There are many lessons to be learned from the stories of people on TLC's "My 600-lb Life." The show illustrates how obesity impairs many aspects of brain functioning and cognition even after weight loss. Patients of bariatric surgeon Dr. Younan Nowzaradan demonstrate immaturity, impulsive behavior, broken limit switches and poor problem-solving skills. Shedding weight in gastric bypass helps but many still struggle with decision-making skills. It almost seems like obesity causes brain damage. Good case studies are half-ton Sean Milliken who lost a quarter ton, Melissa Morris and Christina Phillips who each lost over 500 pounds.

Obesity causes brain damage?

The University of Cambridge found that excessive weight interferes with the brain's white matter, which relays messages across different regions. Brain cells don't regenerate in the same way other body cells do, so the effects of morbid obesity could be permanent. Christina Phillips shed a remarkable amount of weight after gastric bypass but is still haunted by fears of weight gain. She has trouble making good food choices and sometimes goes days without eating. She can't trust that she is loved in her new relationship. These eating disorders are no different than overeating in that her limit switches don't work.

Sean Milliken--intellectual disability from childhood obesity?

At 26, Sean lost a massive 500 pounds but is still disabled at over 500 pounds. Many commenters have noted that of all the immaturity of the patients on "My 600-lb Life" Sean demonstrates a marked childishness, even after weight loss. Sean grew up obese due to an abusive dad and compensating mom.

Did obesitycripple his ability to think rationally? Will this be permanent?

Melissa Morris brings poor food choices to new generation?

At nearly 700 pounds, Melissa made a decision to lose weight so she might have children. She now has three kids but doesn't feed them much differently than she fed herself. Morris has gained some weight back and blames the kid food she keeps on hand.

She finds the junk food tempting and doesn't seem to realize that she could use what she's learned about healthy food choices in feeding her children. They could be healthier and avoid the obesity that so plagued her.

Can brain damage be healed?

All these cases show that obesity harms cognition. But are these people doomed to suffering forever with brain damage or is it reversible? If they continue the great work they began, keep making good choices, sever unhealthy relationships, and allow themselves to feel good about their progress, there is every hope. The more you use your brain the stronger it gets. Here's more on Christina's story.