The body weight of adopted children shows
no correlation with the body weight of their adoptive parents,
who feed them and teach them how to eat. Their weight does have
an 80 percent correlation with their genetic parents, whom they
have never met.
Identical twins, with the same genes, show a much higher similarity
of body weights than do fraternal twins, who have different genes.
Certain groups of people, such as the Pima Indian tribe in
Arizona, have a very high incidence of severe obesity. They also
have significantly higher rates of diabetes and heart disease
than other ethnic groups.
We probably have a number of genes directly related to weight.
Just as some genes determine eye color or height, others affect
our appetite, our ability to feel full or satisfied, our metabolism,
our fat-storing ability, and even our natural activity levels.
We probably have a number of genes directly related to weight.
Just as some genes determine eye color or height, others affect
our appetite, our ability to feel full or satisfied, our metabolism,
our fat-storing ability, and even our natural activity levels.
Environmental Factors Environmental
and genetic factors are obviously closely intertwined. If
you have a genetic predisposition toward obesity, then the
modern American lifestyle and environment may make controlling
weight more difficult.
Fast food, long days sitting at a desk, and suburban neighborhoods
that require cars all magnify hereditary factors such as metabolism
and efficient fat storage.
