Page 18 - BBC - The Scientific Guide to a Healthier You

HOW FAT ARE WE?

More than half a billion people in the world are obese. with income – the prevalence of obesity is four times
Increasingly sedentary lives and a shift in diet are to higher in high-income countries than low-income ones.
blame. The South Pacific island of Samoa has the African and Asian countries generally have very low To be defined as
highest proportion of obese people – a whopping 74.6 obesity levels. Less than two per cent of the populations obese, you need to have
per cent are considered obese. In fact, South Pacific in Vietnam, Bangladesh, Nepal, India, Ethiopia, Eritrea, a body mass index (BMI)
2
of over 30kg/m . BMI is
nations reign in the top 10 – only Kuwait is not in the Madagascar and the Democratic Republic of the Congo calculated by dividing your
region. Elsewhere around the world, there is a direct link are considered obese. weight by the square
of your height.

FACT
Two times more
FACT
women (9.9%) are
5% of children
extremely obese
globally are
than men
considered
(5.5%) in the US
to be obese
KEY
Percentage
FACT
of population
Obesity is

> 30% FACT prevalent in the
2.8 million Middle East due
20-29.9% to an increasingly
people worldwide
10-19.9% die each year as sedentary lifestyle
a result of being and junk food
< 10%
overweight or
NO DATA obese

ARE ANTIBIOTICS MAKING US FAT?

The past few years have seen growing interest in levels of Christensenellaceae bacteria – one in 10 of
the idea that our gut bacteria play a crucial role in us – appear less likely to put on weight than those
regulating weight, and killing them off with with lower amounts. Scientists from King’s College
antibiotics is causing obesity. London have found that levels of this bacteria are
The most recent evidence is fascinating but partly genetically determined.
inconclusive. Studies in prestigious medical journals According to Dr Giles Yeo, who investigated the
have produced contrasting results. One found that possibility of microbial transplants to cure obesity,
three courses of antibiotics before the age of two this new field is important and requires research.
was associated with increased risk of early “But I have yet to see convincing evidence that there
childhood obesity, while the other found that are lean bacteria and obese bacteria,” he says.
exposure to antibiotics in the first six months of life

was not associated with early childhood weight gain. Verdict: More research needs to be done, but
Yet recent research is indicating a link between gut our gut bacteria may affect how readily we
fauna and our body mass index. People with higher put on weight.

18 BBC SCIENCE FOCUS MAGAZINE COLLECTION