Ancestral diets, also known as “paleo” diets, do not produce a higher level of appetite suppression based on the high fiber and plant composition of these diets. This is the conclusion reached by a study of gut microbes, appetite suppression, and diet conducted by Gary Frost and colleagues at Imperial College London in the United Kingdom. The research was made public in the May 20, 2014, edition of the journal mBio®.
The basis of the “paleo” diet is the assumption that our ancient ancestors consumed a diet high in plants and plant fiber. This dietary preference is thought to have originated in the most ancient of human ancestors. The weight suppression associated with a diet high in fiber is thought to be a genetic inheritance.
The researchers compared the appetite suppression potential of a high-starch diet to a high-fiber diet by exposing vegetarian humans and gelada baboons, the only modern primate to eat mainly grasses, to predigested potato diets and predigested grass diets. The production of appetite suppressing hormones is thought to be initiated by the presence of short-chain fatty acids in the colon. A “paleo” diet is promoted as increasing the levels of appetite suppressing hormones in humans.
Both humans and baboons produced more short-chain fatty acids when they consumed the high-starch potato diet. Similar studies with mice produced the same results. The appetite reduction claims of “paleo” diets are not biologically or chemically sound.
The researchers did find that appetite suppression hormone release did increase with increased consumption of the amino acids isoleucine and valine found in meat. The increase in appetite suppression was much greater than any documented by the presence of short-chain fatty acids in the colon. The researchers conclude that high-fiber diets alone are not sufficient to produce a simplistic cure for the obesity epidemic.
The “paleo” diet assumes that human genetic content has not been altered appreciably since man’s earliest ancestors. This concept is not biologically or evolutionarily sound. As the earliest men developed, they incorporated meat into their diet. Genetic changes due to the increased consumption of meat by ancient human ancestors changed human biology. Most “paleo” diets include large amounts of meat. A reliance on high-fiber is not justified as an appetite suppressant but meat is.