Eating just before bed – Risks, Benefits and Considerations

Sleep is a state of physical and mental inactivity, making the person become relatively slow and unaware of the surroundings. It is a homeostatic process maintaining the balance between active and periodic physiological mechanisms in the body essential for physical,  mental and general well being. The quantity and quality of sleep is affected by several behavioral and environmental factors.  Sleep and nutrition are considered as key factors in determining the overall health status of an individual.

Food, diet and nutrients of meal consumed at night-time just before bed have strong impression on the sleep.¹ There is always a conflict in studies on whether to eat or not to eat before going to sleep. Earlier, several proposed that eating before bed increases the calorie intake that could lead to weight gain and increased risk for various cardio-metabolic disorders.

On the contrary, sleeping empty stomach is equally harmful for health and weight management. With the recent advances, it has been suggested that negative outcomes may not be persistent when the portion size is small, nutrient-dense, low energy or low calorie instead of large mixed-meals.²

This article looks into the risks and considerations of eating before going to bed at night, as well as the recommended intervals between meal and sleep.

Recommended intervals

“As a general thumb rule, the time interval between the last heavy meal and bedtime should be at least three hours.”

This helps in proper digestion of food in the stomach and prevents problems of heartburn and acid reflux.³

Factors influencing the meal and sleep

Age and activity: The composition, quantity and frequency of the meal just before bed varies significantly with age and activity of the individuals.

• In young active adults: The data on role of pre-sleep nutrition is limited. It may be advantageous for active young individuals to consume a small, nutrient-dense, high protein meal or drink before going to bed. The plausible hypothesis states that nutrient rich small meals before sleep helps in maintenance and improvement of body composition by providing overnight muscle protein synthesis and next morning resting metabolism in healthy physically active young individuals.²
• Time intervals: Several studies have also reported eating heavy or nutrient dense meals late i.e. after 8 pm and close to bed time is associated with higher caloric intakes. This behaviour can lead to metabolic dysfunctions because the response of insulin is lower to evening meals, thus causing increased blood glucose levels for longer periods.  This further leads to increased body mass index (BMI) and shorter sleep durations.
• Nutritive value: The composition of meal is equally important as that of timing in determining the quality of sleep. A number of macro and micro-nutrients are known to affect the onset and quality of sleep. Tryptophan, which is a precursor of serotonin in brain, is a sleep inducing agent known to influence the quality and quantity of sleep. Several macronutrients are known to influence sleep through tryptophan. A study compared the effects of high glycemic index (high-GI) and low glycemic index (low-GI) meals given 4 hours before bedtime on the sleep onset latency and sleep quality.  It was observed that both macronutrients and timings influence the quality of sleep. The high-GI meal significantly reduced the sleep onset latency as compared to the low –GI meals in healthy sleepers when consumed 4 hours before the bed-time.⁷ There are some nutritional factors with alter with the sleep mechanics and may cause decrease in the quantity and quality of sleep such as alcohol, caffeine and hyper-hydration.⁸

Risks and benefits of eating before bed

Benefits

Weight management: Earlier it was postulated that avoiding or limiting night-time meal would help in reducing the weight and improve overall health and body composition. With the arising interest in the night-time eating and its potential benefits,  studies have demonstrated a low calorie, low fat night-time snack instead of a typical high calorie high carbohydrate/fat food may actually be beneficial to overweight and obese individuals.² Waller et al. (2004) in their four week randomized controlled study observed fifty-eight obese overweight individuals who received 1 cup of ready to eat cereal 90 minutes after dinner as post dinner snack or pre-sleep meal. The findings from the study indicate a lower total daily calorie intake and modest weight loss (-0.84 ±1.61 kg) in subjects.⁹

Satisfied quality sleep: Quality sleep is very important for cognitive functioning, restoring energy, immunity and overall health. A disturbed sleep at night generally leads to stress, bad mood and slower performance the next day. Many studies have seen the effects of different diet compositions as pre – sleep meal and observed its effects on the quantity and quality of sleep. Kinsley et al. 2014 investigated the effect of different macronutrients i.e. carbohydrates v/s protein consumed at night as pre bed time snack in overweight and obese women. The single nutrient beverages having 140-150 kcals and supplemented 2 hours post dinner and 30 minutes before sleep revealed greater subjective satiety, quality sleep and less desire to eat. However, between carbohydrate and protein meal, food rich in protein showed better results.¹⁰

Glycogen disorders (GSDs) and Type 1 Diabetes (T1DM): GSDs are a group of genetic disorders resulting from defective enzyme activity required for glycogen synthesis or degradation. Type 1 GSD is characterized by deficiency of glucose-6-phosphatase liver enzyme required for the formation of glucose and maintenance of blood glucose levels. Similarly, T1DM is characterized by pancreatic beta cell dysfunction leading to defective insulin production as a result these individuals have to rely on artificial insulin in order to maintain blood glucose levels. Both Type 1 GSD and T1DM patients are highly susceptible to nocturnal hypoglycaemia and pre-sleep snack provides a good source of glucose throughout night.² Wolfsdorf JI et al. 1997 compared the effects of providing uncooked cornstarch orally as a bedtime or mid-night snack in Type 1 GSD patients and results demonstrated maintenance of blood glucose levels for 7 and 9 hours with single and divided doses.¹¹ Kalergis et al. 2003 studied the effects of standard bed time snack, cornstarch snack, protein rich snack and no snack on nocturnal hypoglycaemia in T1DM patient with intensive insulin management. They observed both standard and protein rich snacks prevented the nocturnal hypoglycaemia while no snack treatment had maximum number of hypoglycaemic episodes.¹²

Type II Diabetes Mellitus: In the patients with Type II Diabetes Mellitus, the morning hours are presented with a problem known as “Dawn Phenomenon”. It is described as the early morning hyperglycemia due to elevated fasting glucose driven by liver insulin resistance leading to excessive hepatic glucose production (HGP). Diet is considered as a very important factor in the management and treatment of Type II Diabetes Mellitus. In recent years, one dietary approach has gained a lot of attention that is the implementation of a bedtime snack in order to reduce the next morning fasting glucose. A low carbohydrate or protein snack before bedtime led to an increase in liver sensitivity that decreases the HGP and resultant fasting glucose levels in the morning.¹³

Risks

Formation of unhealthy habits/night eating or drinking syndrome: Over the years, it has been observed that the most critical period to refrain night eating for over 58% is between 10pm to 1am and among others i.e. 18% is between 1am to 4am. Night time eating habits generally turn into binge eating and lead to formation of unhealthy habits, weight gain, obesity and low BMI. With the course of time these unhealthy habits turn into night eating or drinking syndrome.¹⁴

Weight gain: Several studies have reported night time eating habits or late night meals as the reason for obesity. Consumption of high calorie foods at night before bed is generally associated with increased risk of metabolic diseases and weight gain.¹⁵

Metabolic disorders: Eating just before bed can worsen the symptoms of heartburn and acid reflux specially in patients with gastroesophageal reflux disease. Most of the studies advise light or low caloric meals at night and a time interval of atleast 3 hours before going to bed. Studies have also reported the benefits of walk, not lying immediately after meals and avoiding spicy foods at night time to reduce the worsening of the symptoms of metabolic disorders.^{3, 16}

Breakfast anorexia: Late night eatings or consuming extra calories at night are associated with several side effects. Breakfast anorexia or skipping breakfast is one of the common side effects observed in adults and kids. Nocturnal life and irregular meal times are mostly associated with hormones such as leptin, insulin and glucocorticoids. Late night meals can therefore affect the cardiometabolic and endocrine functions during the sleep and the following morning.^17,18

Conclusion

Quality sleep and healthy nutrition form the firm foundation for the health and well-being of humans. It is very important to understand the relation of nutritive intake with the quantity and quality of sleep. Several studies suggested to avoid or limit the last meal or the bed time snack to maintain weight, health and body composition. On the contrary, recent studies summarized the beneficial effects of a bedtime snack or meal. To conclude, it is really more about what you eat rather when to eat. It is not ideal to have a high caloric large meal just before bed. However, eating small clean, nutrient dense, healthy, single macronutrient foods might actually help with maintaining the metabolic balance and better quality of sleep.

References:

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