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WHICH IS THE BEST DIET FOR OBESITY-INDUCED LIVER DISEASE?

 Liver disease is very common in obese individuals.  The liver becomes loaded with fat (like everywhere else), and the fat then begins to irritate the liver.  The first indication of this is usually an abnormal blood liver test.  In a significant number of people this will progress over time to chronic liver disease and even liver failure.  A huge number of obese children have fatty livers, and there is concern that many of these children will eventually develop serious liver disease in adulthood.

What is the best dietary treatment for this condition?  Nutrition experts may well tell you that your liver is full of fat because you consumed too much fat, and you should now go onto a low-fat diet. 

However, the scientific evidence does not support this.

For example, scientists looked at the effect of 3 weight-loss treatments on liver abnormalities in obese diabetic adults - an American Diabetes Association low-fat diet (30% fat), a low-glycemic diet (also low-fat), and a Mediterranean diet high in olive oil (45% fat).  Liver tests were measured at 6 and 12 months.  Liver abnormalities decreased on all 3 dietary treatments, but the reduction was most pronounced with the Mediterranean diet.  This was not directly related to the weight loss, indicating that the Mediterranean diet was having an effect beyond it's ability to decrease body weight. 

 One study does not a health policy make -  but it's a good start.  There is also accumulating evidence that a diet containing a lot of soft drinks and fructose (fructose is in sugar and high fructose corn syrup) may irritate the liver.

 If you are obese and have abnormal liver function tests, you will probably need more testing to figure out the cause and to determine the best treatment.  There is no consensus yet in the medical community as to what this should be, and and you should  discuss the options with your physician.  It's not a trivial problem!  In terms of dietary treatment, the Mediterranean diet seems to be an excellent choice.

Reference: Fraser et al.  A modified Mediterranean diet is associated with the greatest reduction in alanine aminotransferase levels in obese type 2 diabetic patients: results of a quasi-randomised controlled trial. Diabetologia 2008;51:1616-1622