Any immediate benefits, such as greater alertness, are outweighed by longer-term health problems—but it's something the energy drink industry isn't telling the public, say researchers from the Harvard T H Chan School of Public Health.

The drinks generate around $10bn sales in the US alone every year, partly because they are marketed as a healthy option to improve energy levels, stamina, athletic performance and concentration.

But the drinks' high levels of caffeine and sugars can cause a wide range of life-threatening health problems, such as hypertension, kidney damage, obesity, and mental health problems such as stress and anxiety.

The impact could be even more severe in children and adolescents—who are often the focus of the energy drink industry's marketing—although its extent isn't known because it's never been assessed.

As a precautionary move, the sale of the drinks should be restricted, and children and adolescents should be barred from purchasing them, the researchers say.