This morning, I read an article written by William Saletan which is talking about the causes to obesity. At first, he said that he used to think genetics are more important than environment, but later, he realized the relationship between nature and nurture is not that simple. In his article, he uses some control groups and experiments to support the ideas that although genetics take the majority percentage of the obesity, environment such as diet and lifestyle is controlling it.
I find this article is quite attractive because as a girl, keeping slim is always one of the most significant parts in life. Personally speaking, I agree with author. As for me, I admit that genetics determine what kind of physique we have, but lifestyle and eating habits can take it over. Around us, there are a lot of examples. For instance, I have 5 schoolmates who were extremely fat before, but become slim now. According to my observation, the most members of their families are as fat as them, so obese might to be blame. But why can they take over the genetics? The reasons are healthy diet and regular exercises. What I can see from the examples is that sometimes genetics are not invincible. Sometimes environmental factors can control them. Just as author said, just because something is genetically caused doesn't mean it can't be behaviorally controlled. (http://www.slate.com/articles/health_and_science/human_nature/2008/02/fat_chance.2.html)
What I want to say is that when comparing nature and nurture, there is no absoluteness. Sometimes acquired disposition gains the upper hand to change what genetics want us to be, but sometimes, it can't.
Source from the website http://www.slate.com/articles/health_and_science/human_nature/2008/02/fat_chance.html
I agree with what you said about how the environment can control the genetics. Being born fat won't mean that your gonna be fat for the rest of your life. Being fat is a choice that can be decided depending on what you do like what you said about going on a diet and so on.