The human body is quite resilient. Cutting our daily calorie intake by half will only decrease the body weight by one quarter. But reducing it beyond that threshold is dangerous - first, the body burns up its fat stores before it dips into the protein pantry in our muscles and organs. Then the immune system weakens and we are highly vulnerable to disease.
Children under five are least likely to survive. Roughly four hundred major famines have been recorded through human history.
Man’s struggle with food started early. In parts of Europe, unusual amounts of rain fell in the early 14th century, submerging many crops. Desperately needing to fill their aching bellies, farmers slowly began eating into the seed for next season's plantings. The food supply dropped and prices increased.
Society was in crisis: Wheat prices tripled, shortage rose eightfold. The poor could not buy food and in some places there was simply no food available. The poor were dying in huge numbers… The food that was available was of very low quality - bread contained pigeon and pig droppings and animals that had died of disease were eaten, causing outbreaks of disease among humans.
Worldwide, the United Nations Food and Agriculture Organization (FAO) estimates that 842 million people were undernourished in 1999 to 2001 - 10 million of whom were in industrialised countries, 34 million in countries in transition, and 798 million in developing countries. The report stated: 'The numbers of undernourished continue to rise in sub-Saharan Africa and in the Near East and North Africa.'
The United Nations Millennium Ecosystem Assessment, published early in 2005, claimed that more than two billion people still lived in the dry regions of the world. They suffer more than any other part of the population from problems such as malnutrition, infant mortality, and diseases related to contaminated or insufficient water.
Areas such as sub-Saharan Africa are among those where natural services are most threatened by human impacts. Bucking the trend of the rest of the world, the amount of food produced for each person living in this region has actually been going down.
In 2015, six per cent of the world population (412 million people) had eaten less than 2 200 kcal per day while sub-Saharan Africa, are the most undernourished. No matter how great human advances, they have not spread current food supplies evenly across the world like a neatly buttered slice of toast.
The second half of the twentieth century has produced enough food to fill every stomach on the planet. But, towards the close of the century, most of it was being eaten by Western Europe, Japan and North America, where half the world's food was eaten by only a quarter of the world's population.
It didn't help that the hungrier nations were producing crops for export to ensure the industrial countries had a bigger and more varied diet. During this time, the 'domestic cat in the United States ate more meat than most people living in Africa and Latin America', writes historian Clive Ponting.
So while many in the First World literally eat themselves into an early grave with adult-onset diabetes, heart disease and other obesity-related illnesses, elsewhere in the world a child dies from hunger-related causes every eight seconds. Sub-Saharan Africa, after decades of post-colonial strife, war and governmental mismanagement, remains one of the most nutritionally deficient regions of the world. Mostly, states the United Nations, because of 'its lack of political will to tackle poverty'.
In March 2003, well over 15 million people in Zimbabwe, Zambia, Malawi, Lesotho, Swaziland and Mozambique faced immediate shortages due to a combination of unfavourable weather conditions, specifically droughts and flooding; poor macroeconomic management; and political turmoil, resulting in the worst regional food security crisis in the past decade.