With shorter days and falling temperatures, Mother Earth is sending out a blunt, tough-love message: Time to grow more hair, bulk up with fat and find a nice cave to ride out the coming starvation months of winter.
That worked fine for our neolithic ancestors, and maybe even our great-grandparents on the farm.
But as we move into the time of comfort-food stews and new-season TV shows that beckon us into winter cocooning, our bodies are heading into a particularly unhealthy time of year.
Your body is telling you to slow down, sleep more, huddle by the fire, tell stories and conserve your calories.
There are ways to winterize your body and minimize the impact of those prehistoric messages.
"Winter can have a pretty big impact on our physical health and emotional health," said Dr. Conrad Iber, a sleep expert with Fairview Health Systems in Minneapolis. "This is a good time for families to talk about what's coming and how to keep everybody healthier."
Here's what's coming at you, and what some experts say you can do about it:
More weight: Holidays, high-carb comfort foods and hibernation mean weight gain. And you're right: It is getting harder and harder to shed weight because each year you tend to lose half a pound of muscle mass and add a pound of fat.
"It's time to pay more attention to winter squash and leafy greens," said outpatient dietitian Kelly Scheller of Fairview Health Systems. "I know those sweets are calling, but this is really a time to eat slower and eat smarter."
Genetics determines most of where the fat settles on your body. A small portion, called brown fat, helps keep you slim by burning calories and creating heat. But white fat, especially on or in your belly area, stores energy and offers insulation -- great if you're stuck on an ice floe, but likely to increase your risk of diabetes, heart disease and other ailments.
What to do: Drink lots of water, eat more whole grains and a rainbow of vegetables, eat within an hour of waking, control portions and stay physically active. Cool the bedroom at night to sleep better because people with five or fewer hours of sleep a night are 50 percent more likely to be obese than those getting seven to nine hours.
More grumpiness: Shorter days mean less sunlight, the doorway to SAD, a condition as bad as it sounds.
Feeling grumpy, edgy, depressed, sluggish, sleepy, hungry, distracted, maybe even suicidal?
Seasonal affective disorder can start around now, worsening as the winter deepens and daily sunlight shrinks to less than nine hours. It's worse for the half of adolescents who are already sleep-deprived (compared with 30 percent of adults), Iber said.
"Teenagers' internal clocks already keep them up an hour later than adults" -- exacerbated by homework, texting, early school hours, 6 a.m. hockey practice, computer games, parties, updating Facebook pages and night school activities, he said.
What to do: Most helpful will be sunlight or its electric equivalent on your face (the strongest receptors are in your eyes), exercise, socializing and plenty of fruits and vegetables rich in vitamin D. Manage your day so you get enough sleep -- key for mental and physical competence on tests or at work, playing sports or an instrument, and retaining a good mood. Antidepressant drugs may be needed for deeper depression.
Tougher skin: Cold air and low humidity can dry and thicken your skin to help protect inside tissue, but can lead to chapped or cracked skin and lips.
What to do: Wear protective clothing and use moisturizer to avoid chapped hands and face. Consider shortening baths and showers and applying baby or mineral oil on skin afterward.
Colds and flu: This is prime time, mainly because we're all cooped up a lot more.
What to do: A good, balanced diet, exercise, fresh air and adequate sleep will help keep your resistance up. Get a flu shot.
Blood-flow change: Your body adapts to the cold by shifting more blood flow to interior organs and away from your hands, feet and face. That's good for survival but can be bad for feet and hands.
What to do: Regular exercise and a good diet will keep your circulation balanced so that you're less likely to have circulatory problems. Forgo hot coffee, which inhibits metabolism, and switch to hot tea, hot water or hot broth to warm up. Wear layers and cover your wrists, ankles and head when you're outside on cold days, to minimize heat loss.
Bottom line: Exercise, find ways to enhance sleep time, drink lots of water, eat right and get out into the sunshine.
"I tell people the key to staying healthy during the winter is keep the same pattern year-round -- stay active and pay attention to what you eat," said Melissa Dvorak, a physician's assistant at a Fairview Health Systems weight-loss clinic.
"Eat one rich cookie instead of 10. Make a list of 20 or so ways to exercise -- take a walk, do arm curls with soup cans, go shopping, walk at the mall, go up and down the stairs for 10 minutes, get a gym membership for the season, pick up an exercise DVD from the library," she suggested.
"Instead of a goal to lose 10 pounds by Thanksgiving, make your goal to be healthy and happy this winter," she suggested. "You can start today."