Obesity can increase damage to the liver caused by drinking alcohol, a new study shows, and in women can double the risk of liver disease. Read the full story

Even Moderate Obesity Shortens Life Expectancy

According to new analysis of 57 studies that involved a total of nearly a million subjects, researchers have found that being obese can shorten a person’s average lifespan by two to four years, and by up to eight to ten years for the very obese.

The study was primarily done to see how body mass index, or BMI, effects mortality.

BMI is calculated by multiplying a person’s weight in pounds times 703, and dividing that sum by their height in inches squared. A BMI between 30 to 35 is considered moderately obese and a BMI of 40-50 is considered morbidly obese.

Though there is controversy of the use of measuring one’s health with BMI – for example, some weightlifters have high BMIs due to their muscle mass – it is still a useful tool for assessing the extent that fat can cause health problems.

Study participants were 46 years old, with an average BMI of 25 when the study began in 1979, and were mostly from North America and Western Europe.

During the follow-up period, which averaged eight years, mortality was found to be lowest in the men and women who maintained a BMI between 22.5 and 25. However, with every additional 5 BMI points, the mortality risk rose by 30%. The highest BMI deaths were due to cardiovascular disease, diabetes, kidney and liver disease, and even some cancers.

In presenting these findings, researchers hope that people may become more motivated to prevent weight gain or attempt to lose weight in efforts to extend their life.

A new study shows that weight loss surgery may resolve obesity-related, nonalcoholic fatty liver disease.

That’s the finding of a team of researchers at the University of Texas Medical Branch in Galveston, led by Dr. Gagan Sood, in a report published in the December 2008 issue of Clinical Gastroenterology and Hepatology.

Nonalcoholic fatty liver disease comes in two varieties: steatosis, or fatty liver, which is characterized by the accumulation of fat within the liver, and nonalcoholic steatohepatitis – NASH, for short – which is known for causing liver inflammation and in some cases the formation of fibrous tissue within the liver.

Both varieties pose risks to a patient’s health, but NASH is the more serious of the two – over time, it can turn into cirrhosis or even liver cancer. The bad news is that about 95% of morbidly obese people have some form of nonalcoholic fatty liver disease.

But, the good news is that bariatric surgery can substantially improve markers of metabolic syndrome, which is often associated with nonalcoholic fatty liver disease. And, recent studies have demonstrated that obesity-related liver disease improves significantly after bariatric surgery.

In the meta-study at UT, nonalcoholic fatty liver disease was completely resolved in more than 80% of the patients after their bariatric surgery.

Three out of four in the survey also saw significant improvement in their liver fibrosis, and 70% had complete resolution of nonalcoholic steatohepatitis.

It’s worth noting, however, that the study involved less than 1000 patients, and the researchers –while hopeful – warn that only a large-scale controlled clinical study can conclusively prove or disprove a link between weight loss surgery and a reversal of obesity-related liver disease.