Sleep: Importance in controlling of weight

Sleep is very important towards the management and prevention of weight gain. Being able to sleep for the recommended 8 hours soon after the sunsets is vital towards being able to control your weight. This article is written for those who have read my article on "Chronobiology" and intend on maintaining only their metabolic circadian rhythm. In this article, I will explain the importance of maintaining a regular sleep/wake schedule and how it can prevent weight gain.

Studies have shown that the food seeking behavior and sleep/wakefulness are coordinated. Other studies have gone on to show that feelings of hunger are paired with vigilance during the daytime and feelings of satiety are paired with sleep during the dark. This explains why we tend to get very alert and unsettled when we are hungry and very sleepy and lethargic when we finish a large meal. Thus irregular and improper sleep patterns can implicate an irregular metabolism. If you are interested in learning more about the importance of sleep on managing weight click to read more.

Understand this:
Leptin is secreted primarily from our adipose (fat) tissue into our blood where it works on the hypothalamus in the brain to reduce food consumption and increase energy expenditure. Leptin is a feedback mechanism of the body to indicate there is a surplus of energy in the body.

Ghrelin is secreted by the stomach and pancreas to stimulate hunger. It is found in highest amounts before a meal and lowest amounts after a meal.

Know this:
Sleep-wake cycles are intertwined with metabolism (affecting satiety and hunger). Scientists are finding increasing evidence that the neurophysiological (the way that nerves function) and metabolic mechanisms (via hormones) for controlling food-seeking behaviors and sleep/wake cycles are overlapping with each other [1].

Numerous studies involving both animal models and humans have shown that sleep deprivation result in hyperphagia (overeating). Human studies have shown that short sleepers express reduced levels of leptin and increased levels of ghrelin [4]. Thus those deprived of sleep would have a larger appetite due to hormonal imbalances. To make things worse being in an environment where food is always readily available means that reduced sleep simply becomes an increased opportunity to eat [1].

Compound those factors in with:

• Reduced sleep and sleep instability have been related to impaired glucose and lipid metabolism [1], meaning foods eaten are not properly digested and most usually stored away directly as fat in adipose tissue.
• Reduced sleep causes fatigue and usually leads to reduced physical activities [1]; further reducing energy expenditure and contributing to weight gain.

You don`t need me to draw any conclusions for you, but I will anyways just for formality =).

Conclusion:
Reduced sleep leads to increased caloric intake and ultimately weight gain

Solution:
Maintain a regular sleep schedule and BE SURE TO SLEEP AT THE CORRECT TIMES! Do not stay up late enough to allow yourself to become hungry again.

Consequences of ignoring my advice
You decide not to listen and stay up late at night, most likely engaged in an activity that requires your concentration. Here is what happens next:

1. Your concentration will lead to the stimulation of your brain to incorrectly signal for hunger due to the overlapping of the circadian pacemakers and the cytokine system.
2. You ignore the hunger because you know if you eat at night you will be over consuming calories for the day and all the food eaten at night will be stored as fat. So you try to sleep off the hunger.
3. You can’t sleep. You become restless and uncomfortable due to the feeling of hungry. You will not be able to sleep until you eat.
4. You eat; leading to hyperphagia and overconsumption.

Exceptions:
There are times where we will need to stay up to either finish off our presentations for work tomorrow, or study for the final exam. So what do we do?

• Load up on low-density carbohydrates that are high in dietary fiber. Eat as much vegetables and fruits as you need to, to fill up your stomach and feel satisfied.

Reference:

1. M Garaulet, JM Ordova´s and JA Madrid: The chronobiology, etiology and pathophysiology of obesity. Int J Obes (Lond). 2010 Jun 22. [Epub ahead of print].
2. Vanitallie TB: Sleep and energy balance, interactive homeostatic systems. Metabolism. 2006. 55 (10 Suppl 2): S30–S35.
3. Garaulet M, Lee YC, Shen J, Parnell LD, Arnett DK, Tsai MY et al: Genetic variants in human CLOCK associate with total energy intake and cytokine sleep factors in overweight subjects (GOLDN population). Eur J Hum Genet. 2010. 18: 364–369.
4. Taheri S, Lin L, Austin D, Young T, Mignot E: Short sleep duration is associated with reduced leptin, elevated ghrelin, and increased body mass index. PLoS Med. 2004. 1: e62.

For your scientific interest: How is the sleep/wake cycle and food seeking behaviors related?

• The circadian pacemakers that control our sleep/wake cycles overlap with the cytokine systems (hormones) that control our metabolism and food intake [2]
• The two systems are connected by a molecule named “interleukin-6” [3]. The implications of this relationship are that individuals who suffer from sleep loss or sleep instability may most likely suffer from disrupted metabolic functions as well.

Thus sleep is very important for having optimal metabolic function. However the main reason sleep is so important for weight management is because our sleep-wake cycles are critical towards the resetting of our circadian rhythms each day. With a good circadian rhythm, our body is able to perform optimally and correctly when required. This is critical for the proper metabolism of food so there is minimal storage of energy as fat. For more information on how the circadian rhythm plays a role in weight gain please read the section: “Chronobiology: Utilizing the Circadian Rhythm to prevent obesity”.
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