The “paleolithic diet” is based on the hypothesis that eating the same food groups as our Stone Age ancestors – such as cultivated plants and unprocessed meats – suppresses appetite. But new research led by Imperial College London in the UK finds this may not be the case.
According to the background of the study, the diets of ancestral human populations incorporated higher levels of indigestible plant material, compared with modern-day diets, which tend to be high in fat and sugar.
Past research has suggested that one of the reasons there has been such an increase in obesity is that the mechanisms behind appetite suppression in humans have evolved to adapt to a higher intake of plant material than what is found in present-day diets.
The researchers explain that when plant fibers are fermented by gut bacteria, this produces short-chain fatty acids (SCFAs). These SCFAs trigger appetite-suppressing hormones, known as peptide YY (PYY) and glucagon-like-peptide-1 (GLP-1).
According to the investigators, these findings suggest the idea that a paleo diet suppresses appetite is “flawed.” In essence, they believe high-fiber, plant-based diets do not increase SCFA production or reduce appetite.
“We found that diet does play a major role in affecting gut bacteria and the production of a hormone that suppresses appetite but not in the direction predicted by the ancestral diet hypothesis. Also, bacterial products were correlated with hormone release that were different from those normally thought to play this role.”
Source: Medical News Today.