Blend banana, oats, plain yogurt and milk or an unsweetened alternative until smooth. A spoonful of nut butter can add flavour and richness if it suits your diet.

Oats are a whole grain, and WHO recommends that carbohydrate sources come primarily from whole grains, vegetables, fruits and pulses. Combining several whole-food ingredients can make a smoothie more substantial than fruit juice alone.

If the banana is very ripe, taste before adding any sweetener — you may not need it. Adjust thickness with liquid rather than juice.

For people with allergies or specific dietary needs, choose appropriate substitutes and check labels.