The alarm clock rings. It’s pitch black outside. It’s so cold out there; so warm under the covers. You roll over and hit the “snooze” button. After the third “snooze” you reluctantly slip out of bed and into the shower, get dressed, eat a quick breakfast and rush out the door for work, driving in the dark. As midmorning rolls around, you can think of nothing but that gooey apple fritter you saw at the coffee stand in the lobby. Noon brings a trip across the street for lunch. Oooh…they have big soft hot pretzels and cream of tomato soup…you resist that, but decide on the whole grain grilled cheese sandwich. So warm and soft and delicious. By 2PM your eyes are droopy and you can barely concentrate on your work. A co-worker tells you he’s getting a Cinnamon Dolce Crème Frappuccino from downstairs and asks if you want one. That sounds like the only way you’re going to get through this day. Finally work is over, you drive home in the dark, and eschew your regular workout…you’re just too tired. Your planned dinner of steamed veggies and that salmon fillet in the freezer doesn’t seem very appetizing, so you order in a pizza, watch a little TV, and turn in early.
If some or all of these things sound all too familiar to you, you’re not alone or abnormal. You’re experiencing your body’s reaction to the winter, and specifically lack of light. Over the millennia of human existence, these behaviors probably evolved as a mechanism for our bodies to conserve energy, increase fat and prevent wintertime starvation. (1) As the days have less and less light, your brain makes less of an important neurotransmitter called serotonin. Serotonin indirectly or directly controls most brain functions, including mood and sleep cycles. Serotonin levels are highest in the brain when you are awake and active, and almost completely absent when you enter the deepest stage of sleep. During sleep, another neurotransmitter, called melatonin, rises sharply. Melatonin is made in the pineal gland, and is regulated by serotonin. Light increases the production of serotonin, while darkness increases the synthesis of melatonin. Thus, these two neurotransmitters maintain balance in the sleep cycle, determining how sleepy or how alert we feel.
As the days get shorter and darker and serotonin levels fall, most people crave carbohydrate-rich foods. Eating sugary or starchy foods boosts serotonin in the following way. First, the sugar or starch causes insulin to be secreted. The insulin, in turn, increases tryptophan in the brain. This is a major building block for serotonin. Unfortunately, the secretion of insulin drives down our blood sugar, making us even more hungry for sugary and starchy foods. In addition, the increased insulin causes more of the food we eat to be turned into fat. And the elevation in serotonin doesn’t last very long; so the cravings are almost constant.
Seasonal Affective Disorder (SAD) is a condition where the decrease in serotonin in response to low light is exaggerated. For people who suffer from SAD, symptoms appear during late fall or early winter and go away during the sunnier days of spring and summer. The symptoms of SAD include:
- Heavy, “leaden” feeling in the arms or legs
- Appetite changes, especially a craving for foods high in carbohydrates
- Weight gain
- Difficulty concentrating
If these things are happening to you, it’s important to see your doctor and get some specific treatment recommendations. Interestingly, people who have Seasonal Affective Disorder also have decreased leptin response, and therefore do not regulate their appetite normally in response to body fat. (2)
But even without SAD, a tendency to gain weight when the weather turns cold and dark is a well-known phenomenon. (3) In winter, a person’s weight creeps up on average by about 0.5kg. Also, in many individuals lipids in the blood change, with increasing triglycerides and LDL, and decreasing HDL. Hemoglobin A1c also increases. (4,5) And everything just seems to s-l-o-w d–o–w–n.
So, how do you keep your body from succumbing to the “winter doldrums”? Enter (TA-DAAA!) The Smarter Science of Slim! (6) SANE eating and smarter eccentric exercise is the very best way to keep your body in “summer mode”, stave off carbohydrate cravings, keep your energy level high, and keep your body burning fat and building muscle. Here are some specific recommendations:
- Eat SANEly, with macronutrient balance of lean complete proteins, non-starchy vegetables, and healthy fats. This will maximize manufacture of serotonin from tryptophan, and keep the carbohydrate cravings at bay. When you are full of lean protein and non-starchy vegetables, cravings go away. And healthy fats feed your “neurotransmitter factory”. Particularly, long-chain omega-3 fatty acids have been shown to help regulate the brain’s serotonin levels.
- Light up your life! Take advantage of the sun when it shines by going for a walk outside at midday if possible, and consider using full-spectrum work lights on cloudy days or when you can’t go out.
- Don’t forget Vitamin D. This is essential for healthy bones, but may also affect fat metabolism. If you live where there is very limited sunshine and you can’t get outside, you may want to consider a vitamin D supplement in the winter.
- Exercise! Smarter eccentric exercise as described in “The Smarter Science of Slim” will markedly increase your fat-burning hormones and your feeling of general well-being. It’s particularly important to keep up with your exercise program in the winter in order to continue burning fat, building muscle, and feeling good.
- Be active; have fun. Meditation and yoga, dancing, taking a walk, playing at a sport, listening to music, playing an instrument or singing in a choir can also increase serotonin levels. (7)
So, turn up the lights, turn on the music, eat SANEly, exercise ECCENTRICally, and create a little bit of SUMMER in your metabolism!
- Davis C, Levitan RD. Seasonality and seasonal affective disorder (SAD): an evolutionary viewpoint tied to energy conservation and reproductive cycles. J Affect Disord. 2005 Jul;87(1):3-10
- Cizza G, Romagni P, Lotsikas A, Lam G, Rosenthal NE, Chrousos GP. Plasma leptin in men and women with seasonal affective disorder and in healthy matched controls. Horm Metab Res. 2005 Jan;37(1):45-8
- Yanovski JA, Yanovski SZ, Sovik KN, Nguyen TT, O’Neil PM, Sebring NG. A prospective study of holiday weight gain. N Engl J Med. 2000 Mar 23;342(12):861-7
- Donahoo, William T, Dalan R. Jensen, Trudy Y. Shepard and Robert H. Eckel. Seasonal Variation in Lipoprotein Lipase and Plasma Lipids in Physically Active, Normal Weight Humans. The Journal of Clinical Endocrinology & Metabolism September 1, 2000 vol. 85 no. 9 3065-3068
- Bardini G, Dicembrini I, Rotella CM, Giannini S. Lipids seasonal variability in type 2 diabetes. Metabolism. 2012 Dec;61(12):1674-7
- Bailor, Jonathan. The Smarter Science of Slim: What the Actual Experts Have Proven about Fat Loss. Aavia Publishing, 2012
- Young, Simon N. How to increase serotonin in the human brain without drugs J Psychiatry Neurosci. 2007 November; 32(6): 394–399.