Ultra-processed foods are replacing healthy diets “around the world” despite growing evidence of their dangers and should be sold with warnings like those on tobacco products, according to the nutritionist who first coined the term.

The professor Carlos Monteiro of the University of São Paulo will highlight the growing risk of such products to children and adults at the International Conference on Obesity this week.

“Ultra-processed foods are increasing their market share and dominating global diets, despite the health risks they pose,” Monteiro told the Guardian ahead of the conference in Sao Paulo.

“Ultra-processed foods are displacing healthier, less-processed foods around the world, and are also causing a deterioration in the quality of nutrition due to their many harmful properties. These foods are driving the obesity epidemic and other diet-related chronic diseases such as diabetes.”

The stark warning comes amid rapidly growing global consumption of such products as cereals, protein bars, fizzy drinks, ready meals and fast food.

In the UK and US, more than half of the average diet now consists of highly processed foods. For some, especially younger or poorer people, their diet includes up to 80% highly processed foods.

In February, the world’s largest study of its kind found that highly processed foods are directly linked to 32 harmful health effects, including a higher risk of heart disease, cancer, type 2 diabetes, poor mental health and early death.

Monteiro and his colleagues first used the phrase “ultra-processed food” (UPF) 15 years ago when they were designing the “Nova” food classification system. This assesses not only the nutritional content but also the processing the food undergoes before consumption.

The system places foods and beverages into four groups: minimally processed foods, processed cooking ingredients, processed foods, and highly processed foods.

Monteiro told the Guardian that he is now so concerned about the impact of these foods on human health that the studies are not sufficient to warn the public of the dangers.

“Public health campaigns like those against tobacco are needed to reduce the risks,” he told the Guardian.

“Advertising for highly processed foods should also be banned or greatly restricted and front-of-pack warnings similar to those used on cigarette packs should be introduced.”

It also calls for a ban on the sale of such products in schools and health facilities and for them to be heavily taxed, with the revenue generated being used to subsidize fresh food.