Being obese in combination with being tall creates a potential fatal medical condition that isn’t as likely in a shorter but obese individual.You can’t change your height, but you can change your body fat percentage. The conclusion that being tall and obese may increase risk of blood clots is reported in Arteriosclerosis, Thrombosis and Vascular Biology: Journal of the American Heart Association (2010).

So now we have yet one more reason to stop passing off excess body fat as “big bones” in a tall person.

Obesity in and of itself is actually a well-known risk factor for DVT: deep vein thrombosis. A DVT or part of a DVT can break loose and get into the lungs, causing a fatal pulmonary embolism.

Obesity is also an established risk for a pulmonary embolism. DVT and pulmonary embolism are collectively known as venous thromboembolism (VTE).

The report says that VTE risk is 5.28 times higher in obese and tall men; 2.57 times higher in normal-weight and tall males (at least 5′ 11.7″); and 2.11 times greater in obese but short men.

How signicant was this risk increase in being both tall and obese? The report says it’s comparable to other risk factors including oral contraceptive use and pregnancy.

What about women? The risk was 2.77 times higher in obese and tall; 1.83 times higher in obese and short; and for women over 5’6″ and normal weight, there was no increased VTE risk.

Senior study author Sigrid K. Braekkan, Ph.D., says that there actually may be a risk in “very tall” women, but there weren’t enough available for the study.

The researchers have ideas as to why this association exists between DVT, PE and being tall with obesity.

“In tall people the blood must be pumped a longer distance by the calf-muscle pump,” Braekkan explains, “which may cause reduced flow in the legs and thereby raise the risk of clotting.”

This was no small study; 26,714 men and women were tracked for an average of 12.5 years (between 1994 and 2007). During that time there were 461 VTEs.

Obesity creates increased abdominal pressure, which is believed to undermine the ability of the calf-muscle pump to return blood from the legs.

Obesity also causes persistent low-grade inflammation, which may make blood more prone to clotting.

Being tall does not make it any more difficult to reduce body fat percentage. Thus, tall individuals should never use their height as an excuse for being “big” or “large framed,” when in actuality, they are carrying excess body fat.