For years whole milk has been shunned by health-conscious adults in favour of semi-skimmed or plant milk – but old-school dairy products such as “full-fat” milk and Greek yoghurt are staging a comeback.

Retailers are reporting rising sales of whole milk, full-fat yoghurt and blocks of butter – with skimmed milk and low fat yoghurt left on the shelf – as customers go back to basics to avoid processed food.

Searches for the terms “full-fat milk” and “full-fat yoghurt” have soared on Waitrose’s website in the past month, up 417% and 233% respectively, while “block butter” is up 280%.

“We’re seeing a long-term trend of ‘low fat’ losing interest as a health focus,” said Kiti Soininen, category director for UK food and drink research at Mintel.

In 2018 32% of people put “low-fat” in the top three things they looked for in healthy food but by last year that had fallen, Soininen said. At the end of last year the top three factors were “low sugar content” (31%), “contributes to five-a-day” (24%) and “low fat” (24%).

The less hardline stance on fat being taken by consumers is down to a number of factors, not least the furore over ultra-processed food (UPF). At the same time more recent research studies suggest the link between saturated fat and heart disease is not as strong as once thought.

The nutritionist Alexa Mullane said: “It’s now understood that fats from whole foods, when consumed in moderation as part of a balanced diet, are not as harmful as previously believed, and actually have some health benefits.”

In Waitrose, full-fat dairy products are selling better than low-fat substitutes. The supermarket chain attributes this to concern about UPFs, with its customers turning away from low-fat, highly processed products in favour of less processed, whole-food ingredients.