46 | New Scientist | 7 May 2022
Features
F
or as long as Kimrey Rhinehardt can
remember, she has been trying to lose
weight. The keto and paleo diets seemed
to work... for a while. But when the weight
came off, her emotional eating and sugar
cravings ruined her efforts.
Rhinehardt’s battle to control her weight
has been frustrating, but for the management
consultant from Pittsboro, North Carolina,
it is also dangerous. She has high cholesterol,
asthma and a family history of breast cancer.
Her weight raises the likelihood she will die
from one of these risk factors.
Then, six months ago, a doctor prescribed
her weekly injections of a new kind of
medication, and everything changed. She lost
more than 27 kilograms and her body mass
index (BMI) dropped from 41 – considered
severely obese – to 32, just over the threshold
for obesity. The drug even changed her
perspective on food. Rhinehardt isn’t
interested in many of the unhealthy snacks
she used to love. “Cravings for sugar and
bread don’t exist any more,” she says.
This new drug, semaglutide, marketed as
Wegovy in the US, was approved last year by
the US Food and Drug Administration (FDA).
For Rhinehardt, it has been the boost she
needed to finally lose the weight she has
struggled with for decades. But for some in
the medical profession, the hope is that the
drug might revolutionise our fight against
one of the most prevalent and lethal health
problems in much of the world. Not only
could it help treat obesity in people finding it
hard to lose weight, but it might even be used
to prevent the condition in the first place.Obesity is a chronic health issue that puts
people at risk for other chronic conditions,
including cancer, diabetes, heart disease and
sleep apnoea. It is also the most common
health condition in both the UK and US:
28 and 42 per cent of their adult populations,
respectively, are obese. In 2016, when the latest
figures from the World Health Organization
(WHO) were made available, 13 per cent of
adults globally were obese, a figure that had
nearly tripled since 1975. Most of the world’s
population now live in countries where being
obese or overweight kills more people than
being underweight.
Obesity on this scale may be a modern
malady, but the promises of quick fixes for
losing weight have been with us for centuries.
In the 1800s, soap and arsenic were touted
as good options for those wanting to slim
down. By the 1930s, dinitrophenol – an organic
compound that can cause rapid breathing, a fast
heart rate and heavy sweating and can, in some
cases, prove fatal – was promoted for weight
control. And prior to a US ban in the 1970s,
amphetamines became a fashionable means
of appetite suppression, despite powerful side
effects, including the risk of heart problems.
Even drugs approved by the FDA have
flopped. Fen-phen, named after the two
appetite-suppressing drugs it contained,
fenfluramine and phentermine, was
considered the star of diet drugs in the
1990s until it was withdrawn from the market
because it caused heart valve defects in as
many as a quarter of people taking it. In 2020,
another diet drug, lorcaserin, was pulled from
sale when it was linked to a range of cancers,“ The drug
might even
be used to
prevent
obesity in
the first place”
Obesity blockers
A new class of drug promises to help people lose
huge amounts of weight and may even prevent
obesity. Will these medications live up to the hype,
asks Sara Novak