I'm documenting every part of the BBC Documentary 'Why are Thin People Not Fat' while I watch it. Don't forget to watch part 1, part 2, and part 3!

It's a quiet Sunday morning, little one is in bed, home is pretty clean: time to watch part 4 of 'Why Are Skinny People Not Fat!'

Why do some people gain weight easily, and others don't?

Is staying thin simply a matter of self-control, will-power, controling eating behavior?
Some people apparently persistently eat more than they really have to. This video shows an interesting experiment with young kids. They've all just had lunch, when they're offered a plate of snacks. Most kids started to eat - even though they were fairly full. Other children simply pushed the plate away and started coloring. Kids didn't copy each other's behavior, some simply ate when they were full, while others didn't.
This experiment shows that behavior patterns are already pretty well established in young children.

Do you eat when you're not hungry?

Chances are if you have a tendency to eat snacks while full as a toddler - you'll behave the same way as an adult. It seems that the size of our appetite has a genetic basis.
For some people, resisting all the foods that are offered -- is simple. Where as for other people, it's a lot harder. Most of the people in the experiment in this video don't eat when they're not hungry. But since they have to eat for this experiment, no matter whether they are hungry or not, it'll be very interesting to see if they are actually going to gain weight now!

Here it is:

I'm documenting every part of the BBC Documentary 'Why are Thin People Not Fat' while I watch it. Don't forget to watch part 1 and part 2!

Wow. It's so awesome to hear a doctor say humans have a biological determined natural weight, that varies from person to person. "Our bodies do their best to maintain that weight: whether it's fat or thin."
That doesn't mean you can't influence your body shape, but your body will constantly try to bring you back to whatever your normal body weight is. And that is different for every person!

Dr. Allison at the University of Alabama at Birmingham says our 'normal' body weight is shaped even before we are born. Factors such as how old your mother was when you were born, and the amount of calories taken during pregnancy play a role.

This video covers week one of the experiment -- boy, what a ridiculous amount of food these folks had to eat...I'd almost feel bad for them! It's super interesting to see big differences in weight gain at the very start of this experiment. Can't wait to see part 4!

I'm documenting every part of the BBC Documentary 'Why are Thin People Not Fat' while I watch it. Don't forget to watch part 1.

Wow, I learned some CRAZY things in this episode!
Fat people used to be the survivors of society, having fat is a good thing, and...I probably would have never survived if I was born a few centuries ago. Phew, I'm glad it's 2012 ;) Watch the second episode here, and read my comments below :)

Why fat is good

Inside fat tissue, apparently, the fat cells have oil droplets stored -- which can be converted into energy if the body needs it. So, your fat is your body's built-in emergency storage system. The more fat you have, the longer you can go without eating. Apparently, one very obese man once lasted a year without food! (just watch the video, it's amazing).But the average person can last about a month without food.

Survival of the fattest

When food wasn't always readily available, people who were chubbier were more likely to survive, and pass on that gene to their children -- which could explain why a large part of the current population has a tendency to gain weight easily.

Survival of the thinnest

Fat storage used to help in survival,but that has changed over time. Nowadays, it's not needed to go without food for several days or even weeks. Nowadays, people who exercise and eat well are more likely to live longer.