Homemade protein bars are cheaper than shop-bought ones and you know exactly what is in them. The only trick is the texture: add the milk a spoonful at a time until the mixture just holds together when pressed. Too wet and they never set firm.

Each bar has about 12g of protein and just over 210 calories. Over a fifth of its energy comes from protein, which meets the UK threshold for calling a food "high protein". The protein comes from the whey, peanut butter, oats and milk.
Why homemade is worth it. Many shop-bought protein bars rely on sweeteners, sugar alcohols and long ingredient lists to get their numbers. This has six main ingredients, plus a pinch of salt. Choose a peanut butter made only from peanuts.
The honest part is the calories. Peanut butter is calorie-dense, so at about 210 calories these are a proper snack rather than a light one. One is a sensible portion after training or as an afternoon snack; two would be more than many people need. Most of the fat is unsaturated.
Added sugar. The honey and chocolate add about 4g of sugar a bar, much less than most flapjacks or cereal bars. The NHS advises adults to have no more than 30g of free sugars a day.
Allergy notes. Contains peanuts and milk. Use oats labelled gluten-free if you need to. For a vegan version, use a vegan protein powder, maple syrup and plant milk; the protein will be slightly lower. Dark chocolate with 70% cocoa or more has less sugar than milk chocolate. For a smaller bite-sized snack, try the date and cacao protein balls.