Reducing Liver Fat – Does Diet Composition Matter?

Non-alcoholic fatty liver diseases (NAFLD) is one of the most common complications of excess weight and can sometimes lead to cirrhosis and liver failure.

In addition, fatty livers can swell to a size large enough to increase intra-abdominal pressure and obstruct a surgeon’s view during abdominal surgery.

Fortunately, fatty liver disease responds well to weight loss and even a few weeks of caloric restriction can lead to a remarkable decrease in liver size and fat content.

But whether these changes are simply due to caloric restriction or wether there is some advantage of simply reducing carbohydrate or fat content of the diet is not clear.

This question was now addressed in a randomised controlled study by my former colleagues at the Franz Volhard Clinical Research Center, Charité University Medical School, Berlin in a study just published in HEPATOLOGY.

Sven Haufe and colleagues radomised a total of 170 overweight and obese, otherwise healthy subjects to either reduced carbohydrate (n = 84) or reduced fat (n = 86), total energy restricted diet (-30% of energy intake before diet) for six months.

Both hypocaloric diets decreased body weight, total body fat, visceral fat, and intrahepatic lipid content with no differences between diets.

As may be expected, subjects with higher baseline intrahepatic fat lost substantially more (7-fold) liver fat than those with less steatosis.

In contrast, changes in visceral fat mass and insulin sensitivity were similar between subgroups, with low and high baseline intrahepatic lipids.

Therefore, this study clearly demonstrates that a prolonged calorie-restricted diet has the same beneficial effects on liver fat content, irrespective of whether it is low in carbohydrates or low in fats.

This study provides more evidence that when it comes to reducing the complications of obesity, what ultimately counts are calories rather than the actual composition of the diet. This does not mean that some people may find it easier to lose weight by cutting carbs while other find it easier to cut fat.

In the end what counts is whether or not the ‘diet’ is sustainable in the long run and results in better health.

Edmonton, Alberta

Haufe S, Engeli S, Kast P, Böhnke J, Utz W, Haas V, Hermsdorf M, Mähler A, Wiesner S, Birkenfeld AL, Sell H, Otto C, Mehling H, Luft FC, Eckel J, Schulz-Menger J, Boschmann M, & Jordan J (2011). Randomized comparison of reduced fat and reduced carbohydrate hypocaloric diets on intrahepatic fat in overweight and obese human subjects. Hepatology (Baltimore, Md.) PMID: 21400557