The World Cancer Research Fund (WCRF) has suggested people may struggle to maintain a healthy weight without clear food labelling.
Maya Monteiro, senior education manager at the charity, explained to the Press Association that it is not always obvious when a food has a high calorific content unless it is clearly shown on product labels.
She called on the food and drinks sector to adopt a common system that is easy for everyone to understand, as this will help consumers to stay healthy in terms of the number of calories they are taking in.
Her comments followed the publication of a study showing that two out of three adults underestimate the content of foods such as houmous.
"This troubling lack of understanding is perhaps not helped by labels such as 'light' and 'reduced fat' when these are applied to foods which still have a high calorie content," added Ms Monteiro.
Mail Online described how houmous contains an average of 332 calories per 100g, with the WCRF describing any food with more than 225 calories per 100g as being high in energy density.
Another item that is often misunderstood by consumers is light mayonnaise, which has average of 259 calories per 100g, yet just 29 per cent of respondees to the YouGov poll were aware that it was in this high energy density content category.