Fatty Liver Disease


What is fatty liver?
What is Non-alcoholic fatty liver disease (NAFLD)?
What can be considered excessive alcohol consumption?
What causes fatty liver disease?
How do we define 'overweight' and 'obese'?
Does the size of your waist matter?
How does fat get into the liver?
What is the natural evolution of the disease?
What is NASH?
Can children develop fatty liver disease?
What are the symptoms of fatty liver disease?
How is fatty liver disease diagnosed?
What is the treatment?
A healthy lifestyle
Can fatty liver disease be prevented?

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What is a fatty liver?
A fatty liver is the result of the excess fat in liver cells. Fatty tissue slowly builds up in the liver when a person’s diet exceeds the amount of fat his or her body can handle. A person has a fatty liver when fat makes up at least 5% of the liver 1. Simple fatty liver can be a completely benign condition and usually does not lead to liver damage. However, once there is a buildup of simple fat, the liver becomes vulnerable to further injury, which may result in inflammation and scarring of the liver 2.

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What is Non-alcoholic fatty liver disease (NAFLD)?
NAFLD is a progressive complex of liver disease which starts with fat accumulation in the liver without excessive alcohol consumption. It is strongly associated with metabolic syndrome (obesity + insulin resistance + dyslipidemia)3

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What can be considered excessive alcohol consumption?
More than 2 drinks per day for women and 3 drinks per day for men 3 
One drink is equivalent to:
341 ml (12 oz.) bottle of 5% alcohol beer, cider or cooler
142 ml (5 oz.) glass of 12% alcohol wine
43 ml (1.5 oz.) serving of 40% spirits 4

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Non-Alcoholic Fatty Liver Disease illustration used with permission from MayoClinic.com. All rights reserved

Fatty liver disease video
Click on the image below to watch a short video on fatty liver disease (presented in partnership with the British Liver Trust)



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What causes fatty liver disease?
The most common cause of fatty liver disease in Canada is obesity. Whereas several decades ago obesity was not very common, according to current statistics more than 50% of Canadians are overweight. It is estimated that 75% of obese individuals are at risk of developing a simple fatty liver. Up to 23% of obese individuals are at risk of developing fatty liver with inflammation.

Besides obesity, nutritional causes of fatty liver disease are:
  • starvation and protein malnutrition,
  • long term use of total parenteral nutrition (a feeding procedure that involves infusing nutrients directly into the blood stream),
  • intestinal bypass surgery for obesity,
  • rapid weight loss.

Certain conditions often accompany and may contribute to fatty liver disease:
  • diabetes mellitus,
  • hyperlipidemia (elevated lipids in the blood),
  • insulin resistance and high blood pressure.

Other causes include:
  • genetic factors,
  • drugs and chemicals such as alcohol, corticosteroids, tetracycline and carbon tetrachloride.
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How do we define “Overweight” and “Obese”?
Although many people feel they could lose some weight, few would consider themselves obese. A widely-used measure to define “overweight” and “obese” is the Body Mass Index (BMI). A BMI is a calculation based on your height and weight that gives a number that reflects either a healthy or unhealthy weight. The BMI is  endorsed by World Health Organization (WHO) and by Public Health Agency of Canada 6.

You can use the following formula to calculate your BMI: BMI = weight in kilograms divided by (height in metres)2

Example: for someone who is 1.70 meters tall who weighs 80 kilograms: BMI  = 80 divided by 1.70 x 1.70 = 27.7 

BMI Classification 

<18.5  Underweight
18.5 to 24.9  Normal Weight
25.0 to 29.9  Overweight
30.0 to 34.9 Obese I
35.0 to 39.0 Obese II
BMI ≥ 40 Obese III

Different ethnic groups may differ slightly - for example, in Asian populations the healthy BMI is lower, ranging from 18 -23.
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Does the size of your waist matter?
Excess abdominal fat is associated with fatty liver disease and other health risks such as diabetes9. Waist measurements - which differ according to gender - are used to identify the health risks associated with excess abdominal fat: For men, health risks increase if your waist circumference is more than 102 cm (40 in.). For women, the risks increase if your waist circumference is more than 88 cm (35 in.)11.

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How does fat get into the liver?
Fat from a person’s diet is usually metabolized by the liver and other tissues. If the amount of fat exceeds what is required by the body, fat is stored in the fatty tissue. Other reasons for accumulation of fat in the liver could be the transfer of fat from other parts of the body or the inability of the liver to change it into a form that can be eliminated.

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What is the natural evolution of the disease?
These liver disorders are generally chronic but progressive. Simple presence of fat is what happens with the majority of patients with NAFLD, and most of them have a benign clinical course. However, if let untreated, NAFLD may progress to more advanced disease, such as Non-alcoholic steatohepatitis (NASH),  which may evolve to fibrosis, cirrhosis,  and liver cancer (HCC) in a few cases2
The disease progression usually takes decades, and depends of a combination of genetic and environmental factors 13. The relative importance of these factors is variable in different groups and depends of lifestyle choices and other factors such as the intestinal micro-biome (gut microbial community).  The components related to the progression of the disease require further studies 3.

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What is NASH?
NASH stands for Non-Alcoholic steatohepatitis and it represents the more severe end of the spectrum of non-alcoholic fatty liver disease.  Steatohepatitis means fatty liver with inflammation, in other words, ongoing damage similar to alcoholic liver disease but in this case it occurs in people who do not drink alcohol or drink minimally 13.

NASH differs from the simple accumulation of fat in the liver, which is a completely benign condition. Up to 20% of adults with NASH develop cirrhosis and up to 11% may experience liver-related deaths. Many individuals develop chronic liver failure and require liver transplantation. The prevalence of NASH is 2-6% in the general population.

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Can children develop fatty liver disease?
Fatty liver disease is the most common cause of liver disease in children. Almost 10% of children may have NAFLD, due in large part to an alarming increase in childhood obesity 15 . It is estimated that one in 10 Canadian children is overweight - a number that has almost tripled in the last decade. Fatty liver disease affects almost 3% of children and 22 – 53% of obese children. Fatty liver disease can be found in children as young as four years of age. The chances of developing NAFLD increases with age, thus is more common in adolescents. Furthermore, more boys present the disease than girls (2:1)16 

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What are the symptoms of fatty liver disease?
In general, people with fatty liver disease have no symptoms. However, some people report discomfort in the abdomen at the level of the liver, fatigue, a general feeling of being unwell and vague discomfort.
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How is fatty liver disease diagnosed?
Fatty liver disease is usually suspected in patients who have abnormal liver tests (ALT, AST, GGT) or have an enlarged liver 18. An ultrasound of the liver can suggest the presence of a fatty liver. Other diagnose methods may be used such as computed tomography (CT), proton magnetic resonance spectroscopy (H-MRS), and magnetic resonance imaging (MRI) 13. In some cases, your doctor may advise a liver biopsy, a procedure where the physician inserts a needle into the liver and extracts a sample tissue, which is then examined under a microscope.

What is the treatment?
Currently, there is no medication proven to effectively treat fatty liver disease, if the main causes are related to obesity, diabetes and dyslipidemia.17. The treatment is based in lifestyle modification, weight loss, and physical activity in order to reduce the amount of fat in the liver. Patients who are obese are advised to achieve a gradual and sustained weight loss through proper nutrition and exercise.  The weight loss should be around 5-10% of body weigh to reduce steatosis and above 10% to improve the inflammation in patients with NASH13.
Patients with diabetes and high lipids in their blood have to improve their sugar control and lower lipids levels. Usually, a low fat, low calorie diet is recommended along with insulin or medications to lower blood sugar in people with diabetes20.
Some studies have shown beneficial effects of coffee. The caffeine intake loweres the incidence of abnormal liver enzymes. It is also associated with liver protection. There is an inverse association between coffee consumption and NAFLD12.  Other studies suggested  the use of Vit E it may improve the steatosis and reduce the inflammation1


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Choose to lead a healthy lifestyle.
The treatment of fatty liver disease is related to the cause. At this time, it is not possible to predict which patients will develop NASH. Once there is a buildup of simple fat however, the liver becomes vulnerable to further injury, which may result in liver inflammation and scarring (NASH).

Patients who are obese are advised to achieve a gradual and sustained weight loss through proper nutrition and exercise. Patients with diabetes and high lipids in their blood have to improve their sugar control and lower lipids levels. Usually, a low fat, low calorie diet is recommended along with insulin or medications to lower blood sugar in people with diabetes.

For patients with NASH who are not overweight and not diabetic, a low fat diet is often recommended. It is also recommended that people avoid drinking alcohol since it can cause and contribute to fatty liver disease. Patients with fatty liver disease should see their primary healthcare providers on a regular basis.

Currently, there is no medication proven to effectively treat fatty liver disease. Since it is now such a common condition, it has raised a lot of interest in the scientific community. There are now a number of clinical trials looking at various treatments of fatty liver disease.

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Can fatty liver disease be prevented?
By choosing a healthy life style, you may prevent obesity - the number one reason for fatty liver disease. Please remember that a healthy diet and exercise are important components of any weight-loss regimen. The following are some suggestions for preventing fatty liver disease5:
  • Choose to lead a healthy lifestyle.
  • If you are overweight, strive for a gradual and sustained weight loss.
  • Eat a well-balanced diet that is low in saturated fats and high in fibre.
  • Minimize sugar consumption, reduce the intake of fried food
  • Introduce exercise into your routine, at least four times a week. You can enjoy walking, swimming, gardening, stretching.
  • Avoid alcohol.

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For more helpful tips on healthy choices, download our LIVERight: Liver-Healthy Shopping Guide.

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20. Takei Y. Treatment of non-alcoholic fatty liver disease. J Gastroenterol Hepatol. 2013;28 Suppl 4:79-80. doi:10.1111/jgh.12242.

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