It's the abundance of food that's been causing an obesity epidemic, claims a new research.

Of the 56 out of 69 countries surveyed, average body weight had increased as a result of available food supply, with only countries hit by famine, natural disasters or civil war not in the list.

Researchers from the University of Auckland, New Zealand, and the National Institutes of Health in the US, said that it was major factor in the growing obesity epidemic throughout the world, the Telegraph reported.

In Britian, researchers found that each person had 3428 calories available to them each day, which was 70 per cent more than required by women, and 37 per cent more than men's recommended daily intake.

It has risen by 212 calories since 1993.

Lead author Stefanie Vandevijvere said their study showed that oversupply of available calories possibly leads to overconsumption of those calories, resulting in the weight gain seen in most countries.

Scientists also found that the increases were far in excess of what was required to explain the weight gain experienced by each country, suggesting that food waste had also increased substantially.

Weight gain has been stated as a risk factor for many major health problems, like diabetes, heart disease, stroke and even some cancers.

The study highlights the need for the governments to implement policies to make food healthier.

Dr Francesco Branca, director of the Department of Nutrition for Health and Development at WHO, countries need to look at how they guide the food system, and work across sectors including agriculture, the food production, distribution and retail industries, health, social welfare and education.

The study is published in the Bulletin of the World Health Organisation.