As a college professor, I am regularly surrounded by sleep-deprived young adults who sometimes wear their chronic lack of sleep as a badge of honor, comparing notes on who got less shut-eye before a big exam.

But the truth is that a lack of sleep – whether cramming for an exam or burning the candle at both ends for another reason – is counterproductive. Research has clearly shown that adequate sleep helps us to do better at mental tasks and also at committing information to memory, so you can stay sharp. Here are six more reasons to make an early bedtime a priority.

Sleep fights off colds. A study published in the journal JAMA Internal Medicine in April found that people who reported sleeping five hours or less each night were more likely to experience a cold or other infection in the past 30 days. This supports previous studies, including one that purposefully administered the cold virus to participants to see who went on to get sick; the subjects who slept fewer hours were almost three times more likely to develop a cold when compared to those who slept eight or more hours.

Sleep improves exercise. Exercise has been shown to improve the ability to get a good night’s sleep, and better sleep improves workouts. Conversely, research has shown that when you are sleep-deprived, exercise just seems harder, leading to a less intense or shorter workout. Studies of athletes indicate performance in sports may suffer when a person is sleep-deprived, and that recovery takes longer.

Sleep keeps your appetite hormones in check. Your body has hormones that are at work constantly creating feelings of hunger and fullness. Human laboratory studies have shown these hunger hormones – ghrelin, leptin and insulin – are disrupted when sleep is cut short. Additionally, studies have found feelings of hunger increase when subjects are sleep-deprived, and those who haven’t gotten enough rest have a tendency to choose higher-calorie “comfort” foods.

Sleep helps prevent migraines. A study conducted in South Korea had migraine sufferers use a headache-tracking diary on their smartphone to try to identify common migraine triggers. Sleep deprivation and fatigue, along with stress, rounded out the top three identified triggers. Another study published in the journal Headache demonstrated a decrease in migraines when women who were prone to them got more sleep.

Sleep enhances blood sugar control. When healthy young men went without adequate sleep for three nights in a study published in the journal Diabetologia, they ended up with pre-diabetic conditions. Researchers found the free fatty acids were elevated in their blood, which makes it much harder for the body’s insulin to do its job of decreasing blood sugar. Another study on almost 15,000 Korean adults found a link between shorter sleep deprivation and higher blood sugar, especially in men.

Sleep fights obesity. Many observational studies have shown a link between obesity and inadequate sleep in children and adults. This is probably due to a number of factors. To start, sleepy people are less likely to exercise and tend to make poorer eating decisions. However, other factors are likely also at play, such as a sluggish metabolic rate and an increase in food cravings. One study published in the journal Obesity demonstrated a lower morning metabolic rate when subjects were deprived of sleep, while another study from the University of Pennsylvania demonstrated more weight gain in subjects that were put on a sleep deprivation program, when compared to subjects who were allowed to get enough sleep.

So how can you get enough sleep? Start with a regular bedtime schedule and routine, add in exercise during the day, cut down on caffeine after noon, limit nicotine and alcohol, make sure your bedroom is dark, cool and quiet, and seek help from a sleep specialist if needed.