Frank Dikotter has a new book out about the Great Leap Forward, Mao's Great Famine: The History of China's Most Devastating Catastrophe.  I haven't read it yet (mine is on order) but early reviews are in.  Here's Jonathan Mirsky:

In brutal fact, between 1959 and 1962, at least forty-three million
Chinese died during the famine [Edgar] Snow didn't bother to see. Most died of
hunger, over two million were executed or were beaten or tortured to
death, the birth rate halved in some places, parents sold their
children, and people dug up the dead and ate them.

The cause of this disaster, the worst ever to befall China
and one of the worst anywhere at any time, was Mao, who, cheered on by
his sycophantic and frightened colleagues, decreed that before long
China's economy must overtake that of the Soviet Union, Britain and even
the US. Mao suggested that 'When there is not enough to eat people
starve to death. It is better to let half of the people die so that the
other half can eat their fill,' and declared that anyone who questioned
his policies was a 'Rightist', a toxic term eventually applied to
thirteen million Party members.

Here is Jonathan Fenby:

…By digging into the records, Dikötter provides a detailed litany of the
degree of suffering the Great Helmsman unleashed and the inhumane manner
in which his acolytes operated. Horrors pile up as he tells of the
spread of collective farms and the vast projects that caused more harm
than good and involved the press-ganging of millions of people into
forced labour. As the pressure mounted to provide the all-powerful state
with more and more output, the use of extreme violence became the norm,
with starvation used as a weapon to punish those who could not keep up
with the work routine demanded of them. The justice system was
abolished. Brutal party cadres ran amok. "It is impossible not to beat
people to death," one county leader said.

Some contemporary Chinese nationalists try to rationalize the Leap as somehow necessary for China's modernization and ascent.  That is rubbish.  It was a totally unnecessary assault on Chinese farmers and citizens.  Dikotter's book reminds us that Mao did vast damage to the country and its people.  The Chairman was a deeply inhumane man and ruler, one whom Mencius would certainly denounce:

"There's plenty of juicy meat in your kitchen and plenty of well-fed horses in  your stable," continued Mencius, "but the people here look hungry, and in the countryside they're starving to death.  You're feeding humans to animals.  Everyone hates to see animals eat each other,and an emperor is the people's father and mother – but if his government feeds people to animals, how can he claim to be the people's father and mother?" (1.1)

We might amend Mencius' words here.  What Mao did was tantamount to feeding people to the Party,  he killed them to maintain the power of the CCP, the institution he led, that gave him  his power, and which carried out the horrible work of the GLF.