he following text and photos are from Oprah.com and a recent show on the human body.

From the show Inside the Human Body

Dr. Mehmet Oz is one of the most respected surgeons in the world, as well as host of Second Opinion on the Discovery Health Channel. Today, Dr. Oz brought a selection of real healthy and damaged organs to demonstrate what goes on inside the human body. If you overeat, smoke or drink too much, you may be surprised to see what you're doing to your body.

This should put your dieting into perspective—this container holds five pounds of human body fat! Imagine carrying five or ten of these on your back. That's what you're doing to your body when you gain weight.

The reason we get fat, Dr. Oz explained, is because our ancestors survived because they could store fat. In modern society, with no problems of food shortage, we're taking in more fat than we need to survive. By controlling your weight, Dr. Oz says, you can add years to your life.

The healthy heart (left) is very supple, firm and poetic, according to Dr. Oz. 

The unhealthy heart (right) is larger and paler. The lighter spot in the middle indicates that this person had a heart attack. That scarred vessel was unable to bring blood to the heart, and the damage can be seen on the inside.

Once an artery is closed, it doesn't heal, which is a devastating problem, Dr. Oz says. While medicine has gotten better at curing heart attacks, damage is still done after a heart attack, creating an epidemic of heart failure.

Dr. Oz took a cross-section of a healthy liver (left) and an unhealthy liver (middle) to better demonstrate the differences.

The healthy liver is soft, smooth and supple. The unhealthy liver contains little nodules, which is an example of cirrhosis, caused by drinking too much alcohol. The liver serves to process all the materials you bring into your body, which it can't do if it's diseased.

The worst thing that can happen to your liver is cancer (right). When your liver becomes damaged, and the body is continually trying to repair itself, it can lead to cancer.

According to the American Diabetes Association, more than 18 million people in the United States have diabetes. Dr. Oz says that although diabetes can be managed, it's important to pay the right kind of attention to the disease. "One of the problems with diabetes is that you feel normal, so you don't take things seriously," he says.

What diabetics can't see is how blood vessels can shrink, causing harm to the kidneys. On the left is a normal kidney; on the right, a damaged kidney. The good news is that Type 2 diabetes can be prevented through exercise and diet.