Low-fat diets could raise the risk of early death by almost one quarter, a major study has found.

The Lancet study of 135,000 adults found those who cut back on fats had far shorter lives than those enjoying plenty of butter, cheese and meats.

Researchers said the study was at odds with repeated health advice to cut down on fats.

Those doing so tended to eat far too much stodgy food like bread, pasta and rice, the experts said, while missing out on vital nutrients.

Participants eating the highest levels of carbohydrates – particularly refined sugars found in fizzy drinks and processed meals – faced a 28 per cent higher risk of early death.

The NHS cautions against having too much saturated fat, on the grounds it raises cholesterol levels, increasing the risk of heart disease.

But the latest research, presented at the European Society of Cardiology Congress, in Barcelona found those with low intake of saturated fat raised chances of early death by 13 per cent compared to those eating plenty.

And consuming high levels of all fats cut mortality by up to 23 per cent.

The Canadian study tracked eating patterns and death rates across 18 countries.