Tam Fry, of the National Obesity Forum, said: “The calories in these healthy snacks are unbelievable. They can never be regarded as snacks because they break all the latest advice from the department of health about how many calories you can consume in a full meal. They are not snacks, they are full meals.
“The fat levels are also extraordinary. It is unbelievable that a company could manufacture a snack that exceeds the number of calories in a full meal and as such they should come with a traffic light warning on the front of pack.”
It comes as peanut butter is becoming so popular that it is set to overtake jam as Britain’s favourite breakfast spread after a backlash against sugary foods, Kantar Worldpanel figures show.
Sales of the nut-based spread were up by nearly a fifth in 2017 and are set to break through the £100 million barrier, thanks to the introduction of new “healthy” upmarket versions.
Brands at the top end of the market include Whole Earth, Meridian, Manilife and Pip & Nut while some supermarkets have introduced their own premium ranges of peanut butters.
An M&S spokesman said: “We offer customers a variety of different snacks and all are clearly labelled with nutritional information. All our heathier snacks are clearly labelled with our Eat Well Sunflower which is an easy signpost for customers looking for healthier options in our stores.”
Pret and Pure have been contacted for comment.