is because
taking regular exercise will increase the oxygen storage capacity of
the muscles and stimulate the immune system. It may be the last thigh
you feel like doing when you are tired, but exercise should leave you
feeling invigorated!
