The amount of calories consumed by people around the world has gone up, but as you have seen this is not the case in all parts of the world. However, the average calorie intake even for the poorest countries, the LICs, has gone above UN safe values. Values in HICs are well above what is required for human well-being.
One of the main reasons for the increase in the amount of food we consume is the rise in global population. As global population and rates of consumption increase there is a need to increase water, food and energy supplies, but to do so in a sustainable manner to meet the needs of all people. The world population crossed 7 billion in 2011, this puts increasing pressure upon resources. In addition, the rates of population growth are not the same around the world. In Africa for instance, population is growing at 2.6% a year, this makes it very difficult to provide a secure food supply for everyone.
Many countries across the world are developing rapidly. In the Newly Emerging Economies (NEEs) such as China or India are becoming wealthier and so are the people that live there. This is allowing a change in the diet of people who live in those countries. It has been observed that the amount of meat consumed in those countries has gone up as development improves. In 1980 people in China consumed just 12kg of meat per person per year, by 2015 this had risen to almost 60kg. This is problematic as approximately 7kg of grain are needed to produce just 1kg of beef, and a typical meat eater needs 2.5 times the amount of land than a vegetarian. This means that people in NEEs need more land and more food produced to meet the needs of their new lifestyles.