Carbs

For each one: how to use it, the best version, how to prepare it, what it does, and where it goes wrong.

Purple sweet potato

The same tuber with a different pigment. Purple is anthocyanin, the same compound as in a blueberry, and there is a lot of it.

How to use it: As the starch on your plate, or roasted as a side where the colour does the work. It is firmer and less sweet than the orange one.
Glycemic index: No separate reliable value for the purple variety appears in the international tables. Reckon on the neighbourhood of the orange one, and lower if you let it cool first.

Read on

Starch with colour in it. That colour is provitamin A, and in children who were short of it that has simply been measured.

How to use it: As the main source of starch on your plate, in place of white potato or rice. With fat alongside, because the pigment only dissolves in fat.
Glycemic index: 63. Boiled. Roasting it until it caramelises pushes it higher, and it varies a lot by variety.

Read on

The same tuber without the colour. What you get is the starch and the fibre, and not the provitamin A.

How to use it: As the starch on your plate. It is drier and less sweet than the orange one, so it suits savoury food and a stew better than the oven with cinnamon.
Glycemic index: No separate reliable value for the white variety appears in the international tables. Reckon on the neighbourhood of the orange one, so mid-range, and lower if you let it cool first.

Read on