EAT LIKE THE ANIMALS
THE PROBLEM WITH TOO
MUCH PROTEIN
In this abridged extract from their book Eat like the Animals, scientists David
Raubenheimer and Stephen Simpson look at how and why we eat, how appetites
are fed and regulated, and how, in the end, it all comes back to protein.
M atthew is twenty-five years old.
He moved away from home after
finishing university a year ago and
is working full-time in an office in
a new city. The hours are long, and he’s
expected to be there late most evenings.
Cooking has never been his thing, and online
deliveries are so easy. In his late teens,
Matthew was a talented footie player and
trained hard to build bulk. Over three years
he beefed up from a gangly beanpole to a
muscular 85 kilograms. He drove his parents
to distraction with his blended protein
shakes and eggs and multipacks of chicken
breasts that cluttered the family refrigerator,
but those days have gone. His football days
are also over, and with them his intense
training regime.
During his life as an athlete, Matthew was
eating around 135 grams of protein each day,
which he needed to build and maintain his
ample muscle mass. He was also expending
3,550 kcal of energy daily, needed to fuel his
high level of physical activity. Now, he sits in
front of a computer screen all day at work
and is burning only 2,550 kcal each day.
His muscle mass is starting to waste away
without football and weight training – if you
don’t use it, you lose it – but it’s still making
its demands felt through his protein appetite.
At the end of his athletic career, Matthew
could hit the bull’s-eye for both protein and
energy if he stuck to a 15% protein diet
(eating 135 grams of protein would mean
eating 3,600 kcal). The problem today is that
he now needs 1,000 fewer calories a day.
To eat that amount on a 15% protein diet
would provide Matthew with just 95 grams
of protein per day. His protein target, still for
now set high, courtesy of his sporting days,
will remain unsatisfied, urging him to keep
eating.
It will take time for Matthew’s protein
target to reset to a lower level more suited
to his new sedentary lifestyle. How long,
we don’t know. The science remains to be
done, but by then Matthew’s waistline will
be showing the effects of the accumulated
excess calories he will have eaten chasing
a high-protein target set during athletic
A common
rookie error
is to look at
the health
benefits of a
higher-protein
diet and credit
protein itself.
54 | NETWORK WINTER 2020