GI Diet (Glycaemic Index) description and reviews

GI Diet (Glycaemic Index)

What is the GI Diet (Glycaemic Index)

In 1981, professor of nutrition Dr David Jenkins was looking at how different carbohydrate-rich foods affected blood sugar levels in people with diabetes and discovered that, contrary to popular belief, many starchy foods affected blood sugar levels quite dramatically, while some sugary foods had little effect. From his research, he developed a scale called the Glycaemic Index, which quite simply ranked foods based on the effect they had on blood sugar levels.

The Glycaemic Index runs from 0 to 100 and usually uses glucose - which has a GI value of 100 - as the reference. The effect other foods have on blood sugar levels are then compared with this. In simple terms, the GI index tells us whether a food raises blood sugar levels dramatically, moderately or a little bit. Foods that have only a slow, small effect on blood sugar have a low GI value, while those causing a rapid and massive rise in blood sugar have a high GI value.

Glycaemic Index and Weight Loss
The theory behind diets based on the Glycaemic Index is that foods with a low GI value slowly release sugar into the blood, providing you with a steady supply of energy, leaving you feeling satisfied longer so that you're less likely to snack. In contrast, foods with a high GI value cause a rapid - but short-lived - rise in blood sugar. This leaves you lacking in energy and feeling hungry within a short time, with the result that you end up reaching for a snack. If this pattern is frequently repeated, you're likely to gain weight as a result of constantly overeating.

Diets based on GI index simply encourage you to eat plenty of foods with a low GI value and avoid those with a high GI value. This helps to prevent swings in blood sugar, helping you feel fuller for longer. However, most GI diets also recommend cutting down on fat, especially saturates. This means many of the foods which have a low GI value but are high in fat - whole milk, crisps and chocolate, for example - are still limited.

Glycaemic Index Tables

Table 1 - Low GI Foods

Food	GI
Roasted and salted peanuts	14
Low-fat yoghurt with sweetener	14
Cherries	22
Grapefruit	25
Pearl barley	25
Red lentils	26
Whole milk	27
Dried apricots	31
Butter beans	31
Fettucine pasta	32
Skimmed milk	32
Low-fat fruit yoghurt	33
Wholemeal spaghetti	37
Apples	38
Pears	38
Tomato soup, canned	38
Apple juice, unsweetened	40
Noodles	40
White spaghetti	41
All Bran	42
Chick peas, canned	42
Peaches	42
Porridge made with water	42
Lentil soup	44
Oranges	44
Macaroni	45
Green grapes	46
Orange juice	46
Peas	48
Baked beans in tomato sauce	48
Carrots, boiled	49
Milk chocolate	49
Kiwi fruit	52
Stoneground wholemeal bread	53
Crisps	54
Special K	54
Banana	55
Raw oatbran	55
Sweetcorn	55

Table 2 - Moderate GI Foods

Food	GI
Muesli, non toasted	56
Boiled potatoes	56
Sultanas	56
Pitta bread	57
Basmati Rice	58
Honey	58
Digestive biscuit	59
Cheese and tomato pizza	60
Ice cream	61
New potatoes	62
Coca cola	63
Apricots, canned in syrup	64
Raisins	64
Shortbread biscuit	64
Couscous	65
Rye bread	65
Pineapple, fresh	66
Cantaloupe melon	67
Croissant	67
Shredded wheat	67
Mars bar	68
Ryvita	69
Crumpet, toasted	69
Weetabix	69
Wholemeal bread	69

Table 3 - High GI Foods

Food	GI
Mashed potato	70
White bread	70
Watermelon	72
Swede	72
Bagel	72
Branflakes	74
Cheerios	74
French fries	75
Coco Pops	77
Jelly beans	80
Rice cakes	82
Rice Krispies	82
Cornflakes	84
Jacket potato	85
Puffed wheat	89
Baguette	95
Parsnips, boiled	97
White rice, steamed	98