Strategies to help you follow an FCS diet

Familial chylomicronemia syndrome (FCS) is a rare genetic disorder characterized by extremely high levels of triglycerides circulating in the blood, sometimes ten times the normal amount.

The most common complication of FCS is pancreatitis, inflammation in the pancreas. These blockages are caused by chylomicrons, which are large packages of triglycerides that help transport these fats throughout the body. When chylomicrons block blood flow in the pancreas, it triggers an inflammatory response that damages cells. Episodes of pancreatitis can be severe, and in some cases, life threatening.

FCS can also cause failure to thrive in infants, as well as symptoms that affect a person’s blood, skin, gastrointestinal system, nervous system, and mental health.

Most cases of FCS occur due to genetic mutations that impair the body’s ability to produce an enzyme called lipoprotein lipase (LPL). The body needs this enzyme to break down triglycerides that are circulating in the blood into components that can move into cells for storage and later use. When there is not enough functioning LPL, high amounts of triglycerides remain in the blood. Some cases are caused by other mutations that impair the body’s ability to make proteins that LPL depends on to break down fat.

Standard cholesterol-lowering medications are ineffective at treating FCS, because these medications rely on functioning LPL and/or dependent proteins in order to work. In recent years, several drugs that lower triglycerides in people with FCS have become available, and new therapies are under development.

A strict, low-fat diet is the main treatment

Even with medications and therapies, the main treatment for FCS is following a strict and extremely low-fat diet. People must also avoid alcohol, sugary foods, and processed foods.

This diet requires restriction of all sources of dietary fat, including obvious choices like cooking oils, fatty meats, and full-fat dairy products. It also requires restrictions on foods containing healthy fats, like nuts, seeds, avocado, olives, coconut, and fatty fish.

Different people have higher or lower triglyceride levels. The amount of dietary fat that can be tolerated varies between individuals. You will need to work with a healthcare provider to carefully determine your own tolerance levels, guidelines, and nutritional needs. A healthcare team may prescribe nutritional supplements. Infants require specialized formula.

Following these individual dietary guidelines as closely as possible is critical to avoiding complications and managing FCS.

Strategies to support adherence to an FCS diet

Adhering to this type of extremely low-fat diet is challenging. Planning, measuring, and tracking every ingredient requires time, energy, and emotional labor. Planning ahead and having the right social support can make a difference.

The following are some strategies that may help.

Planning meals and snacks

• Have detailed guidelines from your healthcare team. This includes specific targets for daily fat intake, guidance on reading food labels, and how to calculate the fat content of meals. Ask questions if anything is unclear.
• Meal prep. This can help you avoid situations where you have to make last-minute food decisions.
• Always have low-fat snacks available, including options you can take with you when you are away from home and might miss a meal.
• In addition to tracking what you eat, keep track of recipes and foods you enjoy. Making the same recipe again (and keeping track of the fat content) can save you time. A list of foods and meals also gives you a place to start when you’re planning what to eat next.

Social support

• FCS can be especially challenging when away from home, traveling, and attending social gatherings.
• Prepare and practice how to explain your dietary needs to friends, family members, and anyone you may be sharing meals with. This is also essential if you will be communicating with restaurant or kitchen staff.
• Share low-fat meals with friends and family. Planning and preparation can help the people in your life better understand FCS.
• If you are caring for a child with FCS, involve them in meal planning and preparation. This can help them develop important skills for managing the condition.
• Try to meet and connect with other people who are living with FCS. Look for support groups and online communities.

Work with your healthcare team

• If you’re struggling to follow your dietary guidelines, be honest with your healthcare team. They are there to help you find solutions.
• Consider working with a counselor, social worker, or mental health professional, who can help you find strategies for managing the emotional and mental stress of living with FCS.

Remember, for questions about a diagnosis of FCS, treatment for FCS, and dietary guidelines for FCS, your best source of information will be your healthcare providers.