Obesity: the theory of the economical gene to test the facts – factual

The theory of the economical genotype called into question

In 1962, a doctor named James V. Consequently, Neel proposed an idea that was to mark research on obesity and diabetes: the theory of economical genotype. In addition, He thought that. Similarly, in ancient times when famines were frequent, individuals capable of easily storing fat had an advantage: they survived better and more effectively transmitted their genes to the next generation. Therefore, These genes. In addition, formerly useful, would have become unsuitable in modern societies characterized by food abundance and sedentary lifestyle, preparing populations for a famine that would never come and contribute to the explosion of obesity and type 2 diabetes.

To support his economical genotype theory, James V. Similarly, Neel was much inspired by the observation of the Pima Indians living in the Arizona desert. formerly hunter-gatherers and today confronted with very obesity: theory economical gene test high levels of obesity and type 2 diabetes after a rapid transition to Western lifestyle.

Study in more than 800. 000 participants from 7 ethnic groups
David Meyre, professor of biochemistry and molecular biology at the Faculty of Medicine of the University of
Lorraine, health medicine biology pole, hospital practitioner in the service of biochemistry and molecular biology of the
Chru de Nancy, and director of the Nutrition, Genetics and Environmental Risk Exposure – Laboratory Director –
Ngere (University of Lorraine, CHRU de Nancy, Inserm), and Sandra El Kouche, a doctoral student wished
bring new elements concerning the theory of the economical genotype, ardently debated for more than
60 ans.
They used a database bringing together exomes. genomes of more than 800,000 participants from 7
Ethnic groups: Europeans, Latin American, South Asian, East Asians, Africans, Middle East
and Jews Ashkénazes.
They focused on 65 genes linked to rare. severe forms of obesity associated with disorders
development (syndromic), and 8 genes involved in obesity: theory economical gene test monogenic obesity, a form of hereditary obesity
linked to anomalies in hunger regulation circuits.

The theory of invalidated economical genotype
The observations of the researchers suggest that part of the genes of syndromic obesity present
negative natural selection signatures (that is. mutations negatively impacting the function of
proteins are eliminated or “purged” populations at each generation). On the other hand, the obesity genes
monogenic present neither a negative signature nor a positive signature of natural selection. THE
researcher also excluded the possibility of a balanced natural selection. namely signatures of
Alternately positive or negative selection depending on the geographical and environmental context. These
Results invalidate the hypothesis of Doctor James V. Neel on the economical genotype, at least in the 7 groups
Ethnic studied. These forms of obesity would therefore not come from an ancient adaptation to famines.

Conclusions
This study sheds light on the reasons why some people are more sensitive than others to obesity. She
also shows that the genetic heritage obesity: theory economical gene test of obesity varies according to ethnic origins.
But above all, it can help better treat certain rare forms of obesity. Indeed, specific drugs
already exist for some of these genetic cases.

And after?
This study will allow the Ngere researcher to deepen their research among populations
living in desert. island areas and historically subject to recurring food shortages
and severe (e.g. Indian Pima, Bedouins of desert areas, inhabitants of peaceful islands). And how, conversely,
Food abundance over several generations could shape our genome.

Consult the article: https://authors.elsevier.com/sd/article/S0026-0495(25)0022-7