Glycemic Index vs. Glycemic Load

Glycemic Index vs. Glycemic Load

Anyone who has diabetes would be well versed in the various terminology around navigating how to eat, but a lot of us are left scratching our heads over which ranking system is the right one to base our choices on. Two of the most pertinent frames of reference are glycemic index and glycemic load – both of which measure carbohydrates, but with marked differences.

Glycemic Index:

The Glycemic Index (GI) Scale indicates how quickly a carbohydrate digests and gets released as glucose into the bloodstream – measurable by our blood sugar, and how drastically it rises. The numeric scale from 0-100 grades this effect, and it is noted that cooked and processed foods generally sit at the top of the ladder, with high fat and high fibre foods at the bottom. Whilst it is preferable to eat mainly low GI foods, the limitation of this scale is that it only measures the effect of the carbohydrate on raising blood sugar levels – it fails to address a standard serving size of carbohydrates – thus making it an inaccurate measure of the real impact that a particular food will have on blood sugar levels. 

It is limited to assessing whether a food has readily available carbohydrates which can be absorbed quickly. A good example is the carrot. With a GI ranking of 71, it would seem that this humble root vegetable could raise blood sugar markedly, however, because of their water and fibre content, the actual impact that a carrot has on blood sugar is minimal – hence the very low Glycemic Load ranking of 3. In this case, if we were to use GI to influence our food choices, a whole host of health benefits could be lost – carrots are a dynamic source of anti-oxidants and minerals, and contain the potent anti-cancer substance – alpha-carotene. 

Glycemic Load:

Many doctors and dieticians feel that the Glycemic Load (GL) ranking system, is a much better yardstick by which to determine how a food will affect blood sugar and insulin levels. In comparison, the GL indicator is a measure of the amount of carbohydrates in a serving of food, making it a stronger predictor of what will happen to blood sugar. Foods which are ranked at less than 10 are considered low GL, whereas those with a value higher than 20 are considered to be high GL. The limitation of this ranking system is that eating a diet of exclusively low GL foods does not necessarily represent a nutrient dense nutrition plan. Healthy, low-GI carbohydrates do form a big portion of low-GL foods, but so too do other foods which are very high in protein or unhealthy fats. It is agreed however, that being aware of the GL of a food is a better indicator of whether the food will make blood sugar ‘spike’ which is where the danger for a diabetes patient lies – when the body has to release extra insulin to bring down blood sugar, which on a regular basis, is what leads to insulin resistance in the first place. 

Which ranking system should I use?

Used together, both ranking systems represent effective ways to select appropriate foods. If the GI system is used as it was originally intended – to choose a food in the lower GI food groups or categories, often the choice will represent a low GL food anyway. Of greater note is the glycemic response – which measures the magnitude and duration of the elevation in blood glucose concentration after eating. Interestingly, when using this system we can determine that it is healthier to eat an apple than a potato. Why? Because although both contain a similar number of carbohydrates, the glycemic index of a potato is almost double that of an apple, and the glycemic response will result in both a higher blood glucose concentration, and an elevation that lasts much longer.

Because these systems are so technical, it is useful to bring it all back to basics and consider this – when we are eating as close to nature as possible, eating ample good fats, plant-based protein, and healthy carbohydrates, we are naturally falling into line with low GI and low GL foods – producing a moderate glycemic response. The focus should be less on numbers, and more about feasting on nutrient dense foods which allow us to operate with an abundance of vitality, energy and vigour. In addition to organically sourced vegetables and low-sugar fruits such as berries or green apples, high-fat foods such as nuts and seeds and high-fibre grains such as brown rice, bulgur and quinoa are the most powerful regulators against diabetes, promoting overall good health and wellness. 

By following the 80/20 rule – 80% raw plant based foods, and 20% cooked – we are able to enhance the bioavailability of the nutrients that we consume, which is the optimum precedence for creating a balanced diet. The added benefit of eating this way is a sharp reduction in inflammatory triggers, such as gluten and dairy. 

Low Glycemic Foods List
0-55

Most non starchy vegetable 15
Peanuts 15
Low-fat yogurt, no sugar 15
Tomatoes 15
Cherries 22
Peas 22
Plum 24
Grapefruit 25
Pearled barley 25
Peach 28
Can peaches, natural juice 30
Soy milk 30
Baby lima beans 32
Fat-fee milk 32
Low-fat yogurt, with sugar 33
Apple 36
Pear 36
Whole wheat spaghetti 37
Tomato soup 38
Carrots, cooked 39
Apple juice 41
All-Bran 42
Canned chickpeas 42
Custard 43
Grapes 43
Orange 43
Canned lentil soup 44
Macaroni 45
Pineapple juice 46
Banana bread 47
Long-grain rice 47
Bulgur 48
Canned baked beans 48
Grapefruit juice 48
Green peas 48
Oat bran bread 48
Old-fashioned porridge 49

Medium Glycemic Foods List
56-70

Canned kidney beans 52
Kiwifruit 52
Orange juice 52
Banana 53
Potato chips 54
Special K 54
Sweet potato 54
Brown Rice 54
Linguine 55
Oatmeal cookies 55
Popcorn 55
Sweet corn 55
Muesli 5
White rice 56
Pita bread 57
Blueberry muffin 59
Bran muffin 60
Hamburger bun 61
Ice cream 61
Canned apricots, light syrup 64
Macaroni and cheese 64
Raisins 64
Couscous 65
Quick-cooking porridge 65
Rye crisp-bread 65
Table sugar (sucrose) 65
Instant porridge 66
Pineapple 66
Taco shells 68
Whole wheat bread 68

High Glycemic Foods List
70-100

Bagel 72
Corn chips 72
Watermelon 72
Honey 73
Mashed potatoes 73
Cheerios 74
Puffed wheat 74
Doughnuts 75
French fries 76
Vanilla wafers 77
White bread 79
Jelly beans 80
Pretzels 81
Rice cakes 82
Mashed potatoes, instant 83
Cornflakes 84
Baked potato 85
Rice, instant 91
French bread 95
Parsnips 97
Dates 100

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