Why we can blame our ancestors for the way we crave fatty junk food

Why we can blame our ancestors for the way we crave fatty junk food

By Fiona Macrae
Last updated at 3:00 AM on 13th February 2009


Deep rooted: A genetic craving for junk food can be traced back two million years(posed by model)

Unable to resist ordering chips or eating just one more biscuit? Blame your ancestors.

Scientists believe that our cravings for fatty, salty and sugary foods have their roots deep in evolution.

They say our modern-day taste for junk food can be traced back two million years, to a time when the brains of early humans rapidly increased in size.

To satisfy the energy demands of their burgeoning brains the first members of the Homo genus - direct ancestors of modern man - developed a taste for high calorie foods.

But they kept in trim because they had to widen the search for their dinner.

Researcher William Leonard said: 'While our large-bodied ape relatives, chimps, gorillas and orang-utans, can subsist on leaves and fruit, we needed to consume meat and other energy-rich foods to support our metabolic demands.

'To obtain these higher-quality diets, our foraging ancestors would have had to have moved over larger areas than our ape relatives, requiring large activity budgets.

Twenty first century man, has retained a sweet tooth and a big brain.

But he is loathe to exercise, putting him at risk of obesity, as well as high blood pressure, heart disease and diabetes, the American Association for Advancement of Science's annual conference heard.

Professor Leonard, an anthropologist from Northwestern University in the US, said: 'Think about our ancestors.

'Human hunter-gatherers typically move eight miles per day in search for food.

'In contrast, we can simply pick up a phone to get a meal delivered to our door.

'These reductions in daily energy expenditure associated with our modern lifestyles are a major contributor to the growing problem of obesity throughout the world.

'We are in many aspects victims of our evolutionary success.'

Stressing that exercise is key to winning the battle of the bulge, he said: 'Two of the factors most often cited for the dramatic increases in obesity rates are the ever-greater availability of inexpensive high calorie/high fat food items and the expansion of portion sized ie the "Supersize Me" phenomenon.

'Yet, while these changes in consumption patterns are clearly contributing to the problem, they are not the entire story.

'The obesity epidemic cannot be understood solely by looking at "intakes"; rather we must also consider energy expenditure and activity patterns.'

Peter Ungar, an anthropologist from the University of Arkansas, said history suggests we should eat everything in moderation.

The professor said: 'At the onset of agriculture, when people started to domesticate animals and grow crops our health status declined dramatically.

'Average human stature dropped, there's evidence of all kinds of malnutrition and related diseases, tooth cavities started to appear.

'That's because not so much that we changed our diet from one thing to another but that we greatly decreased the range of foods that we consumed.

'What we shouldn't be doing is focussing on just a few foods. The typical American diet is mostly processed flour, fat and occasionally people throw some tomato sauce on top.

'The real secret here is a broad-based diet that incorporates a great number of different types of food items to ensure that we get all the nutrients that we need and none in excess.'

Source: http://www.dailymail.co.uk/sciencetech/article-1143873/Why-blame-ancestors-way-crave-fatty-junk-food.html