Trendy peanut butter snacks contain so many calories they should be classed as meals, obesity campaigners have said.

Food outlets including M&S, Pret and Pure are all selling peanut butter snacks which experts have described as having "unbelievably high" calorie contents.

Pure has a "Pip and pure" snack pot containing apple chunks and peanut butter, topped with toasted coconut chips which at 425 calories contains roughly the same number as one of its blueberry muffins (427 cal).

M&S's new vegan "plant kitchen" range features a crunchy apple wedges with peanut butter dip snack which has 330 calories. This is more than a roasted vegetable and avocado sandwich also within in the range, which has 311 calories.

Meanwhile Pret has an acai and almond butter bowl which contains granola and sliced banana and comes in at 371 calories.