Dr Alan Barclay
Starchy vegetables – 10 things you need to know for better blood glucose
1. When it comes to seriously starchy vegetables like potatoes, sweet potatoes, corn, taro and yams, you need to think of them as the Vegetable Kingdom’s equivalent to rice or pasta. Their GI is very relevant when it comes to managing your blood glucose levels and you need to be moderate with what you put on your plate.
2. Root vegetables like beetroot (GI 64), carrots (GI 41), parsnips (GI 52), swedes/rutabaga (GI 72) and vegetable fruits and seeds like squash/pumpkin (GI 66), green peas (GI 48) and legumes or pulses (GI 14–53) have smaller amounts of carbohydrate than potatoes and are packed with micro-nutrients. A typical serving size won’t give your blood glucose levels an excessive boost, even the ones with higher GI values.
3. But, there’s no need to say ‘no’ to potatoes just because most varieties have a high GI. They are fat free (when you don’t fry them), nutrient rich and filling. Not every food you eat has to have a low GI. So enjoy them in moderation. But look for the lower GI varieties or serve them in a way to reduce their glycemic impact – such as potato salad with a vinegary vinaigrette dressing.
4. Starchy vegetables are a good source of fibre (when you don’t peel them) and micro-nutrients including vitamin A (yellow/orange-fleshed veggies), B vitamins, vitamin C and potassium.
5. Some, like legumes or pulses, are important sources of protein, especially for vegetarians or vegans.
6. They tend to be ‘feel-full’ foods. Their high fibre and water content means that they are bulky, and help to satisfy your appetite.
7. They aren’t fattening by themselves. It’s how you cook them and what you pour over them that adds the calories (kilojoules).
8. They are great mixers. Combining them in bakes or gratins or pilafs will boost the variety of vitamins, minerals and phyto-nutrients you get and lower the GI if you combine higher GI veggies with low GI ones, eg mashed potato with butter beans.
9. Their place is the carb quarter of the dinner plate (and within the inner rim too and not piled up like a pyramid).
10. Here’s what a serving of the most popular starchy vegetables is equal to: 1 medium (13 cm/80g) ear of corn, ½ cup (90g) corn kernels, ½ cup (85g) cooked chickpeas, kidney beans, borlotti beans etc., 2/3 cup (125g) cooked lentils, 1 cup (180g) cooked split peas, ½ cup diced sweet potato (90g), 2 small new potatoes or 1 medium sized (125g) and ½ cup mashed potato (120g).
For more information about the GI Symbol Program
Dr Alan W Barclay, PhD
Chief Scientific Officer
Glycemic Index Foundation (Ltd)
Phone: +61 (0)2 9785 1037
Mob: +61 (0)416 111 046
Fax: +61 (0)2 9785 1037