The locust position — why protein can make us thinner (Australian article)

[FeistyBrumby]

This was in an Australian paper.
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The locust position — why protein can make us thinner
By Graeme O'neill
November 6, 2005
Page 1 of 2



AN EMINENT Australian scientist has looked at locust behaviour to explain the growing obesity epidemic, leading him to support a high-protein diet as its solution.

Professor Stephen Simpson believes a primal appetite for protein drives the feeding behaviour of all animals, from locusts, beetles and spiders to vertebrates, including humans.

According to their "protein leverage hypothesis", University of Sydney entomologist Professor Simpson and colleague Dr David Raubenheimer at the University of Auckland suggest CSIRO's controversial "Total Wellbeing Diet" — criticised by some nutritionists for its high meat content — is "just about right".

"The fact that people lose weight on the diet and find it relatively easy to comply with is due to the power of protein to drive food intake," Professor Simpson said. "People stop eating when they satisfy their protein requirements."

The CSIRO diet recommends a doubling of average Australian dietary protein — to about 30 per cent of total food-energy intake — combined with slow-burning carbohydrates and reduced fats.

The former professor of entomology at Oxford University, who returned to Australia last year under the Federal Government's "brain gain" scheme, has strong experimental and epidemiological evidence for his hypothesis, from his research at Oxford on voracious African locusts.

"Nutrition science has been virtually devoid of theory," he said. "Despite all the experimental work, and many hypotheses, a conceptual framework has been singularly lacking."

Professor Simpson's hypothesis explains why radical and yo-yo dieting doesn't work. It also explains why members of former hunter-gatherer cultures such as Australia's Aborigines are susceptible to obesity and type II diabetes after switching to a low-protein Western diet.

His insight came from an experiment in which he starved locusts of protein, instead giving them a high-fat, high-carbohydrate diet. The insects gorged themselves in a vain attempt to satiate their hunger for protein. In another experiment, protein-starved locusts "zeroed in like missiles" on high-protein foods. Simpson said feeding experiments his team conducted on beetles and spiders at Oxford University (published in the journal Science earlier this year) support his idea that the requirement for protein drives and dominates the feeding behaviour of all animals, from lowly nematode worms to insects and vertebrates.


He said humans, like locusts and spiders, will consume whatever quantities of fats and carbohydrates are necessary to obtain sufficient protein to satisfy their primal appetite. The resulting excessive intake of fats and carbohydrates in Western societies has led to the obesity epidemic.

His solution is simple: a healthy weight can be maintained by lifting the proportion of protein in our diet from an average of 15 per cent to between 20-30 per cent. "This will take account of the fact that our modern lifestyles require less energy expenditure than those of our ancestors. By eating a higher protein diet we will obtain the amount of protein that our bodies want without having to eat more fat and carbohydrate than we need to sustain our lower energy needs," he said.

His hypothesis also explains the success of the popular but controversial Atkins diet, which prescribes a high-protein, high-fat formula for weight loss — at the risk of an increased likelihood of cardiovascular disease.

Professor Simpson said the Atkins diet comprised about 40 per cent protein — well over the minimum required to satiate protein hunger.

His hypothesis also provides an explanation for why weight gain and obesity are driven in a vicious cycle. "Putting on body fat … causes raised levels of free fatty acids in the blood, which, in turn, cause the liver to start burning protein," he said.

"This increases the appetite for protein and so causes further over-consumption of fat and carbohydrate. Breaking the vicious cycle requires shifting to a high-protein diet."

[Laurenfra]

Thanks for sharing