The glycemic index was devised as a method of helping diabetics determine the effect of carbohydrate foods on their blood glucose levels. Foods are given a rating between one and 100 and this number determines how quickly that food will be broken down to release glucose into the blood stream. High GI foods can cause blood glucose and insulin levels to spike and therefore should be avoided if you suffer from diabetes. Low-GI foods are also thought to be more beneficial for those who wish to lose weight.
Basics
In order to follow a low-GI diet, you need to choose foods that are low on the glycemic index. A GI ranking of 55 or less is considered a low GI food, 55 to 69 denotes a medium-GI food and any food with a ranking of 70 or above is a high-GI food. On a low glycemic diet you should avoid foods with a high GI ranking or eat them in moderation together with a low GI food. High GI foods can be exchanged for a similar food that ranks lower. Produce such as meat, seafood, eggs and dairy foods are not listed on the glycemic index, as these foods have a very low or zero carbohydrate content and they do not cause spikes in blood sugar.
Vegetables
Vegetables rank low on the glycemic index and most types are suitable for a low GI diet. Optimal choices include broccoli, cabbage, onions, cauliflower and leafy salad greens, such as lettuce, kale and raw spinach. Medium-GI vegetable choices are beets and boiled sweet corn. Potatoes rank high on the glycemic index and therefore should be avoided or eaten only occasionally, preferably together with low-GI foods.
Fruits
Most fruits are suitable for a low-GI diet. Apples, peaches, cherries, plums and grapefruits are among the many common fruits that have a low-GI ranking. Pineapple, figs, mango and papaya have a medium reading. Watermelon and dates are very high and best avoided on a low-GI diet.
Breads
Generally the GI ranking of a food is in proportion with how much the food has been processed. For example raw vegetables have a lower-glycemic index than cooked vegetables. This also applies to bread; breads made with refined white flour rank very highly on the glycemic index. A white french-style baguette has an extremely high rating of 95, whereas wholegrain pumpernickel bread has a low index of 46. Opt for breads made with unrefined flour, such as wholewheat or rye breads when following a low-GI diet.
Cereals
Corn flakes and cereals aimed at children such as Coco-pops rank high on the GI. Rolled oats, porridge or natural muesli are low-glycemic index cereals that will cause little fluctuation in blood sugar levels.
Staples
Kidney beans, chickpeas, pasta and brown rice are among the staple foods suitable for a low-GI diet. Avoid all types of mashed potatoes, white rice, rice cakes and french fries.
Considerations
When selecting what to eat, the glycemic index should not be the only factor you consider. Total carbohydrate content, the type of fat a food contains, sodium and fiber content should also be considered. When making any dietary changes it is advisable to first consult with your health care provider or a nutritionist.
