A teaspoon of oil, measured out with precision, is how Professor Tim Benton remembers his mother preparing items for frying.

When he was growing up in the 1960s, vegetable oil was still a precious commodity and used sparingly.

Fast-forward to today and oil is now so abundant and cheaply available that most of us use it liberally in our cooking – chucking it in anything from salad dressings to deep fat frying.

It’s not only in our home cooking, oil is also an ingredient in most of the items we buy from the supermarket.

In fact, vegetable oil, specifically soy bean oil and palm oil, are two of the eight ingredients, alongside wheat, rice, maize, sugar, barley and potato, that are now estimated to provide a staggering 85% of the world’s calories.

Increasingly, no matter what country we live in, we all eat similar diets which are heavy in calories and low in nutrients.

It’s a development that Prof Benton, a strategic research dean at the University of Leeds specialising in food security and sustainability, links directly to global trade.

The production of vegetable oils and oil crops have both increased considerably over the past three decades.

The rise has been driven by a combination of trade agreements, which have made it cheaper and easier to export and import oil, and various government policies. Subsidies in countries such as Malaysia and Indonesia, aimed at ramping up production for export, have helped to lower the cost of vegetable oil, for example.

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