Heath Notes
Sleep More, Eat Less
If you sleep less than 7 hours a night, you’ll likely eat more. For every hour less you sleep, you raise your chance of being obese by 10%. That’s a lot. In a recent study, those who slept only 5 hours a night ate 200 more calories per day. At this rate, you would gain 20 pounds a year! Even in a short study, the sleep-deprived group gained an average of half a pound in two weeks.
A lot of hunger is controlled by hormones, and lack of sleep increases the hormone that makes you hungry and decreases the hormone that makes you feel full. Also, lack of sleep impairs your planning brain, giving your pleasure-seeking brain the steering wheel.
Sleep is vital to good health, and 7—9 hours of sleep is essential to maintaining a healthy weight.
Light Up Your Life
Our eyes need light for more than just seeing. They are linked to our brain chemistry. Without enough sunlight, our dopamine levels can become low (see dopamine article in this issue for more details). One side effect of low dopamine is that the shape of our eyeball changes, and we become nearsighted. Recently, nearsightedness has been skyrocketing in children. Almost half of the children in North America and nearly 3/4 of children in Asia are nearsighted. For a child, an extra 10 hours a week outdoors reduces the chances of being nearsighted by a third.
Spending too much time looking close-up at screens is bad for your vision. Our eyes need to look off into the distance to maintain good vision. Our parents told us not to sit too close to the TV. They weren’t wrong. We need to get outdoors, see the horizon, and get sunlight. No matter your age, every day, spend time outdoors scanning the horizon. It’s good for your eyes and your soul.
Sunshine Regulates
Sunlight is for more than just seeing. Sunlight also regulates our hormones, including our sleep hormones. Our eyes have sunlight sensors that have nothing to do with vision. Our brain wants to know when the sun is shining---even if you’re blind. There are special proteins in our eyes that sense light but aren’t involved in seeing. We even have some of these in our skin. Your skin can sense light! Some animals, like octopuses, use these proteins to ‘see’ with their skin to camouflage it to match their surroundings. We can’t do that, but our skin can sense light.
Because light is vital for staying alert, you should avoid dark rooms during the day. If there are not enough windows in the room, turn on some lights. If you depend on artificial light, try to use light bulbs that give the entire light spectrum. These light bulbs are often called daylight bulbs. They seem bluer, but their light is more similar to sunlight.
Light tells the brain to be awake. It suppresses melatonin which makes you sleepy. To sleep well, you should start avoiding bright lights 3 hours before bed. In the 3 hours before bed, slowly darken the room more and more. Just before bed, you should have almost no light hitting your eyes. While sleeping, keep the room completely dark.
Work with your body’s light sensors to sleep better at night and be sharper during the day.
Walk 10 Minutes More
Walking is not vigorous exercise, but it can be moderate exercise. Strolling isn’t exercising, but it is fun. Make sure you’re walking fast enough to raise your heart rate. For a 65-year-old, moderate exercise is about 100 bpm, give or take 15 bpm. Your heart rate is in the proper range if you’re breathing hard but can still talk. Walking is good for the heart and your joints. Joints need movement to stay healthy. It’s also good for your back, as walking balances core muscles. It’s even good for your mind.
Take a 45-minute walk every day---more is even better. It’s a good idea to track your steps with a smartphone---just keep it in your pocket while walking. Fewer than 3,000 steps a day is unhealthy. Aim for more than 5,000 daily steps---10,000 is a good target. It takes about an hour and a half to walk 10,000 steps, but you can add walking to your errands and daily activities.
Time spent walking is worth it, according to a huge, long-term study. Every extra 1,000 steps a day lowers your risk of dying in the next few years by about 10%. 10,000 steps a day reduce your risk of dying in the next few years by 50%. Walking more than 15,000 steps a day has even more health benefits.
Adding an extra 1,000 steps takes about 10 minutes. Spend 10 more minutes walking to add to your days.