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Starches are found in foods such as potatoes, bread, rice and
pasta, they are
sometimes referred to as complex carbohydrates.
Fibre is a type of carbohydrate found in plants, but unlike
sugars and starches it is
not absorbed, so doesn’t provide a significant amount of energy. Studies
suggest that diets that include plenty of fibre, especially insoluble
fibre, may be associated with increased weight loss. High fibre foods
may help reduce appetite. This may be related to the bulky nature of
these foods, their effects on blood glucose and insulin levels due to
delayed gastric emptying or effects on gut hormones that regulate
appetite.
The recommended intake of fibre is 18g per day for adults.
Dietary Fibre exists in two main forms
Insoluble fibre is the tough, fibrous parts of the plant. Foods rich in
insoluble fibre include whole grain foods, such as whole grain and bran
cereals, wholemeal bread and pasta, brown rice and a small amount in
fruits and vegetables. Insoluble fibre is not absorbed and reaches the
large gut intact, where it has many health benefits. It can help prevent
constipation and may reduce the risk of bowel cancer.
Soluble fibre is found mostly in vegetables, especially pulses and
legumes, and in
many fruits. Oats are also a source of soluble fibre. This type of fibre
reduces blood
cholesterol levels and helps to slow the absorption of nutrients.
To increase fibre intake try:
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a high fibre breakfast cereal, such as bran flakes, shredded wheat or weetabix
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wholemeal bread
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oatcakes
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brown rice
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wholemeal pasta
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eating more vegetables at meal times
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fruit as a dessert or snack
What are whole grains?
Cereal grains such as wheat, rice, maize, oats exist in both whole-grain
and more refined forms. A whole-grain ingredient is defined as the
intact, ground, cracked or flaked grain where the main components
(endosperm, germ and bran) are present in the food in the same amounts
that occur naturally in the grain. Whole grains are healthier than
refined forms and may help to control weight. The government recommends
three 16g servings per day.
To increase your whole-grain intake try:
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whole-grain breads, biscuits and crackers
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cereals, particularly breakfast cereals labelled as whole-grain
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switching to brown pasta and rice
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whole wheat pittas as a crust for homemade pizza
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whole wheat flour for cakes and pastry
Facts about the glycaemic index
Glycaemic index is a means of classifying carbohydrates in food
according to their effects on blood sugar levels. A food that has a high
GI causes a sharp rise in blood glucose whereas a low GI food causes a
slower and more sustained increase in blood glucose.
Low GI diets are associated with a reduced risk of chronic disease,
especially type 2 diabetes and coronary heart disease. Low GI foods are
also associated with increases in fullness and decreases in hunger which
may help reduce energy intake. However claims that low GI diets can
specifically help with weight loss or weight control are premature.
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study in 2002 looked at 20 dietary trials where individuals were
randomised into a low GI or a high GI diet. Only 4 trials showed
greater weight loss on the low GI diet and in 2 of the studies
weight loss was greater on the high GI diet. The trials used only
small groups of people and were relatively short in duration. In
addition, the low GI diets tended to have a lower energy density and
higher fibre content than the high GI diets, which helps to explain
any weight loss.
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To lower the GI of your diet try:
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porridge for breakfast
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lower GI breads such as rye bread
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adding pulses such as lentils and beans to savoury dishes
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long grain Basmati rice instead of ordinary rice
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pasta salad in place of sandwiches
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choosing waxy new potatoes with skins in place of old, mashed potatoes
The above information comes from the Medical Research Council. Visit
their website for more information about carbohydrate research currently
underway at MRC Human Nutrition Research.
www.mrc-hnr.cam.ac.uk (click
on the 'In the News' section).
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