Compared to other varieties of bread, wholegrain bread has a lower glycaemic index (GI).

And that’s good news if you’re trying to lose weight, because a low-GI, carbohydrate-rich diet is one of the most effective for weight loss, particularly for women, according to University of Sydney research.

The GI is a measure of how carbohydrate-containing foods impact blood sugar, and unlike high-GI foods, which contribute to hunger and prevent the breakdown of fat, lower-GI foods increase the rate of body fat loss.

To get the biggest benefit:
Choose a loaf that contains barley, which has a specific mix of dietary fibres that’s effective at keeping a lid on appetite.

Compared to white and whole wheat breads, eating sourdough bread creates a smaller rise in post-meal blood-sugar and insulin levels, which helps to lower your risk of developing type 2 diabetes.

And it’s an effect that lasts – eat sourdough at one meal and the positive effect on blood glucose and insulin lasts until after your next meal, too. The fermentation process required to make traditional sourdough alters the make-up of the bread’s starch content to create a blood-sugar friendly loaf.

To get the biggest benefit:
Buy sourdough bread that’s made traditionally, using a ‘starter’ yeast. Commercial bakeries often replace this starter with dried powdered yeast, so do your research before choosing a loaf, or buy one from your local bakery where you can ask how the bread is made.

It boosts levels of Lactobacillus, a strain of gut bacteria that’s effective against antibiotic-resistant diarrhoea, which affects about 30 per cent of people taking antibiotics.

Researchers are yet to work out why, but say it’s probably thanks to a combination of white-bread ingredients, rather than one in particular.

To get the biggest benefit:
Choose a high-fibre white bread. These are ‘fortified’ with fibre to replace what’s stripped during the refinement process required to make white flour, and some commonly used fibre-enriching ingredients also promote the growth of beneficial gut bacteria.

Rye bread has a much bigger effect on satiety (or how full we feel), than loaves made purely from wheat flour. In fact, eat rye bread for breakfast and you’ll eat less at lunchtime.

Rye bread is a rich source of fibre, which may explain its hunger-fighting effect, because fibre helps to keep you fuller for longer.

To get the biggest benefit:
Choose the darkest rye bread you can find. Rye bread is made from a combination of rye flour and wheat flour, and the darker the colour, the more rye flour it contains.

Text: Karen Fittall/Good Health