Fatty liver disease, also called Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), formerly known as Non-Alcoholic Fatty Liver Disease (NAFLD), is becoming more common in young people today. In the past, this condition was mostly seen in older adults, especially those who drank alcohol heavily or had obesity. However, recently, doctors have noticed that more and more young people are getting it. This is concerning because fatty liver disease can lead to serious health problems, like liver damage and other diseases, if not treated early. Understanding why this is happening can help us find ways to prevent it and protect young people's health.

Unhealthy Diets and Poor Eating Habits - Fatty liver disease in younger people can be primarily attributed to poor eating habits. The modern diet includes processed food, fast food, sugary drinks, and snacks high in fat and sugar. Such foods are low in nutrients but high in calories which creates a disproportional relationship between energy consumed and energy burned. Fructose, which is a type of sugar found in soft drinks and many processed foods, is harmful to one's body because when it is consumed in large amounts, the liver has to work hard to get rid of it. Unlike glucose, fructose has to be broken down in the liver, which is the only place it is processed. This excess fructose is transformed into fatty acids in the liver and later these fatty acids are stored in the liver as triglycerides. The accumulation of triglycerides leads to fat deposition in the liver as hepatic steatosis, commonly known as fatty liver.

Lack of exercise and sedentary lifestyle - Another big reason for the rise in fatty liver disease among young people is a lack of physical activity. Today, many young people spend long hours sitting at desks, using phones, or playing video games. They often don't get enough exercise, which is needed to burn off the extra calories and fat in the body. Without enough physical activity, the liver becomes less efficient at processing fat, which leads to fat accumulation in the liver. This lack of exercise also contributes to obesity. When people carry extra weight, especially around the belly, it can cause more fat to collect in the liver. Even if someone is not obese but spends most of their time sitting, their liver can still become fatty due to the lack of movement and exercise.

Obesity, insulin resistance, and metabolic dysfunction - Obesity is one of the most important risk factors for fatty liver disease. Individuals who are overweight, particularly those with a higher amount of abdominal or visceral fat, are more likely to develop fatty liver disease. Visceral fat releases free fatty acids into the bloodstream, which can overwhelm the liver, causing it to store these fats. This fat accumulation triggers inflammation in the liver, leading to cell injury and fibrosis (scarring). Moreover, obesity often leads to insulin resistance, a condition where the body's cells become less sensitive to insulin. This forces the pancreas to produce more insulin to compensate. Excess insulin can cause the liver to store more fat, worsening the fatty liver condition. Insulin resistance is also linked to hyperglycemia (elevated blood sugar levels), which further contributes to liver fat storage and increased risk of developing Type 2 diabetes alongside fatty liver disease.

Genetics and family history - Genetics, or the genes we inherit from our parents, also play a role in whether someone will develop fatty liver disease. Some people have genes that make them more likely to store fat in their liver, even if they don't have obesity or diabetes. For example, a specific gene called PNPLA3 has been found to increase the risk of fatty liver in certain people. If someone has a family history of liver disease or obesity, they may be at a higher risk of developing fatty liver disease, even if they lead a relatively healthy lifestyle.

Stress, mental health, and unhealthy habits - Issues with mental health can also lead to conditions like fatty liver disease. Stress, in particular, is a common problem faced by many youngsters today due to high expectations in work, studies, and personal life. Stress causes the body to release high quantities of the cortisol hormone that is responsible for stress. Cortisol causes the body to store fat, particularly around the midsection, which greatly increases risks of liver disease. Furthermore, people under stress often resort to binge eating, consuming comfort foods, or increasingly drinking soda, all of which can have bad effects on the liver's health.

Alcohol and smoking - Fatty liver disease, which stem from other lifestyle choices rather than drinking alcohol for younger individuals, may worsen due to alcohol consumption. Even drinking small amounts of alcohol can be stressful to the liver, and for those with fatty liver disease, consuming alcohol could further increase damage. Smoking is yet another unhealthy lifestyle that has a negative impact on one's liver. The smoke from cigarettes contains many harmful substances that lead to inflammation of the liver which makes fatty liver disease a lot more severe, even for people who do not consume alcohol.

Hormonal imbalances and certain medications - An imbalance of certain hormones such as those triggered by issues with the thyroid can also cause fatty liver disease. The thyroid is responsible for regulating metabolism and when the system fails, there is the possibility of accumulation of body weight and fat and this includes at the liver. Certain medications can also contribute to fatty liver disease. For example, long-term use of medications like steroids, some antidepressants, and drugs used for treating mental health conditions can cause weight gain and fat accumulation in the liver.

What happens if fatty liver disease is left untreated?
Not taking care of fatty liver disease may lead one to severe complicated health issues. Overtime, inflammation of the liver leads to scarring which can advance into metabolic dysfunction-associated steatohepatitis (MASH), formerly known as NASH, in effect, the liver is already damaged, and there is severe intermediate damage, and may, in some cases, lead to complete liver failure. If one does not seek help to treat MASH, fibrosis (or scarring of the liver) may progress into cirrhosis, liver cancer, and organ failure. Fatty liver disease also has an increased risk of diabetes, cardiac problems, and hypertension as potential accompanying complications. So, even if someone is young, the long-term effects of fatty liver disease can significantly impact their health.

Prevention and treatment - Fatty liver disease is largely preventable and reversible if caught early. The most important steps in preventing or managing fatty liver disease are:

• Healthy diet: Eating a balanced, calorie-restricted diet full of fruits, vegetables, whole grains, and lean proteins, while limiting sugary drinks, fast food, and unhealthy fats, can help protect the liver. Black coffee consumption (without added sugar or cream) may also provide liver-protective benefits.
• Exercise: Regular moderate aerobic exercise and strength training performed daily helps the body burn fat, maintain a healthy weight, and improve liver function.
• Stress management: Managing stress through relaxation techniques, exercise, and good sleep can help reduce the risk of fatty liver disease.
• Weight loss: If overweight, losing even a small amount of weight can reduce liver fat and improve liver health. Even in people with normal weight, reducing body weight by just 3 percent can help reverse fatty liver disease.
• Avoiding alcohol and smoking: Limiting alcohol and avoiding smoking are essential for keeping the liver healthy.

If fatty liver disease is diagnosed, lifestyle changes like diet and exercise can often reverse the condition. In more severe cases, medication may be necessary, but lifestyle changes remain the most important treatment.

Dr. Vishnu Girish, Consultant - Liver Transplant & Hepatology, Sahyadri Super Speciality Hospital, Pune