If your countrymen allow you to make it to a "600lbs life" without abject comment, then they have done you a disservice; certainly you're bound to feel more shame and discomfort dealing with being in that state.
Everyone on my mother’s side of the family are obese. Extremely obese. They all told me that it would happen to me due to genetics. They never mentioned their sedentary lifestyles or the packs of cigarettes or the 2 liters of soda they consumed each day.
I was so ashamed of them growing up that I was motivated to never allow myself to become that way.
that's not shame, that is positive reinforcement via negative example.
shame is something put upon you, and not a decision you make on your own.
breaking the cycle you were in is no small feat; please do not misunderstand. what you did was difficult. I would not say that you were shamed into doing it, by what you've said.
I was so ashamed of them growing up that I was motivated to never allow myself to become that way.