biology evolved to expect a variety of foods
across the seasons, to fast overnight, and
to experience times of feasting and famine.
Physiologically, we are like athletes who
need to stretch their muscles and tendons
to maintain the ability to respond flexibly
to whatever challenge is thrown at them.
Unless we keep our physiology ‘stretched’,
we will gradually lose the ability to enjoy a
healthy variety of diets.
Now, there is no doubt that weight loss
can be a good thing for health and lifespan
– if you are above a healthy weight and
especially when there are signs of diabetes
and cardiovascular disease. Its benefits for
improving all manner of markers of poor
health associated with obesity are legion.
But knowing what we now know about
the molecular mechanisms of longevity, a
high-protein, low-carb, high-fat diet poses
a potential risk of its own. Our experiments
with insects and mice, supported by
research by other scientists around the
world, show that such diets activate ancient
and universal biochemical pathways that
stimulate growth and reproduction. But at
the same time, they switch off the repair and
maintenance pathways that help support a
long and healthy life.
Is there evidence that such risks are
real in humans? There is a growing body of
evidence, but studies have yet to run long
enough to say for sure. For obvious reasons,
we can’t run highly controlled lifelong
experiments on human nutrition the way we
can with insects and rodents. Interpreting
the results from short-term dietary trials
in humans and from nutritional surveys
is fraught with difficulties. Conclusions
are often disputed by the proponents of
different dietary camps, who usually have a
single-nutrient focus, commonly squabbling over the relative roles of
fats versus carbs.
Still, it’s undeniable that we humans share the same basic
molecular biology as yeast, worms, flies, mice, and monkeys when
it comes to the longevity and growth pathways. This leaves us with
a question: What are the odds that our species is a rare exception
to the rule that long-term exposure to a high-protein, low-carb diet
is life-shortening? Pretty low, we think. Vanishingly so. Especially
when you consider that the longest-lived, healthiest populations on
the planet are those who consume a lower-protein, high-carb wholefood
diet.
WIN!
1 OF 3
COPIES
David Raubenheimer
David is the Leonard P. Ullman Professor of Nutritional
Ecology in the School of Life and Environmental Sciences,
and Nutrition Theme Leader in the Charles Perkins Centre
at the University of Sydney. He previously spent ten
years as a Research Fellow and departmental Lecturer
at Oxford.
Stephen James Simpson AC FRS FAA
Stephen is the executive director of Obesity Australia and
the academic director of the Charles Perkins Centre. Born
in Australia, he graduated with a BSc from the University
of Queensland in 1978, and completed his PhD at King’s
College London in 1982 on locust feeding physiology.
YOUR CHANCE TO WIN!
Through studying appetite in animals, David Raubenheimer
and Stephen Simpson have been transforming the science
of nutrition. In their book Eat Like the Animals they take us
on a journey from jungle to laboratory and back to our own
kitchens.
For your chance to win 1 of 3 copies of Eat like the Animals
email [email protected] and let us know in 50
words or less why you want to know more about the animal
instincts of eating for optimum wellbeing.
56 | NETWORK WINTER 2020