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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.

AMS
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

7 Comments

  1. Very often, low fat diets are also low in carbohydrates, relative to the dieter’s previous intake. The only way you can be sure it’s the calorie restriction and not the carbs would be to maintain the same amount of carbohydrates in the low fat diet as the person was eating before they began dieting (cut the fats, but not the number of grams of carbs).

    I guess those carbs would also have to have the same amount of fibre during the diet as before the diet, since fibre content affects the way carbs are processed by the body, and could affect liver health and fat loss or gain.

    Do you know what the carb content of the low-fat diet was? How did it compare to the pre-diet carb content? How did it compare to the low-carb diet in terms of grams of carbs per day?

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  2. If it’s the weight/fat loss that improved the fatty liver condition, it’s not whether the diet itself is sustainable in the long run that matters, it’s whether the weight loss itself is sustainable. From most studies, for approximately 95% of dieters, that’s not sustainable. So, if these people with fatty liver lose weight, improve that condition, and gain the weight back (or more, which has happened more often than not), does the fatty liver condition return? If it does, losing weight to improve that condition sets them up for yo-yo dieting, which could have worse effects on their health than having fatty liver.

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  3. This is an interesting study & appears to be good news in that it may allow people to select the method that is most appealing to the individual (either low-carb or low-fat). To comment on vesta44’s post about the diet being sustainable, I want to point out that the study reports an energy restricted diet of -30%. For people eating 2500 calories pre-diet, that takes them to 1750 calories per day, which is an appropriate intake for many individuals.

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  4. This is a really interesting study in light of some of the “information” that is given to patient at bariactric surgery centres in Ontario.

    Patients are told that “optifast” is needed for them to shrink there livers before surgery, that regular dieting won’t do that. That they have to spend $$$ to buy optifast from the clinic.

    I think someone is padding their profits with lies…..

    CNC

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  5. This is a very interesting study. However, I’m not convinced that the macronutrient composition of the diet does not matter. For sure, weight loss induced by calorie restriction is responsible for the observed effect. But, do we see a similar effect without weight loss by changing macronutrient composition of the diet? If not, than someone can claim that only calories matter. Otherwise, we cannot say that.
    I’m convinced that macronutrients do matter as they don’t share pathways to be metabolized and thus don’t have the same effect on metabolism, lipid profile…. Nonetheless, the effect of either low carbohydrate or low fat diet, without weight loss, may have a smaller effect on fat liver content. Thus, when combined to a calorie restriction, their effects might be diluted by the one of weight loss.

    MEL

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  6. Hi,tank you for your websites my meme is mehdi ,l lives in Iran, I have (nafld)please tell me I how meny minute travel or walking in my treadmel ?

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  7. I was 300 lbs at age 22; lost it with bad fad diets, have maintained my wt between 140-170 ever since (age 56). I have chronic pain so when I don’t have pain medication or are vomiting due to migraines, I am not exercising. 95% of the time I eat a very low fat, high fiber diet and have added protein the last couple of years. Diagnosed with non-alcoholic fatty liver with a dilated common bile duct (not due to tumors or stones). Is it the yo-yoing up and down the 140-170 that has caused it? I do not have diabetes or continuous high blood pressure and no heart problems with a low cholesterol. Or is it due to the 12 medications I take a day?

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