Effects of Sleep Deprivation on Weight Gain

Among my most painful memories from university is the feeling of panic that consumed me two weeks into my third year. Taking five heavy courses and three labs, I was academically drowning, barely keeping my head above water. 

To get into grad school, I needed good grades. As a last resort, I devised a plan:

I would cut my sleep in half, waking up each morning at 4:30 a.m. to study for several hours before class.

Three weeks of my new routine proved successful.

I capitalized on those peaceful early mornings and started catching up. As midterms came and went, it appeared I was salvaging my semester.

But something strange also happened:

My nutritional discipline went off the rails. I knew what to eat, but I couldn’t force myself to eat it. Black coffees were replaced by sugary lattes. Salads were replaced by poutines at the campus pub. 

I felt possessed by an inner demon intent on stealing my willpower and devouring calorie-dense foods.

Did sleep deprivation play a role in eroding my discipline?

The next semester, I took a molecular endocrinology course which answered my question. We began our unit on nutrition by examining two key hunger hormones:

Ghrelin and leptin

In 2000, a landmark paper showed that injecting ghrelin into rodents’ brains increases in their food intake. Leptin and Ghrelin work in concert to regulate our appetite.

When we need calories, we produce more ghrelin and less leptin, making us hungry. When we’ve had enough, we produce more leptin and less ghrelin, making us feel full. Ghrelin makes you hungry by enhancing the release of hormones that activate the “rest and digest” branch of the nervous system. 

Leptin is the yin to ghrelin’s yang. When released, leptin makes you feel full by modulating the same downstream hormones as ghrelin, but with precisely the opposite effect.

How does all this hormone mumbo-jumbo relate to my undergrad experience?

It turns out that sleep deprivation profoundly hijacks our hunger hormones.

In 2004, researchers in Chicago performed a randomized controlled trial examining how sleep deprivation impacts leptin levels. They discovered that leptin concentrations were 20% lower in participants restricted to six hours of sleep, rather than nine.

Using a similar protocol, they found that sleep deprivation triggered an equal but opposite 20% increase in ghrelin concentration. Increased hunger accompanied this hormonal shift.

I had the answer to my predicament during Undergrad.

Sleep-deprivation elicits hormonal chaos

When I slashed my sleep in half, leptin tanked, ghrelin soared, and I started making terrible food decisions.

Effective solutions to complex problems are often counterintuitive.

How should people improve their nutrition habits?

The obvious answer is that they should just eat better. But if it were really that easy, wouldn’t everyone do it?

Most of us know how to eat well. The issue is actually doing it. Why not make it easier on yourself, and attack the problem multiple angles?

Optimize your sleep, and you might just unknowingly optimize your nutrition.

Video: More on the effects of sleep deprivation on the brain and body.

References

Tschöp, M., Smiley, D. L., & Heiman, M. L. (2000). Ghrelin induces adiposity in rodents. Nature, 407(6806), 908.

Cowley, M. A., Smith, R. G., Diano, S., Tschöp, M., Pronchuk, N., Grove, K. L., … & Garcia-Segura, L. M. (2003). The distribution and mechanism of action of ghrelin in the CNS demonstrates a novel hypothalamic circuit regulating energy homeostasis. Neuron, 37(4), 649-661.

Kamegai, J., Tamura, H., Shimizu, T., Ishii, S., Sugihara, H., & Wakabayashi, I. (2001). Chronic central infusion of ghrelin increases hypothalamic neuropeptide Y and Agouti-related protein mRNA levels and body weight in rats. Diabetes, 50(11), 2438-2443.

Keim, N. L., Stern, J. S., & Havel, P. J. (1998). Relation between circulating leptin concentrations and appetite during a prolonged, moderate energy deficit in women. The American journal of clinical nutrition, 68(4), 794-801.

Kristensen, P., Judge, M. E., Thim, L., Ribel, U., Christjansen, K. N., Wulff, B. S., … & Larsen, P. J. (1998). Hypothalamic CART is a new anorectic peptide regulated by leptin. Nature, 393(6680), 72.

Spiegel, K., Leproult, R., L’Hermite-Balériaux, M., Copinschi, G., Penev, P. D., & Van Cauter, E. (2004). Leptin levels are dependent on sleep duration: relationships with sympathovagal balance, carbohydrate regulation, cortisol, and thyrotropin. The Journal of clinical endocrinology & metabolism, 89(11), 5762-5771.

Spiegel, K., Tasali, E., Penev, P., & Van Cauter, E. (2004). Brief communication: sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite. Annals of internal medicine, 141(11), 846-850.