Nutrition 7 MIN READ

How meal timings affect sleep quality

Due to our busy schedules, we do not have any fixed meal timings, but does that affect the quality of our sleep?

Written by Sonia

Oct 02, 2021
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Evidence from a John Hopkins study suggests that your brain is as active when asleep as it is when awake. So what really is going on when you get some shut-eye?

timings affect weightgain


  • The quantity and quality of sleep vary based on what meals you consume and when you consume them,
  • When people are more tired during the day, they end up eating more throughout the day, which adds to their weight over time,
  • Food consumed closer to the sleeping period, such as dinner and a late-night snack, have been known to negatively impact sleep quality.

While the research is in the preliminary stages and sleep continues to remain a mystery, studies show that sleep re-energizes the body’s cells, supports learning and memory, and clears waste from the brain. It even plays a key role in regulating mood, appetite, and libido. One of the ways that the quantity and the quality of sleep varies is through what meals you consume and when you consume them. A study published in 2012 in The Journal of Clinical Endocrinology & Metabolism found that when people are more tired during the day, they end up eating more, which adds to their weight over time.

Caffine and sugary snacks/drinks, consumed over a long period of time, can affect the quality of your sleep. According to the American Sleep Association, even high-fat diets can affect the way you sleep. A study conducted at the University of Adelaide suggests that men who eat a high-fat diet are more likely to sleep poorly, experience daytime sleepiness, and suffer from sleep apnea. While there’s no set diet that can help you sleep better, there are tiny changes that you can make to achieve a more satisfying snooze.

Meal timings

Studies have concluded that eating at night has a direct correlation with negative effects on the quality of sleep in healthy people. Food consumed closer to the sleeping period, such as dinner and a late-night snack, has been known to negatively impact sleep quality. Many nutritionists and studies recommend that it is better to wait three hours between the last meal of your day and your bedtime to ensure the best quality of sleep. The gap allows the food in your stomach to move into your small intestine. This delay could potentially reduce any involuntary disturbances one might face in their sleep, such as acid reflux and heartburn, etc.

Meal timings – weight loss and gain

Weight gain is predominantly associated with the quality and quantity of food, linking everything to what we consume. Type 2 diabetes and heart disease are often only spoken about in the context of calorie intake and calorie expenditure through exercise. However, there’s growing evidence suggesting that when you consume meals is also important. The timing of our meals and their effects on our body’s response dates back a long time. Ancient Chinese medics held the belief that energy flows around our bodies according to the sun’s movements. They believed that our mealtimes should be in rhythm with the trajectory of the sun. 

  1. 7- 9 am was dedicated to the stomach, which meant this was the time when the largest meal of the day had to be consumed.
  2. 9 -11 am centred around the pancreas and the spleen.
  3. 11 am -1 pm was focused on the heart.
  4. 5 pm-7 pm was considered dinner time, and a light meal was recommended. This time also revolved around the kidney.
meal timings affect

Circadian rhythm and meal timings

When you look at newer research, it’s not far off from what our ancestors believed. Our sleep-wake cycle is regulated by something known as the circadian rhythm, a natural, internal process that repeats approximately every 24 hours. It is, in essence, our biological clock. It allows organisms to anticipate changes in the light-dark environment, between day and night and also regulates and influences sleep, arousal, feeding, and metabolism.

The circadian rhythm is tethered to the rotation of the earth. Today, we’re able to understand better than ever how it affects our metabolic health. Circadian eating, meaning eating early, has been shown to have better results for weight loss, with participants having early and large breakfasts in comparison to participants who had heavy dinners.

sleep productive guide 1

A molecular clock that modulates the timing of every physiological process like the secretion of hormones and neurotransmitters, the immune cell activity, and the time you feel sleepy, alert, or depressed, keeps ticking within every cell of the body. These timekeepers work in harmony with each other and with the time of the day. This synchronicity is achieved through the suprachiasmatic nucleus (SCN), a small speckle of brain tissue. It functions in tandem with photoreceptive retinal ganglion cells (ipRGCs), light-receptive cells behind the eye.

The purpose of these clocks is to foresee and prepare for consistent events in the environment. Varied biochemical reactions are at work at different times of day, facilitating our internal organs to switch gears and recover. “Unless we have access to light, we struggle to stay awake and eat at the wrong time,” asserts Satchin Panda, a circadian biologist. This explains the discomfort and digestive problems arising from jet lag. The timings of our meals can also turn the hands of the clocks in the liver and digestive organs, even though the timepieces in our brain cells are unchanged.

Melatonin and metabolism

Can Melatonin make you gain weight?

Melatonin is a type of hormone known for controlling our sleep cycle in the circadian rhythm. It’s a signal to our bodies that it is time to go to bed. It is also involved in the way our metabolism works. Increased levels of melatonin at dinner time can impair glucose tolerance. That means that eating late, when our bodies are tuned to being asleep and not awake, can have detrimental effects on our metabolic health. According to various studies, having a late dinner or eating late at night is associated with increased risks of obesity, dyslipidemia, hyperglycemia, and metabolic syndrome. Many other studies focused on eating late at night show an increased risk of diabetes as well because of nocturnal hypoglycemia.

In fact, an interesting 12-week experimental study of overweight/obese women with metabolic syndrome split into two weight loss groups found that the subjects with the highest consumption of calories during dinner had greater insulin resistance than those with the highest caloric intake during breakfast. It suggested that consuming fewer calories at dinner was beneficial and might be a useful aide to the management of metabolic syndrome.

Meal timing for deep sleep


While there might be contradictory beliefs about whether to skip breakfast or not, one thing is certain—having a large breakfast and a small dinner is more beneficial than its reverse, especially for weight loss. 


People who eat lunch late – after 3 pm, tend to lose less weight than early lunch eaters – before 3 pm, despite having similar profiles in terms of age, appetite hormones, energy intake, and sleep duration.


Having a small dinner 3 hours before bedtime is proven to be good for sleep, reducing the chances of reflux and heartburn, which in turn gives your body enough time to rest and recover. Early dinner also helps sync and maximise the circadian rhythm. It avoids clashing with elevating melatonin, which hampers efficient glucose metabolism. 


While there are many variables that still need more research, such as genetics and how they would affect individuals differently when it comes to meal timings, there is strong evidence that meal timings affect weight loss, weight gain, and quality of sleep. Keeping the available data in mind, each individual should decide how they would like to regulate their meals to get the best sleep they possibly can. A sleep doctor or a general physician can also be consulted, in case of an underlying condition and depending on the severity of the problem.

Disclaimer: The contents of this article are for general information and educational purposes only. It neither provides any medical advice nor intends to substitute professional medical opinion on the treatment, diagnosis, prevention or alleviation of any disease, disorder or disability. Always consult with your doctor or qualified healthcare professional about your health condition and/or concerns before undertaking a new healthcare regimen including making any dietary or lifestyle changes.


  1. High caloric intake at breakfast vs. dinner differentially influences weight loss of overweight and obese women
  2. Meal frequency and timing in health and disease
  3. Association of night eating habits with metabolic syndrome and its components: a longitudinal study
  4. Acute melatonin administration in humans impairs glucose tolerance in both the morning and evening
  5. Circadian topology of metabolism

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