Obese and overweight people require more fuel to transport them and the food they eat, and the problem will worsen as the population literally swells in size, a team at the London School of Hygiene & Tropical Medicine says.& \. J+ b1 }! k0 K
This adds to food shortages and higher energy prices, the school's researchers Phil Edwards and Ian Roberts wrote in the journal Lancet on Friday.& \$ g' y3 E% v5 f3 H
"We are all becoming heavier and it is a global responsibility," Edwards said in a telephone interview. "Obesity is a key part of the big picture."
5 g, ~, o# P h. d! A At least 400 million adults worldwide are obese. The World Health Organization (WHO) projects by 2015, 2.3 billion adults will be overweight and more than 700 million will be obese.! V3 M+ L2 v% D3 r3 ~. n
In their model, the researchers pegged 40 percent of the global population as obese with a body mass index of near 30. Many nations are fast approaching or have surpassed this level, Edwards said.
3 t6 d4 A) G% C5 P BMI is a calculation of height to weight, and the normal range is usually considered to be 18 to 25, with more than 25 considered overweight and above 30 obese.; k% l' N! A' }3 P+ E
The researchers found that obese people require 1,680 daily calories to sustain normal energy and another 1,280 calories to maintain daily activities, 18 percent more than someone with a stable BMI.
! I6 o% x6 F3 c" `' N Because thinner people eat less and are more likely to walk than rely on cars, a slimmer population would lower demand for fuel for transportation and for agriculture, Edwards said.
8 {/ T( S3 h4 ?& e5 S: B This is also important because 20 percent of greenhouse gas emissions stem from agriculture, he added.# X( H5 X/ p* }3 S! F
The next step is quantifying how much a heavier population is contributing to climate change, higher fuel prices and food shortages, he added.
/ O$ } g" m4 i& y' @- ]* N. t) { "Promotion of a normal distribution of BMI would reduce the global demand for, and thus the price of, food," Edwards and Roberts wrote. |