It really drove home how laborious and time consuming is the study of metabolic pathways. We know that a severely reduced calorie diet can prolong life in many organisms (possibly humans), but finding out why this is takes decades in animal models, let alone human trials.

Many of the most significant medical breakthroughs were accidents (which gave rise to Pasteur's quip – 'chance favours the prepared mind'). Many predictions are made by people caught up in the excitement surrounding a discovery.

A good example of progress thwarted is the use of smallpox as an indicator of our maturity to rid the world of infectious diseases.
Before its pathogenesis was understood, people found that exposing a healthy person to the fluid from the abscess of a smallpox victim would infect them with a less virulent version and increase their chance of survival (although the fatality rate was still high using this method).
The realisation that milk maids exposed to cow pox had immunity to smallpox further improved the understanding and when it was finally eradicated in 1979 we thought we could conquer any disease given enough scientific understanding and international co-operation. Predictions were made about the end of infectious diseases.
Unfortunately, smallpox was relatively well behaved and suffered little antigenic shift over the course of decades which meant that the already effective vaccine would continue to work till its eradication.
Diseases like malaria are caused by the plasmodium eukaryote which changes its surface proteins very regularly to defeat vaccines.
Also, international effort have not been so concerted with other diseases, especially governments which embrace HIV denialists and amoral vitamin pedlars rampant in parts of Africa.

As with any financial advice, Past Performance is No Guarantee of Future results.

Still, the best bet at the moment is to eat around 800 calories a day in the hope that the extra years that it might prolong your life enough to for an accidental discovery of a cure for the terminal illness of being born.