In most countries, average body height and body size is increasing and more needs to be eaten to maintain the higher weight.
Even if both BMI and height were to remain constant, global calorie requirements would still increase by more than 60 per cent by 2100 because of population growth, said the team from the University of Gottingen in Germany in a paper published in the journal PLOS ONE.
The development economist Professor Stephan Klasen and his then doctoral Lutz Depenbusch have designed a scenario to investigate how calorie intake could develop between 2010 and 2100.
Earlier changes in the Netherlands and Mexico were used as a benchmark.
"The developments in these countries are very pronounced," says Depenbusch, "but they do represent a realistic scenario."
With rising BMI, as observed in Mexico, and increasing height, as seen in the Netherlands, there would be a further increase in calorie intake by more than 18 per cent.
This means, the increase in global calorie requirements between 2010 and 2100 would be one third larger, reaching a total increase of nearly 80 per cent, said the researchers.
If global food production does not meet this increased need, this problem will not be controlled by a corresponding decrease in BMI.
While richer people will be able to maintain their eating habits, the poor would suffer greatly from higher prices due to increased demand.
"This would lead to increased consumption of cheap food, often rich in calories but poor in nutrients," said Depenbusch.
"As a result, body weight among the poor would continue to rise alongside malnutrition and poorer health outcomes."
( With inputs from IANS )