Jeudi 24 septembre 2020

Genetics : tendency or fate ?

TRUE : Some types of obesity are strongly influenced by genetics.

  • A child whose parents are obese has a risk of obesity three times higher than a child having two thin parents. When only one parent is obese, the child has a risk of 40 % of becoming obese and if both parents are, the risk becomes 80 % ! It falls down to 10 % if both parents are thin.
  • This hereditary predestination to obesity is characterized by an increase of metabolic capacity; the organism manages to build fat with a minimum of food and is able to save it, using it up parsimoniously. It is likely that this genetic characteristic was an advantage for our ancestors; small food consumers, those who benefited greatly from very little, would presumably survive better during famine periods than individuals wasting calories. But during periods of abundance, this high metabolic capacity ends up in an excessive storage of fat.

FALSE : If we have an unfavorable heredity, being slim and staying slim are impossible.

Being genetically inclined to gain weight does not mean that we can not be slim and stay like that. It means we will need to pay particular attention to the way we eat, to the calories we burn and to all the situations which could lead us to eat more than necessary.

Genes express themselves mostly when they interact with the external environment. For instance, in sedentary and over eating conditions, individuals genetically inclined will develop overweight. Among individuals that are predisposed and individuals that are not, the external environment being the same (sedentary and over eating), the genes being different, it is the gene-environment interaction that will produce different effects on genetically different individuals. Although we cannot act on the genes, we do have however full latitude to act on our environment (fight against being sedentary, alimentation, psychological problems, etc.)

Photo by the NASA

  • Dernière mise à jour: 19/11/15 16:53