Carbon dioxide in carbonated beverages induces ghrelin release and increased food consumption in male rats: Implications on the onset of obesity

Obes Res Clin Pract. 2017 Sep-Oct;11(5):534-543. doi: 10.1016/j.orcp.2017.02.001. Epub 2017 Feb 20.


Background: The dangerous health risks associated with obesity makes it a very serious public health issue. Numerous studies verified a correlation between the increase in obesity and the parallel increase in soft drink consumption among world populations. The effects of one main component in soft drinks namely the carbon dioxide gas has not been studied thoroughly in any previous research.

Methods: Male rats were subjected to different categories of drinks and evaluated for over a year. Stomach ex vivo experiments were undertaken to evaluate the amount of ghrelin upon different beverage treatments. Moreover, 20 male students were tested for their ghrelin levels after ingestion of different beverages.

Results: Here, we show that rats consuming gaseous beverages over a period of around 1 year gain weight at a faster rate than controls on regular degassed carbonated beverage or tap water. This is due to elevated levels of the hunger hormone ghrelin and thus greater food intake in rats drinking carbonated drinks compared to control rats. Moreover, an increase in liver lipid accumulation of rats treated with gaseous drinks is shown opposed to control rats treated with degassed beverage or tap water. In a parallel study, the levels of ghrelin hormone were increased in 20 healthy human males upon drinking carbonated beverages compared to controls.

Conclusions: These results implicate a major role for carbon dioxide gas in soft drinks in inducing weight gain and the onset of obesity via ghrelin release and stimulation of the hunger response in male mammals.

Keywords: Carbon dioxide; Carbonated beverages; Food consumption; Ghrelin; Weight gain.

MeSH terms

  • Adolescent
  • Adult
  • Animals
  • Body Mass Index
  • Carbon Dioxide / administration & dosage
  • Carbon Dioxide / adverse effects*
  • Carbonated Beverages*
  • Case-Control Studies
  • Ghrelin / blood*
  • Humans
  • Hunger
  • Male
  • Obesity / diagnosis*
  • Obesity / etiology
  • Rats
  • Rats, Sprague-Dawley
  • Weight Gain
  • Young Adult


  • Ghrelin
  • Carbon Dioxide