The far-right leader offered this idea in response to a journalist's question as to whether it was possible to simultaneously spur economic growth, feed the world's hungry and also preserve the environment.

"It's enough to eat a little less. You talk about environmental pollution. It's enough to poop every other day. That will be better for the whole world," said Bolsonaro, who earlier this month sacked the head of a government agency that had reported a major increase in Amazon deforestation.

Bolsonaro has been criticized for a rapid acceleration in deforestation of the Amazon rainforest, which covers vast swathes of Brazil and is considered vital to combatting global warming.

According to Brazil's National Institute for Space Research (INPE), which tracks clear-cutting of the rainforest, around 2,254 square kilometers (870 square miles) of the Amazon were cleared in July, an increase of 278 percent from a year ago.

That followed a 90 percent increase in June compared to the year prior -- figures that Bolsonaro has called "lies," and which prompted the sacking of INPE chief Ricardo Galvao on August 2.

The rapid rise in deforestation has triggered a global outcry and threatens to create problems for the recent free trade agreement between the South American trade bloc known as Mercosur. The pact includes Brazil and the European Union.

The Amazon is vital to the exchange of oxygen for carbon dioxide in the atmosphere -- a check on global warming.

But Environment Minister Ricardo Salles said the INPE data was published in a way that satisfied "sensationalist interpretations" and was aimed at getting "more donations from foreign NGOs".

Data from INPE, an institution of international repute, showed that overall deforestation has increased 40 percent in the last twelve months compared with the same period a year ago.

Bolsonaro, a combative politician frequently denounced for derogatory remarks about women and minority groups, said the rapid rise in populations around the world needed to be addressed.

"When you see how the world's population is increasing by 70 million a year, you need a family planning policy," said the former army officer, declining to use the term "birth control" for fear of an adverse media reaction.

"Don't make me say that, otherwise (the daily) Folha de S. Paolo will run a headline saying I favor birth control," he said.

"But you can see that more educated people have fewer children. I'm an exception to that rule, I have five," he said.

The sacking of the INPE director prompted criticism from environmental groups.

"Bolsonaro knows that his government is primarily responsible for the current destruction of the Amazon. The dismissal of the director of INPE is nothing more than an act of revenge against those who show the truth," said Marcio Astrini from Greenpeace.