Protein bar

Mix oats, nut butter and protein powder with a little honey or water until the mixture holds together. Press it firmly into a lined tin, chill for 1–2 hours, then slice into bars and keep them refrigerated.

Keep unopened bars in a cool, dry cupboard, away from direct sunlight; heat can soften chocolate coatings and make nut oils turn rancid faster. Once opened, wrap the bar tightly and eat it promptly.

Yes. Wrap each bar separately and freeze it in an airtight container; thaw it while still wrapped so condensation stays on the wrapper rather than making the bar sticky.

Pair one with a piece of fruit, such as an apple or banana, or with plain yoghurt for a more substantial snack. If the bar is coated in chocolate, coffee or tea makes a simple accompaniment.

Not necessarily: many contain peanuts, tree nuts, milk proteins or soy, and some are made on shared equipment. Read the ingredient and allergen information each time, especially if you are choosing a different bar.

A protein bar has 22 g of protein per 100 g, compared with 7.9 g in a muesli bar. Muesli bars are usually more carbohydrate-heavy: they provide 61.7 g per 100 g, against 30 g in a protein bar.

You can, but it need not replace ordinary snacks or meals: bars are convenient when you are travelling or short on time, while foods such as yoghurt, eggs, beans or nuts offer other choices. Check the ingredients if you want to avoid particular sweeteners or allergens.