Castro's destruction of nutrition.

Rice is the staple of Cuban food. Cubans where no bread eaters. they ate rice.

"After WW2 imported rice was difficult to obtain and costly, so Cuban
farmers had an incentive to grow rice. In 1949 Cuba produced 10 percent of
domestic consumption. In 1960, the year after Castro came to power, the
Cuban rice harvest was 400,000 metric toms, making Cuba for the first time
self-sufficient in rice. During the decade of the fifties, Cuban producers
had successfully adopted the latest methods of rice farming employed in
Louisiana and Texas. From the point of technological expertise, rice

production outstripped that of any other branch of Cuban agriculture; and in
terms of money value, rice became one of Cuba's major crops.

By 1962, with Cuban agriculture socialized, the rice yield was reduced by
50%. The same year, as has already been noted, the rationing of foodstuffs
was introduced, with the rice ration set at 6 pounds per person per month.
That lowered per capita consumption by two thirds.

More over, for  low-income Cubans, for whom rice formed amore substantial
part of their diet, the reduction was even greater."

M. Halperin, Return to Havana, Vanderbilt University Press, Nashville, 1994,

A well functioning free market ensured that from a shortage in 1949 break
even was achieved by 1960. Castro ruined the industry by 1962. In two years
50% of the annual need in rice were no longer met.

In 1966 the rice ration was again reduced by half to 3 ponds per person per
month. that is down from 18 to 3 ponds since the start of the dictatorship.

The reason was: the deal that Castro himself had made with China on the
supply of rice fell through when Castro didn't deliver the promised support
in their "polemic" with the SU.

(for details on the rice Crisis and the Cuba - China quarrel see: M.
Halperin, Taming of Fidel Castro, Berkeley: University of California Press,
1981, p. 195-207.)

"Thus in 1965, Cuban rice production had dwindled to 50,000 tons..."

M. Halperin, Return to Havana, Vanderbilt University Press, Nashville, 1994,

Why did Castro need to reduce rice productions even further: to grow more
sugar to reach his (foolish) goal of 10 million tons of sugar  in 1970.

He never made it, but destroyed the production of a staple food while at it.

Gross incompetence. Criminal negligence.

At the end of 1989 the rice ration was 5 pounds. Down from an average
consumption of 18 pounds before the revolution.

Last I saw that is still the same outside Havana with a 20% larger ration of
6 pounds in Havana.