When you have narcolepsy, your brain doesn’t manage your wake-sleep cycle properly. Scientists are still studying the causes. But they believe one factor is a substance in your brain called hypocretin. It helps carry signals that regulate sleep.
The best-known symptoms of narcolepsy are extreme tiredness during the day and disturbed sleep at night. Others may include:
- Sudden loss of muscle control when you’re awake, called cataplexy
- Inability to move when you’re falling asleep or waking up
- Hallucinations
- Suddenly falling asleep without warning
The effects of narcolepsy on your body go beyond sleep. Among other issues, narcolepsy has been linked to weight gain and obesity.
Impact on Weight
People with narcolepsy tend to have a higher BMI (body mass index), than those with normal sleep patterns. Studies have found that adults with narcolepsy tend to weigh more than average -- up to 20% more.
Narcolepsy can cause you to put on weight quickly. In one study, children gained as much as 40 pounds within a few months after their narcolepsy symptoms first showed up.
People with narcolepsy have higher rates of:
These are all additional health risks linked to obesity.
What Causes It?
It's not simply a matter of overeating. People with narcolepsy have been found to be prone to weight gain even when they don’t eat more.
Low metabolism may be part of the reason. When you have narcolepsy, your body burns calories more slowly. Some researchers have suggested that daytime sleepiness makes people less active, and so more likely to gain weight.
Studies have shown that lack of sleep can affect what and how you eat. You’re more likely to choose high-calorie foods when you’re tired. People with narcolepsy are at higher risk for eating disorders, especially binge eating and craving certain foods.
Hypocretin -- the substance in your brain that plays a role in narcolepsy -- may also contribute to obesity. It helps regulate appetite and energy use in your body.
Scientists still are untangling how all these things may work together to cause obesity in people with narcolepsy.
The Role of Medication
The impact of many narcolepsy drugs on obesity is hard to gauge.
Some people take prescription stimulants to help fight daytime sleepiness. These drugs would normally decrease your appetite. Others take a type of antidepressant that usually makes you hungrier. Several studies found no difference between the BMIs of people who were on either type of narcolepsy medication and those who weren’t.
The narcolepsy drugs pitolisant (Wakix), and sodium oxybate (Xyrem) have been shown to cause weight loss.
What Can You Do?
Narcolepsy treatment is an important part of managing your weight as well as your sleep. Research shows that getting enough sleep helps you maintain a healthy BMI.
Some of the advice for managing your weight when you have narcolepsy will sound familiar:
The timing of your meals matters. Late lunches and dinners close to bedtime make it harder to lose weight.
Make sure your diet includes enough calcium, magnesium, and vitamins A, C, D, E, and K. Research shows these nutrients are important for sleep.
Are you a night owl? You may want to shift to an earlier wake-sleep routine. Going to bed and waking up late can put you at higher risk for weight gain.
