Why carbohydrates

Carbohydrates - Understanding Whole Grains

Whole grains are a good source of energy, and may also be a useful and important source of fibre, calcium, iron, zinc, B vitamins and various other nutrients in our diets. However, it can be a bit confusing to work out what is a whole grain, and why they are different to other types of starchy carbohydrate foods. In the video, you saw me give an analogy between whole grains and avocado. I explain it in more detail here.

The skin is like the bran: This is a fibre-rich outer layer. This slows down the digestion and absorption of the starchy central part.

The flesh is like the starchy central part, called the endosperm. This is converted into sugars once digested and absorbed.

The stone is like the germ, the nutrient-packed inner part. This is where much of the nutritional density of whole grains come from.

I tend to divide grains up into three categories in my mind, to simplify things and hopefully make it easier to pick nutritious choices and understand why. There aren't any universally agreed definitions, but I have found this to be a useful 'rule-of-thumb'.

Wholegrain

Where the grain is in a similar state to how it was growing on the plant, and still contains all parts of the grain - the bran, endosperm and germ - relatively intact.

Wholemeal

Where the grain has been processed and milled. The bran, endosperm and germ (and therefore important micronutrients) are usually still there, but they have been broken down, leaving more of the endosperm (starch) available for quick digestion and absorption.

Refined / White

This is where the bran and germ have been removed and only the endosperm is left behind. Refining grains like this reduces their micronutrient density (i.e., the amount of vitamins and minerals they contain) and makes digestion and absorption of the carbohydrates easier, and thus quicker. Flours may, however, then be fortified with nutrients again after processing.

Examples of Whole Grains Might Include:

• Brown / wild rice
• Spelt or durum wheat
• Whole oats
• Corn (maize)
• Buckwheat
• Naked barley
• Rye
• Millet
• Quinoa
• Other 'ancient' grains - freekeh, amaranth, gamut.