Insufficient Sleep Diet — From Cortisol to Muscle Loss, Sleep Duration
Table of Contents
Sleep Deprivation Diet — From Cortisol to Muscle Loss and Sleep Duration
Have you ever reduced your sleep in an attempt to lose weight? In my clinic, I very often hear the question, "If I don't sleep at night, wouldn't I use more calories?" However, the so-called sleep deprivation diet, which attempts to lose weight by reducing sleep, is unfortunately an inefficient method for both weight loss and health. Today, I will explain why this is the case and how you should change your direction, as if I were summarizing it for you in the clinic.
Reducing sleep makes your body more prone to gaining weight
When you lack sleep, your body perceives it as stress. At this time, the secretion of a stress hormone called cortisol increases, which raises blood sugar by increasing insulin resistance. When insulin resistance increases, fat storage increases even if you eat the same amount, making weight loss that much more difficult.
Hormones that regulate appetite also fluctuate. Various studies have reported that sleep deprivation decreases leptin, which signals satiety, and increases ghrelin, which stimulates appetite. This means that craving late-night snacks and overeating when staying awake late is not simply a matter of willpower, but is linked to hormonal changes.
Fatigue is added to this. Common causes of fatigue are sleep deprivation, stress, and overwork. When the body is exhausted, natural movement during the day decreases, and total daily energy expenditure drops accordingly. In effect, you end up spending less energy than the time you saved by sleeping less. For reference, most adults need 7~9 hours of sleep per day, and it is known that lacking this increases the risk of blood sugar issues and metabolic diseases.
Even if weight drops similarly, what is lost is different
The most painful part is "what is being lost." One set of data compared a group whose sleep was restricted to 5.5 hours a day with a group that slept sufficiently for 8.5 hours under the same diet conditions. The results showed that the 5.5-hour group lost 0.6kg of fat and as much as 2.4kg of lean mass, such as muscle. In contrast, the 8.5-hour group lost 1.4kg of fat and 1.0kg of lean mass.
If you look at the numbers side by side, the answer is clear. If you reduce sleep, the scale may go down similarly, but the fat you actually need to lose is lost less, and the muscle you need to protect is lost more. When muscle decreases, the basal metabolic rate drops, increasing the risk of the yo-yo effect and metabolic decline. Your body changes from one that loses weight to one that gains weight easily.
Control of food intake is also hindered. In a study of 43 people, calorie intake on the day following sleep deprivation increased by an average of 200~500kcal. Eating just 300kcal more a day can accumulate approximately 9,000kcal in a month, which corresponds to about 1.2kg of body fat (this is a calculation based on calorie conversion). Observational studies have repeatedly reported that people with a sleep duration of 6 hours or less have a higher body mass index and an increased risk of obesity.
In the clinic of Korean medicine, sleep is seen as the root of metabolism
In Korean medicine, sleeping well has long been regarded as the foundation for recovering the body. The night is a time to gather the energy used during the day and restore the body's balance; if this time is disrupted, it is believed that digestion and metabolic rhythms are also shaken. In fact, among those I see in the clinic, those who sleep lightly and wake up frequently often complain that swelling does not subside easily and appetite control is difficult.
That is why, when conducting diet consultations, I always bring up sleep as much as diet and exercise. If you only reduce the amount you eat while leaving the root—sleep—untouched, it is easy to experience a losing weight loss where muscle is lost first, as seen above. Since the reasons for sleep disturbance differ for each person, I recommend starting by observing your own body's rhythm.
Things you can change starting tonight
You don't have to think of it as something grand. I'll point out the small things.
- Use sleep time as a diet tool: Instead of reducing sleep, try to secure 7~9 hours a day. Sufficient sleep itself is a powerful weight loss tool that protects fat and saves muscle.
- Keep naps short: When sleepy during the day, keep it within about 20 minutes. If it's too long, it interferes with night sleep.
- Slow down the rate of weight loss: A safe goal is losing about 0.5kg per week. Rather than starving urgently, continuing to eat small portions consistently results in less loss and less breakdown.
- Understand late-night snack signals: The surge in appetite at night is largely due to hormonal changes. Instead of blaming yourself, try changing your environment to go to sleep earlier.
For those with type 2 diabetes, please remember that adequate sleep is as important for blood sugar management as diet and exercise.
I fully understand the desire to lose weight by reducing sleep. However, please remember that, as summarized today, that method carries a great loss by giving up muscle before fat. Sleeping well is half of the diet. If you struggle alone and sleep, appetite, and metabolic rhythms are not easily managed, I recommend examining your constitution and life rhythm together with the Baekrok-Gambi-jung tablet program. At your next visit, please feel free to tell me how your sleep has been lately.
Reference Materials
- PubMed — Body-weight-specific and shared metabolomic responses to acute sleep loss in you
- PubMed — Adolescent sleep restriction, macronutrient consumption, and self-reported hunge
- PubMed — Mechanisms Linking Sleep-Disordered Breathing and Cardiometabolic Disease Risk.
- Sleep health guide to induce deep sleep for World Sleep Day
- Must move more if lacking sleep
- Blood sugar also spikes if you can't sleep... as important as exercise and supplements
- How to improve sleep quality by age group for those in their 20s to 50s
