The 'It' word these days is Protein. I see it dotted about all over packaging in the supermarkets right now - even in the confectionery aisle.
So does this mean that chocolate bars give you muscles and keep you fuller for longer? Unfortunately not. This is often products packaged in shiny new ways, where food manufacturers use (or abuse?) nutritional information to make their products more appealing, or adapt their recipes to adhere to UK labelling laws. Sorry to be the bearer of bad news!
In the UK, manufacturers have to follow certain rules in order to make health claims, such as 'source of protein' or 'high in protein'. For the former, this claim can only be made where at least 12% of the energy value (i.e. kilojoules/kilocalories) of the food is provided by protein. For a product to be high in protein, at least 20% of the kilojoules/kilocalories have to be provided by protein.