Like many people, animals are getting fatter. At least, that is the finding of a report published in the British press.
Weight gain is often blamed on too much fatty food and too little exercise. But Professor Allison and his research team say there may be reasons other than these traditional ones.
The researchers studied body weight changes in more than 20,000 animals. The animals came from 24 populations of eight different species, or groups, across North America.
“Each animal was said to be in early middle age for its species. Yann Klimentidis worked on the study with David Allison. Mr. Klimentidis said they considered animals with at least two body weight measurements in the past 60 years. At least one measurement was made in the last half of the twentieth century. One exception was non-laboratory rats. Their body weight was first measured in 1948.
The study involved creatures as different as large animals in research centers and rats living free around Baltimore, Maryland. All the animals demonstrated major gains in average body weight over ten-year periods.
For example, chimpanzees in captivity showed a 33% increase in weight each decade. Laboratory marmosets increased weight at a rate of 9% over a ten-year period.
Laboratory mice became fatter at a rate of 10%. And laboratory rats increased at a 3% rate.
The study also showed that pet animals are fatter. The average house cat weighed almost 10% more each decade. Dogs’ weight increased at a rate of 3%.”
A virus called AD36 could be involved in the gain. Its presence has been connected to obesity in adults. And the team says changes in time spent in light or dark environments influence eating habits.
David Allison says earlier studies found that light differences may be part of the reason for fatter animals. For example, one kind of animal – the lemming – experiences body weight changes at different times of the year.
“We know that light affects weight gain in species like lemmings that gain or lose a great deal of weight in different times of the year, when there is much sunlight versus little sunlight. That is the natural thing for them. So our brains are responsive to light and in ways that may relate to body weight.”
David Allison says changes in environmental temperature affect weight in both people and animals. The body produces more energy to keep itself warm in the cold. But it produces less energy to cool itself in heat.
“That all other things being equal, if you put a warm-blooded species like humans or mice or dogs into a colder environment, then they will need to expend more energy to maintain their body temperature. And so, being in a cold environment increases energy expenditure, and if you eat the exact same amount, will lead to lesser body weight. Being in a warmer environment, up to a point, will lead to decreased energy expenditure, and therefore, at the same amount of food intake, weight gain.”
Yann Klimentidis says knowing causes of weight gain in animals may help researchers as they deal with overweight human beings.
VOCABULARY:
at least – pelo menos finding – descoberta
British press – imprensa britânica weight – peso
blamed on – atribuído a research team – equipe de pesquisa
measurements – medidas century – século
creatures – criaturas average - média
captivity – cativeiro increase – aumento, aumentar
marmosets – saguis (macacos pequenos) mice - ratos
environments – ambientes lemming – lemingue
a great deal of – muito brains – cérebros
both …. and… - tanto …. quanto to cool – esfriar
expenditure – gasto lesser – menor
therefore – portanto intake – ingestão
to deal with – lidar com
1. In the beginning, the text says that “like many people, animals are getting fatter”. This means that the article is about:
a) people losing weight d) people dying
b) animals getting heavier e) animals losing weight
c) animals getting sick
2. Which of the following is not a possible cause of weight gain in animals?
a) the virus called AD36
b) amount of time spent in light and dark environments
c) environmental temperature
d) fast food (hamburger, French fries, etc)
e) none of the answers above
3. According to the article, why is understanding weight gain in animals important?
a) It will make the animals happier.
b) It will give us information about diseases.
c) It´s interesting, but not important.
d) It may help researchers deal with overweight people.
e) It will make us fatter.
4. “Fatter” is in the comparative of superiority. Which of these words is not in the comparative?
a) slower d) heavier
b) sinner e) thicker
c) thinner
5. “Mice” is the plural of mouse. It is an example of irregular plural. Which noun also forms its plural in an irregular way?
a) goose d) marmoset
b) lemming e) monkey
c) brain
6. Which of these words from the text is NOT in the plural?
a) changes d) studies
b) says e) reasons
c) creatures
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