Your liver is a true powerhouse of an organ. It has a hand in some of your body’s most crucial regulatory processes, from the digestion and metabolizing of various nutrients to the detoxification of your blood. So, when there’s something wrong with your liver, the consequences can be serious. And unfortunately, a damaged liver may not always emit any overt or obvious signals that something is wrong. That means that major liver issues may go undetected for a long time.
But, as it turns out, one of the most telling indicators of your liver function is actually your body composition, which makes it much easier to keep tabs on your own health! Read on to find out how your body composition impacts your liver function, and how you can use this information to proactively protect your wellbeing.
The liver: what it is and why it matters
Your liver is a large organ that sits in your abdominal cavity, near your stomach, intestines, and kidneys. As a part of the digestive system, your liver plays a huge variety of roles in your body, including:
- Producing bile for digestion
- Metabolizing fat-soluble vitamins
- Processing drugs
- Producing cholesterol
- Regulating carbohydrates and proteins
- Detoxifying blood by removing drugs and other potential toxins
Because it’s an integral factor in so many different bodily processes, your liver’s health directly impacts your overall health. Unfortunately, under certain circumstances, your liver can become prone to conditions and diseases that lessen its ability to function normally, such as nonalcoholic fatty liver disease.
Nonalcoholic fatty liver disease (NAFLD)
As you might be able to guess from the name, nonalcoholic fatty liver disease (or NAFLD for short) is a set of conditions in which excess fat accumulates in your liver. This type of fat accumulation can also occur from excess alcohol consumption, in a disease aptly named “alcohol-related liver disease” (ARLD). But, unlike ARLD, NAFLD can occur in the absence of excessive alcohol consumption, influenced instead by factors like your lifestyle and genetics.
While NAFLD does not always cause symptoms on its own, having it can increase your risk for other serious health issues, such as cardiovascular disease and Type 2 diabetes.
There are two different kinds of NAFLD:
- Nonalcoholic fatty liver (NAFL): People with NAFL have an enlarged liver with excess fat accumulation, but this type of NAFLD comes with minimal inflammation or damage to the liver itself.
- Nonalcoholic steatohepatitis (NASH): People who have this kind of NAFLD can experience inflamed livers. Twenty percent of these patients will progress to cirrhosis (scarring), which can damage the liver itself. These devastating impacts mean that NASH has even been linked to liver cancer and liver failure, and it is highly associated with the necessity for liver transplants.
Generally, people with nonalcoholic fatty liver disease will develop either NAFL or NASH. However, some people with one form of NAFLD may later be diagnosed with the other form.
So, how does fatty liver disease develop in the first place? As it turns out, your body composition plays a big part in it.
How your body composition affects your liver function
Your body is primarily composed of four components: body water, minerals, skeletal muscle mass, and body fat. While all of these factors can have a major impact on your overall metabolic health Two of these factors, your skeletal muscle mass, and your body fat mass, can have a huge impact on your overall metabolic health. In this case, they can also influence how much fat is accumulating in your liver.
Some specific body composition risk factors that can affect your liver function include excess body fat, uneven body fat distribution, and low skeletal muscle mass.
Excess body fat mass
Obesity is one of the biggest body composition risk factors for developing nonalcoholic fatty liver disease and other liver issues.
Under typical circumstances, the dietary fat that you consume breaks down into fatty acids which are then stored primarily in your fat tissue, although small amounts are also stored in your liver. But it’s thought that the high amounts of fat tissue present in obese patients increase the rate at which fatty acids are released into circulation, which then goes on to increase the rate at which the liver accumulates fat. More specifically, researchers have found that increased risk for NAFLD occurs if the total percent body fat exceeds 32.23% in women and 26.73% in men.
Body fat distribution
You don’t necessarily even need to be obese for your body fat to impact your liver health either, because the location in your body that your fat tends to accumulate also matters.
High levels of visceral fat, aka “central adiposity” (or, even more simply, belly fat), seem to play a key role in how your liver is affected by your body composition when compared to other kinds of fat accumulation. For example, one study discovered that, after averaging the weight of its subjects, higher levels of central adiposity were associated with increased instances of fatty liver. Meanwhile, subjects who had more fat stored in lower extremities, such as their legs, were found to have fewer instances of fatty liver.
Low skeletal muscle mass
Your body composition can contribute to liver complications beyond a NAFLD diagnosis. In conjunction with high levels of body fat mass and central adiposity, low levels of skeletal muscle mass can also cause further complications like fibrosis, or scarring of your liver, which can lead to more serious issues like cirrhosis. A cross-sectional 2021 study found that, among 149 participants being treated for nonalcoholic fatty liver disease, instances of liver fibrosis were significantly and inversely associated with skeletal muscle mass, and significantly and positively associated with fat mass, waist-hip ratio, and visceral fat.
There are also some other common risk factors that you could use to predict the health of your liver and its subsequent functioning. While these factors might not necessarily be body composition measurements, they tend to be positively correlated with both metabolic conditions and nonalcoholic fatty liver disease — and both of these can be influenced by body composition.
Take metabolic syndrome, for example. Metabolic syndrome is a cluster of metabolic conditions like high blood sugar, high cholesterol, and abdominal obesity that can increase your risk for developing serious chronic conditions, including heart disease and Type 2 diabetes. Because metabolic syndrome and nonalcoholic fatty liver are both heavily influenced by obesity and other body composition factors, scientists often find an association between the two. For example, one global epidemiological review found that there was a 42.54% association between NAFLD and metabolic syndrome. Interestingly, a fatty liver overproduces both blood sugar and triglycerides, two of the key components found in metabolic syndrome. So, while having metabolic syndrome might not cause fatty liver, or vice versa, having high triglyceride levels and/or blood sugar levels might indicate that it’s time to have your liver checked by a doctor.
In addition to the amount of stored fat tissue in your body, there’s also the fat in your blood to consider, otherwise known as your “triglyceride levels.”
One of your liver’s jobs is to create triglycerides, a form of fat that it releases when your body needs energy. These triglycerides are then delivered to your cells via your bloodstream, where they can provide energy. But, under certain conditions, such as obesity, your body’s ability to process its fats can change, contributing to the accumulation of fat on your liver. In fact, a 2014 study found that, among 168 NAFLD patients, elevated triglyceride levels were the strongest predictor of NAFLD compared to other metabolic issues, including cholesterol and blood glucose levels.
Another risk factor for the fatty liver disease has to do with insulin resistance, which is also associated with obesity and high body fat percentages.
Under typical circumstances, the hormone insulin helps your body store glucose, which is what carbohydrates are broken down into upon digestion in your body. Insulin also suppresses lipolysis, which is the process by which your body breaks down its stored fat for energy. But your cells can become insulin-resistant for a variety of metabolic-related reasons, including regular overconsumption of calories. Unfortunately, some scientists believe that insulin resistance can impact your ability to suppress lipolysis, leading to increased fat storage in your liver instead. Insulin resistance can also promote inflammation, which may further contribute to liver damage.
Assessing your risk
Regular visits with your primary care provider are critical for diagnosing diseases like nonalcoholic fatty liver disease. But, short of ultrasounds, CT scans, and invasive liver biopsies, you can also keep an eye on your risk factors for fatty liver diseases simply by keeping track of your body composition and taking regular blood tests.
- Body composition testing is an easy, non-invasive way to keep an eye on those body composition factors that have been linked to liver function, such as your body fat percentage, skeletal muscle mass, and visceral fat. While body composition testing can’t help you diagnose diseases or conditions, it can certainly help you keep track of your risk for fatty liver and other metabolic conditions — and help you be proactive about monitoring your liver function without involving more expensive or invasive testing methods. The great news here is that if you do experience NAFLD or other liver issues, dietary changes and weight management may be able to help. Researchers have found that high-calorie diets and excessive fructose consumption are often associated with instances of NAFLD, but losing just 5-10% of your total body weight can lead to improvements.
- Blood tests are an invaluable tool for taking a closer look at other risk factors that could be affecting your liver function. For example, triglyceride tests/cholesterol panels and blood sugar tests can provide key insights into your metabolic health and indicate if something more serious is going on that needs to be addressed.
If you do find that either your body composition tests or your blood tests indicate that you may be at a higher risk for developing NAFLD or other liver complications, you can check in with your doctor to ensure that any potential issues are detected in a timely manner.
A healthy liver is critical for an overall healthy body, but you may not always be able to tell that there’s something wrong with this important organ until it is too late. But by monitoring key body composition measurements, you can take a proactive role in managing your risk factors.