CONFUSED..!! There are people who eats all the JUNK and oily foods but still have a lean and perfect body. while there are some "like me" to whom a single chocolate cookie is enough to gain weight.. Any thought...??

Because they're at the gym every single day of the week or outside doing something physical. Or maybe because you eat a single chocolate bar, but 5 pancakes, a whole chicken, 2 cans of Chef Boyardee, a large pizza, and 2  plates of pasta before the day is over.

The same can be said for me except that my cholesterol level remains at around 97. That's in American.

Ya. If someone has good genetics, they'll be healthy naturally & they don't have to work as hard or eat as well. If someone has bad genetics, it doesn't really matter what they do (healthy or not). They're not going to be very healthy & it'll get worse as they get older.

Life depends on luck, you just have to be born with the right genes, the right parents & the right place. If you happen to have good genes, good parents & born in a good place that's not poor, then you'll be more likely to be ok. But if you don't, your life will be more likely to be much worse & shorter. Not always of course. Each generation gets affected twice as much as the one before. My mom had depression so I had depression/ptsd too, only twice as bad.

I got screwed genetically & I was born in a very poor area. So of course my life would be much worse than most humans.

Because these people might have a fast metabolism.

Because they have a fast metabolism.  The world is an unfair place, but all you can do is to continue to eat healthy.  That includes not starving yourself.  The more healthy your diet is, the faster your metabolism is.  Of course, it's all right to sneak a treat every so often.... >:-)

Not everyone's matabalisum is the same.