There are all sorts of good reasons to avoid becoming fat. Excess fat tissue is linked to an increased risk of all the common diseases of aging, and correlates well with a shorter life expectancy and higher lifetime medical expenditures. Fat tissue creates higher levels of chronic inflammation and alters the signaling environment in the body, causing a wide range of changes. Here is another of them:

Having too much body fat makes arteries become stiff after middle age, a new study has revealed. In young people, blood vessels appear to be able to compensate for the effects of obesity. But after middle age, this adaptability is lost, and arteries become progressively stiffer as body fat rises - potentially increasing the risk of dying from cardiovascular disease. The researchers suggest that the harmful effects of body fat may be related to the total number of years that a person is overweight in adulthood. Further research is needed to find out when the effects of obesity lead to irreversible damage to the heart and arteries, they said.

Researchers [scanned] 200 volunteers to measure the speed of blood flow in the aorta, the biggest artery in the body. Blood travels more quickly in stiff vessels than in healthy elastic vessels, so this allowed them to work out how stiff the walls of the aorta were using an MRI scanner. In young adults, those with more body fat had less stiff arteries. However, after the age of 50 increasing body fat was associated with stiffer arteries in both men and women. Body fat percentage, which can be estimated by passing a small electric current through the body, was more closely linked with artery stiffness than body mass index, which is based just on weight and height.

"We don't know for sure how body fat makes arteries stiffer, but we do know that certain metabolic products in the blood may progressively damage the elastic fibres in our blood vessels. Understanding these processes might help us to prevent the harmful effects of obesity."

Link: http://www.sciencedaily.com/releases/2013/05/130515085333.htm

Source:
http://www.fightaging.org/archives/2013/05/excess-body-fat-hardens-arteries.php