What is the link?

Unsatisfactory sleep consists of 4 to 6 cycles on average with a duration of 90 to 110 minutes. Of course, the number and duration of courses varies depending on several variables (age, gender, pace of life, physical activity, diseases, etc.).

Sleep is divided into several stages:

1. The first stage is the sleep stageIt represents approximately 5% of the total duration of the night. It is an interval between wakefulness and sleep, and it is a period of drowsiness with the appearance of numbness in the muscles.
2. The second stage is also called light slow-wave sleep Corresponds to 50% of the night. The brain is still receptive to external stimuli. Breathing and heart rate slow. The subject is still easy to wake up.
3. Stages 3 and 4 correspond to deep slow wave sleep. It is important that these stages represent at least 25% of the night. The brain is less attentive to external stimuli. Breathing and heart rate are slow. Muscle atony is also noted. It becomes more difficult for the subject to wake up.
4. The fifth or most common stage is called paradoxical sleep Corresponds to the dream stage. This stage represents 20% of the night. Irregular breathing and heartbeat. Rapid eyelid movements (REM) are characteristic of this stage.

The structure of the cycles evolves throughout the night. The first half of sleep is especially rich in deep slow-wave sleep (stage 3). Conversely, the second part of the night will be more represented by alternating slow-wave sleep and paradoxical sleep.

Sleep is vital, and its role is both restorative (physical, intellectual and psychological) and regulatory (circadian rhythm and metabolism).

certainty : according to DNS Association,⁽¹⁾ 77% of French people do not realize that lack of sleep leads to weight gain. There is a general lack of understanding of the relationship between diet and sleep disorders.

What are the links between diet and sleep disorders?

As described above, sleep disturbances, diet, and excess weight “form a vicious cycle.” The causes and consequences are multifactorial.

Sleep disturbances can be explained by various reasons, including:

• the pressure
• Consumption of stimulants
• Irregular pace of life
• Excessive use of screens
• Certain diseases, including obstructive sleep apnea syndrome
• And food

The most common consequences associated with sleep disorders

• Chronic fatigue
• Daytime sleepiness
• Mood disorders or even depression
• Vigilance disorders: increased risk of an accident
• Increased risks of certain diseases, particularly cardiovascular diseases, type 2 diabetes, and cancers but alsoobesity.

What do scientists say?

Some studies confirm the existence of these links and the importance of not neglecting diet or sleep.

2015 survey National Institute of Sleep and Wakefulness The INSV shows that among short sleepers (sleeping less than 6 hours), the risk of obesity increases by 34% in women and 50% in men (particularly due to nighttime snacking).

This study also shows that people with obesity have an increased risk of insomnia (+43% in women) but also have an increased risk of obstructive sleep apnea syndrome (×16 women/×11 men).

What are the consequences of lack of sleep on our metabolism?

Lack of sleep affects two types of factors:

• Hormonal factors By increasing the duration of secretion Ghrelin Which will increase appetite. Ghrelin is an appetite hormone, which is normally secreted during the waking phase. In parallel, a decrease in the duration of secretion Leptin It will lead to a decrease in satiety. Leptin is a satiety hormone, which is normally made during sleep.
• Behavioral factors By increasing the time awake and therefore the time available for eating but also increasing fatigue, suppression of physical activity and the factor initiating snacking.

What scientists say:

A study conducted by Dr. St. Onge in 2016⁽²⁾ It demonstrates the effect of products consumed during the day on the quality of sleep the following night.

The results show the following facts:

• A high-fiber dinner increases the speed of falling asleep as well as the duration of deep, slow-wave sleep (stage 3).
• Dinner rich in saturated fatty acids reduces the duration of deep sleep.
• A dinner high in sugar/refined carbohydrates increases the frequency of microarousal.

Nutritional recommendations

• Limit caffeine intake (Tea, coffee, soft drinks containing cola, energy drinks) during the day, especially after 4 pm, in order to reduce sleep instability (delaying falling asleep and waking up at night) through its psychostimulant effect.
• Limit alcohol consumption in the evening It certainly favors sleep through its muscle relaxant effect but also through sleep instability: “rebound insomnia”.
• Dinner should not be eaten too late To avoid sleep delay (by increasing body temperature) as well as sleep fragmentation caused by difficulty digesting.

Here's the perfect dinner :

General recommendations

• Limit tobacco consumption in the evening To reduce sleep instability.
• Avoid consuming sleeping pills Promoting “rebound insomnia.”
• Doing physical activity during the day.
• Respect a regular bedtime schedule Enhance sleep/wake synchronization.
• Try creating a “bedtime ritual”: Relaxing reading, herbal tea, breathing exercises, relaxation…the brain interprets it as sleep signals.
• Improve room ambiance: Temperature at 18°C, quiet and dark.
• Limit screen use in the evening (cell phones, tablets, etc.) in order to reduce the emission of blue light, which leads to delaying the secretion of melatonin.
• Go to bed at the first sign of sleep : Yawning, itchy eyes.

It is undeniable that there is a relationship between sleep disorders and diet. Therefore, all factors must be taken into consideration when treating excess weight or a sleep disorder.

Obstructive sleep apnea syndrome is closely linked to excess weight. In this case, multidisciplinary care should be encouraged.

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