Timing.
A growing number of studies show that while the types of foods you eat affect how much you weigh and how much body fat you carry around, the times when you eat your food also matter. It’s a factor that most people overlook.
Studies now show that a big reason so many of us carry around too many pounds is that we’re eating at the wrong times.
Our technology-dominated world means we’re bathing ourselves in light from smartphones, video screens and other light sources long after the sun goes down. That’s wreaked havoc on the body’s circadian rhythms – our internal physiological clocks.
Your 24 hour circadian rhythm determines much of what happens in your internal organs – including the release of hormones, changes in body temperature, when you feel sleepy and shifts in your blood pressure.
In the past, before we had electric lights, our circadian rhythms were tightly connected to the rising and setting of the sun and the timing of our meals.
With these bodily cycles in mind, researchers at Brigham and Women’s Hospital in Boston investigated the relationship among meal and snack times, the body’s circadian rhythm, and weight gain.
Eating Late Puts on the Pounds
They discovered that if you eat near bedtime, a time when your internal rhythm is getting you ready for sleep, the hormone your body releases at that time – melatonin, which is designed to make you feel sleepy – interacts with the digestive system in a way that increases the manufacture of body fat from the energy in your food.1 In their 30-day study, the researchers focused on data from more than 100 people and noted their ups and downs in melatonin, when they went to bed, the timing of their calorie consumption, their weight and their percentage of body fat.They found that people who ate relatively large meals and snacks right before bed, when their melatonin levels were peaking, had the highest body fat percentages. And they believe that it results from the interaction between melatonin and other hormones with the body’s processing of food that increases the storage of fat and leads to weight gain.
Other studies confirm the conclusions of the Boston researchers.
For instance, a lab test at the University of Texas shows that if you cut the amount of food you eat, but eat your meals late at night around bedtime, you won’t lose as much weight as you would if you ate your food earlier in the day.2 This study was performed on animals, but the researchers say the results apply to people.
“Translated into human behavior, these studies suggest that dieting will only be effective if calories are consumed during the daytime when we are awake and active,” says researcher Professor Joseph Takahashi, Ph.D. “They further suggest that eating at the wrong time at night will not lead to weight loss even when dieting.”
Increased Risk of Diabetes and Heart Disease
Along with making you weigh more, researchers at Vanderbilt University have found that eating at the wrong time disrupts the body’s attempts at maintaining its internal clock and can increase your risk for diabetes and heart disease.A key reason late-night eating increases these health risks is the fact that your melatonin release at night lowers your insulin sensitivity. The Vanderbilt scientists conclude that by disrupting your circadian rhythm when you eat at what the body considers to be the wrong time, you also increase your risk for developing insulin resistance – leading to diabetes, obesity and heart problems.3 Added to those risks, researchers at Rush University Medical Center in Chicago have found that these disruptions change the bacteria that live in your intestines in a way that makes you more vulnerable to inflammation. And that can lead to the whole host of diseases that inflammation can bring on – including cancer.4 As you can see there are many reasons to avoid late-night munching. Keeping your weight down is only one of them. So if you forgo eating after dinner and postpone your next food until the morning you can both lose weight and improve your health. That sounds like a great combo to me.
