Table A1.

Consistent themes emerging from the data and keywords that summarise participant responses related to whole grain knowledge, attitudes, consumption and health literacy, in descending frequency.

Theme	Subthemes/Keywords	Exemplar Quotes
Whole grains	Unprocessed	“Unprocessed grains”
	Natural	“Natural”
	Whole grain	“Includes the whole grain”
	Unsure	“I don’t know”
	Containing husk	“Grain that contains all its components”
	Not crushed/ground	“Grains that are still whole, not crushed up”
	Seeds	“Grain food with seeds”
Diet importance	Fibre	“Good source of dietary fibre”
	Nutrients	“Provide nutrients”
	Less processed	“The food that have the least processing are better for you”
	Natural	“They’re the most natural, best for you”
	Unsure	“I heard they are good for you but unsure why”
	Healthier choice	“Seems like a healthy choice”
	Fuller for longer	“Appetite control”
	Digestion	“Good for the digestive system”
	Bowel health	“Keep you regular”
	Gut health	“It is important for gut health”
	Low GI	“Some have a low glycaemic index”
	Healthy diet	“Important part of a balanced diet”
Health benefits	Fibre	“Higher fibre”
	Gut health	“Improves gut health”
	Digestive health	“Good for digestion”
	Low GI	“Lower GI so good for combating diabetes”
	Regularity	“To assist in regular bowel movements”
	Nutrients	“More nutrition content than processed grains”
	Lowers cholesterol	“Lower cholesterol, better for heart”
	Fuller for longer	“Keep fuller longer and better for you”
	Heart health	“Reduce risk of heart disease”
	Blood sugar control	“Helps control blood sugar levels”
	Reduced diabetes risk	“Reduce risk for diabetes”
	Lower cancer risk	“Lower bowel cancer risk”
Barriers to purchasing	Taste	“Worried about lack of taste”
	Price	“If they are priced considerably more than traditionally processed foods”
	Family influences	“My family not liking the taste. If it wasn’t for them I’d buy them”
	Texture	“Texture in things like bread and wraps”
	Dietary requirements	“We are coeliac and eat gluten free”
	Culinary use	“Compatibility with food dishes that I am cooking”
	Diet choice	“Rarely eat foods containing gluten”
	Cooking	“Unsure how to cook some of the rarer ones”
Negative grain association	Gluten-free diet	“Many people seem to think a gluten free diet is healthier”
	Weight gain	“Weight issues and paranoia about gluten fattening, I’ve cut out carbs at dinner”
	Taste	“Husband says grains taste like bird seed”
	Carbohydrates are bad	“Too many carbs are meant to be bad for you”
	Paleo diet	“Friends following paleo diet”
	Keto diet	“Carb free diets and keto”
	Fad diets	“People who are dieting avoid them”