What is the Atkins Diet?
The Atkins diet has long been regarded as a nutritional
heresy. Its cheery message that you can eat as many
calories as you like and still stay thin, simply by
cutting out the carbs, has always looked like better
marketing than science. The basic equation seemed to
break the first law of thermodynamics — the fundamental
principle that energy cannot be lost or destroyed. Robert
Atkins’s riposte — that protein and fat
make the body work harder to extract calories —
was unconvincing. It was hard to see how it could work.
Yet work it seems to do. Anecdotal evidence can be misleading,
but the experiences of the millions of Atkins devotees
make an intriguing case. They swear that the diet has
helped them to lose weight, when countless other regimes
have stubbornly refused to shift the pounds.
This week, that case won support from science. Two large
trials, conducted at Duke University in North Carolina
and the Veterans Affairs Medical Centre in Philadelphia,
found that obese people on Atkins lost as much, or even
slightly more weight, than those on conventional low-fat
diets. The low-carb regime also improved levels of “good”
HDL cholesterol and triglyceride fats linked to heart
disease.
The results chime with those of two other studies released
last year. The latest science suggests that Atkins can
be effective and that it may have health benefits. “We
can no longer dismiss very low carbohydrate diets,”
said Walter Willett, of the Harvard School of Public
Health, a long-time critic.
But we should still be wary. Science has given Atkins
only a tentative thumbs-up. The Philadelphia study covered
a year, while the Duke trial was even shorter, at six
months. While neither showed any adverse effects on
health, most experts believe these would take years
to show up. And even the scientists behind the new papers
think the potential dangers significant.
Will Yancy, who led the Duke team, said the low-carb
approach could trigger bone loss, kidney stones and
raised levels of “bad” LDL cholesterol.
And Yancy was funded by the Robert C. Atkins Foundation.
So little is known about the long-term hazards that
Yancy will not recommend the regime for first-time dieters.
Only obese people who have failed with other approaches
should give it a go. “Over six months the diet
appears safe but we need to study the safety for longer,”
he said.
Neither do the studies vindicate Atkins’s half-baked
theories about how and why his diet succeeds where others
fail. Research by Joe Donnelly, of Kansas University,
has indicated that these are probably wrong. Extracting
energy from fat or protein, instead of carbohydrate,
expends only a few extra calories, Donnelly has shown.
The best evidence suggests that Atkins works in the
same way as other regimes. People on the diet simply
eat less. The key to its success seems to lie in the
relative palatability of the foods on offer and perhaps
in the calming effect that its high protein content
may have on the appetite.
For all these caveats, though, Atkins deserves its week
in the sun. That is because it has done something all
too rare in the multi-million pound diet industry: after
years of selling itself on the back of anecdotal assertions
and testimonies, it has actually put its money where
its mouth is. Far too few of the publishers, companies
and health gurus who plug faddy diets based on anything
from cabbage soup to blood groups have channelled portions
of their vast profits into rigorous, independent, peer-reviewed
research to assess whether they actually work. Better
late than never, Atkins must be commended for seeking
proper scientific evidence for its claims.
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