Do you wake up about the same time every day sans alarm clock? Does your tummy start grumbling a few minutes past your regular lunch hour? That’s your ingrained body clock, and researchers now know that circadian rhythms — a 24-hour cycle that maintains your body’s schedule — play an important role in sleep, mood and weight gain.
Circadian rhythms are indelibly linked to weight because they affect body temperature, blood pressure, heart rate and hormones. Research conducted at Oregon Health and Science University suggests that during the “wake phase,” you metabolize food faster to provide the body with energy in the form of calories. In the “sleep phase,” your digestive tract slows down, body temperature drops and mental alertness decreases.
The Body Clock Guidelines
Make the most of your own circadian rhythms by following our body clock guidelines to lose weight, boost stamina and get fitter faster.
Your biological ticktock starts the moment you wake up and is affected by how long you’ve slept. According to the National Institutes of Health, circadian rhythms are produced by natural factors within the body, but they’re also affected by signals from the environment. Light is the main cue, which turns on or off genes that control sleep-wake cycles, hormone release and other body functions.
What to do: Buy blackout curtains, turn your phone off and catch up on at least eight hours of sleep per night.
Many studies suggest that sleep loss increases hunger and slows metabolism. Sleep loss has, in fact, been shown to affect the secretion of cortisol, a hormone that regulates appetite. As a result, if you lose sleep or wake prematurely, you may continue to feel hungry all day despite food intake.
What to do: Each morning, create a healthy wake-up regimen, such as a few minutes of stretching in the shower or in-bed meditation before bolting out and rushing through a harried morning routine.
Are you a morning exerciser? Eating 100 to 200 grams of carbohydrates within two hours of high-intensity exercise (either before or after) is essential to building energy stores for training. Waiting longer than two hours results in 50 percent less glycogen stored in the muscle and a less effective recovery. It may also lead to injury.
What to do: Lace up your walking or running shoes and blast about 300 calories in 30 minutes. If you did not eat a healthy breakfast before exercise, replenish carbohydrates afterward with a yogurt smoothie or a glass of OJ and several wheat crackers until you can hit the breakfast table or coffee shop.
Stressed about an early-morning meeting and tempted to nosh jelly donuts on your way to work? How about a little exercise instead? “Try releasing toxins first thing in the morning to stabilize your weight loss attempts,” said registered dietician Joan Clark, co-author of “The Complete Idiot’s Guide to the Glycemic Index .” “We carry stress in our muscles and getting out the kinks early in the day may relieve tension headaches and backaches.”
What to do: Lie in bed or on the floor and bring knees into your chest to stretch the lower back, then rock side to side slowly with eyes closed. Progress to 10 minutes of your favorite stretches.
The early bird who gets the worm also has the longest amount of time in which to blitz off those breakfast calories! The moment food enters your stomach, energy from digestion is allocated to deal with it. Eat lean sources of protein to prevent energy spikes throughout the day.
What to do: Grab a breakfast of lean protein and healthy carbs, such as an egg white omelet with a cup of veggies and a little cheese, or even a whole-wheat English muffin with fruit and a dab of cream cheese.
Prior to a lunchtime sandwich drink two 8-ounce cups of natural green tea (no sugar added). A study in the American Journal of Clinical Nutrition found that green tea extract, taken over a 24-hour period, increases metabolic rate by up to four percent. These effects are probably due to the high concentrations of catechin polyphenols, which boost fat oxidation.
What to do: Brew natural green tea leaves and keep a chilled batch in your travel mug, in the car, or on top your desk or dresser.
Drink two or three 8-ounce glasses of water if you have not already done so! Water helps maintain healthy body weight by suppressing appetite, reducing the body’s level of sodium and maintaining muscle tone. “It’s also necessary for proper kidney function, but it’s so easy to take water for granted,” said Dr. Donald Hensrud, co-author of “The Mayo Clinic Diet.” “Water cushions joints, carries waste away and protects your organs and tissues, too.”
What to do: For the body to metabolize properly, you should drink half your body weight in ounces per day, said Hensrud. If you weigh 130 pounds, for example, drink a minimum of 65 ounces of water, about eight 8-ounce cups.
Plan meals wisely: Lunch should contain protein, healthy fats, complex carbohydrates and non-starchy veggies to sustain stamina and curb cravings later. Make sure lunch is packed with fiber, too. “The high-fiber content of vegetables, fruit and whole grains bulk up your diet so you feel satiated longer,” said Hensrud. You require 25 to 35 grams a day!
What to do: To bypass bloating, feel alert and optimize digestion, incorporate oatmeal and apples into breakfast; whole-wheat bread and vegetables into lunch; and beans, legumes and greens into dinner.
Have a pickle for a snack! That’s right: Acidic foods significantly lower the glycemic index of a midday meal by one-third. What does that mean to dieters? “The slower your carbohydrates break down, the lower their glycemic index and the healthier your food intake,” said dietitian Clark. “Acidic foods slow the emptying of your stomach, which is a boon to any weight loss plan.”
What to do: Nibble acidic foods such as pickles, tangy salsa, marinated veggies or sourdough bread for lunch or snacks. Other acidic foods include horseradish, pickled beets, lemon juice and pickled herring.
Watch water intake midday: You may have to increase daily consumption during intense exercise as well as in hotter temperatures. (Psst: Medications require an increase of water intake, too, so check with your doctor.)
What to do: A good way to make sure you drink enough is to carry a stainless steel bottle of water with you at all times. Add sliced citrus to make it tastier.
This is your lowest energy point, when body temperature drops and cravings creep up. Sleep loss may interfere with the body’s ability to metabolize carbohydrates, which leads to high levels of blood sugar. Excess blood sugar promotes overproduction of insulin, which can lead to body fat storage and insulin resistance, critical to the development of diabetes.
What to do: Your body truly craves sleep now, according to your body clock: Try a short 20-minute power nap to rejuvenate. If that’s impossible, head outdoors in the sunshine to boost stamina and reset your body clock. If cravings strike, try chewing sugar-free gum or a fiber-filled apple.
Physical co-ordination, stamina and metabolic rate peak! Perfect time to slate a game of doubles tennis or schedule an early-evening kickboxing class.
What to do: Thirty minutes pre-workout, nibble a handful of raw almonds and drink a cup of green tea or even a small, low-fat mocha latte to fuel up. Natural appetite suppressants, like the caffeine in green tea or iced coffee, rebalance your brain and curb cravings.
In the early evening, core temperature is at its warmest, which makes your muscles and joints supple and helps you sidestep exercise strains and side stitches. Early-evening workouts that target your endurance muscles, such as core training, hardcore yoga stretching, and step-interval workouts, are best now.
What to do: Try a Power Pilates class or a Core Fusion DVD and you’ll feel pumped and primed for action all night long.
Hunger levels rise now, so drink another cup of green tea or sip soup before dinner to curb appetite. Scientists at the University of Chicago found that green tea caused rats to lose up to 21 percent of their body weight. Rats injected with green tea extract consumed 60 percent less food after seven days of daily injections, which may have something to do with the blood sugar-regulating effects of green tea.
What to do: If you are still craving solids but don’t want to ruin your appetite for dinner, try snacking on fresh fruit slices such as apple, watermelon, peach or orange, since these fruits have high water and fiber content.
High-cortisol hormone production brought on by, say, a horrid commute or a brawl with your boyfriend, can set off an unhealthy chain reaction that puts your body into evening crisis mode. Rebalancing brain chemistry with a balanced meal and a five-minute meditation sends out signals of well-being to combat these fight-or-flight hormones. More reasons to make dinner a simple, slow and contented affair.
What to do: Eat a meal high in omega-3 fish oils to help you drop inches and soothe stress. Studies at the University of South Australia found that eating omega-3 fish oil combined with moderate aerobic exercise jump-starts weight loss. Stir-fry a salmon filet (use peanut oil or other omega fatty acids) with two cups of cruciferous veggies and watch the pounds (and anxiety!) melt away.
Sip a cup of warm milk since the carbohydrate and insulin released make it easier for tryptophan to be absorbed into the brain, making you sleepy. Being fully hydrated regulates the body’s temperature and helps muscles contract, which, in turn, leads to a more productive workout tomorrow, not to mention a more restful night’s sleep.
What to do: Wind down gradually during evening hours with great conversation and good company. Alternate: If water or milk won’t cut it, sip a glass of antioxidant-rich red wine in the evening as a lower-calorie option to fattening bedtime snacks.
Can you padlock your fridge? Avoid eating additional calories in the evening, since your body gears up to extract all the nutrients you took in during the day. Eating food late at night and going to sleep forces the body to expend energy on digestion during sleep time, which is neither effective for dieting nor for snoozing.
What to do: Brush and floss your teeth so you’re not tempted to nosh.
Sustained high cortisol levels (and production of other stress hormones) can lead to intense cravings and binge eating at night, so it’s important to adopt a calming bedtime ritual, such as taking a bath, playing with your kids or reading a book for several minutes before lying down.
What to do: Jot personal notes into a food and exercise diary before you hit the sack, including workout times, calorie counts and other mind-body notes. Identify your weak willpower moments, as well as your most satisfying meals, and you’ll set yourself up for success tomorrow.
You should be sleeping now, not stressing! Studies show that decreased amounts of deep REM sleep can lead to increased food intake. Abnormal circadian rhythms have also been the cause for the symptoms of bipolar disorder and depressions.
What to do
Understand what makes your biological clock tick from day to day, which will lead to healthy weight loss, regular workouts and a happier life.