The question of how long you should wait between your last meal and when you go to bed has been kicked around for many years. Is it really even an issue? Could a late-night snacking habit contribute to poor health? Turns out the answer is a definite, “Yes,” because eating too close to bedtime on a regular basis can potentially lead to physiological problems down the road of your life. Therefore, taking action to break this bad habit could pay dividends in the form of a healthier you.

What is the best “last meal sleep gap”?

This concept of the last meal gap refers to the time in between your last meal (or consumption of more than a little bit of food) and the time you go to sleep at night.

Evidence-based research supports a direct correlation between eating too close to bedtime and quality of sleep in healthy people. These and other research findings have led to a consensus recommendation among healthcare professionals: refrain from eating for at least three hours before bedtime. In other words, maintain a 3-hour last meal gap.

Why is late-night snacking bad for me?

Here are some of the principal health issues that could prove detrimental, long-term, if an individual fails to kick the late-night eating habit and does not adhere, consistently, to a 3-hour last meal gap:

Digestive issues and poor sleep quality

If your body doesn’t have an adequate amount of time to allow digestion to occur in an upright position, so food can move from the stomach into the small intestine (potentially reducing involuntary disturbances that could occur when horizontal), unpleasant and unhealthy conditions such as acid reflux and heartburn can result.  Regardless of whether a person regularly experiences heartburn or reflux, heavy meals too close to bedtime can leave anyone feeling queasy as digestive motility slows when you are sleeping.

Disturbances in circadian rhythm patterns and metabolic dysfunction

Eating late at night can prevent the body from powering down, interfering with the body’s circadian rhythm — the internal mechanism or “clock” that tells your body when to rest and modulates many other physiological processes. As explained in the article, What’s the connection between sleep and weight loss?, metabolic dysfunction can occur when circadian rhythm is interrupted, leading to insulin resistance, lower levels of energy expenditure, and dysregulation of appetite. If food is consumed earlier in the evening, it is not only digested better, but chances are that sleep quality will be better and you will wake up more energized. For more information on the link between good quality sleep and metabolic health, be sure to read Why sleep matters for your metabolic health.

Potential weight management difficulties

Late-night eating may predispose individuals to weight gain through the intake of higher total calories. There is a biological reason that many people crave typically unhealthy foods (chips, pizza, cookies) as late-night snacks. Researchers have suggested that our internal clock (circadian rhythm) causes us to crave sweet, starchy, and/or salty foods in the evening as an energy preservation method. 

Some foods and beverages that contribute to poor quality sleep when consumed with dinner or as late-night snacks may include: 

• Spicy and acidic (citrus, tomatoes) foods, which can trigger heartburn
• Alcohol, which interferes with the natural sleep cycle, causing fragmented and disrupted sleep
• Soda, energy drinks, coffee, tea, and chocolate — which all contain caffeine
• Heavy foods (fried, cheesy, or meat-based dishes), which are more difficult to digest
• Sweets, which contribute to poor sleep quality as they cause blood sugar to rise, triggering insulin to be secreted to convert the sugar to energy 

Development of metabolic syndrome

Late-night meals and snacks have been linked to metabolic syndrome, a group of risk factors linked to the development of heart disease and type 2 diabetes. 

Best way to measure "last meal sleep gap"

The January AI app seamlessly measures your last meal sleep gap for you as part of its "Recharge" section. The Recharge section focuses on tracking your fasting period, sleep duration and last meal sleep gap, and it automatically gets tracked every day via connecting to your activity/sleep tracker (like your Oura Ring), and when you log your meals directly in the January app. The app will provide you with helpful insights to better your health, and nudge you each day to make healthier, smarter decisions. Learn more about the January app here.

Special situations: When to consider altering the 3-hour last meal gap recommendation

While a 3-hour last meal sleep gap is a consistent recommendation for sleep quality, in some individuals a protein-rich small healthy snack may be beneficial for muscle protein synthesis and boosting cardiometabolic health. (Learn more about healthy snack options: What are the best snacks for diabetics? ) 

When making any significant dietary changes, especially if you have a particular medical condition, it’s always best to first consult with your medical provider or nutritionist. 

Key takeaways

Eating too close to bedtime is a behavior that leads to cravings for unhealthy foods, triggers indigestion, contributes to disruption of sleep, and increases your risk for cardiometabolic issues. So it’s truly an unhealthy habit. On the other hand, consuming consistent-sized meals throughout the day and monitoring your nightly food habits to coincide with the recommended 3-hour last meal sleep gap will set the stage for an overall healthier lifestyle. If you’re finding it tough to adhere to this recommendation, see our guide: 5 proven ways to make habits stick.