Why When You Eat Might Matter More Than What You Eat
When it comes to health and wellness, it is all about small sustainable changes. Taking the stairs instead of the elevator, adding a handful of spinach to your morning smoothie, or meal-prepping for the week ahead. These small changes can add up to big results. And now we have one more easy tweak that might lead to a major payoff: meal timing. According to a new study, shifting when you eat might actually matter more than what you eat when it comes to body composition and health benefits.
In the study, published in the Journal of Nutritional Science, one group of participants was asked to delay their breakfast by 90 minutes and consume dinner 90 minutes earlier than usual, thereby extending their nightly "fasting window," the time between dinner and breakfast, by 180 minutes. Participants were not told to follow any specific dietary guidelines but rather could eat freely as long as it was within the eating window. The control group was not given any restrictions on diet or meal timing. After 10 weeks, the time-restricted feeding participants had lost, on average, more than twice as much body fat as the control group. So without following a strict diet or even focusing on changing what they ate, the time-restricted group lost more body fat simply by changing when they ate.
This may be because participants who modified their meal times were found to eat less food overall than the control group. In fact, 57 percent reported a reduced appetite, decreased eating opportunities, and a cutback in nighttime snacking. Meaning: Restricting when they ate prompted them to unintentionally restrict how much they ate without feeling deprived.
Although this study was small, it provides important insights into how time-restricted feeding and other forms of intermittent fasting may affect dietary intake, body composition, and overall health. Researchers are eager to continue exploring this connection and expand to larger trials to understand the full range of benefits.
The benefits of intermittent fasting go way beyond weight loss.
The type of diet used in this study is a form of intermittent fasting, the practice of extending the time period between meals, typically dinner and breakfast. Intermittent fasting has been gaining a lot of traction recently—in fact, we named it one of the 2018 Wellness Trends to Watch. This isn't just a new weight loss fad, though, and intermittent fasting goes way beyond weight loss. It has been credited with everything from clearing brain fog and healing the gut to decreasing inflammation and fighting cancer.
Integrative neurologist, Ilene Ruhoy, M.D., calls fasting "one of my favorite multitasking tools to help you fight inflammation, improve digestion, and boost your longevity," explaining that, "just as you and I need sleep to reset and revitalize, so does our digestive tract and organs." Basically, when you fast, your body gets a break from digestion and can focus on other important mechanisms, like clearing away damaged cells that may be prone to diseases. This process, called autophagy, is at the heart of how fasting boosts the immune system, fights chronic disease, and extends longevity.
In addition, fasting allows for increased blood flow to the brain, improving cognitive function. In fact, one study found that fasting acts as a decluttering mechanism in the brain. The study found that fasting may "slow down" some of the overactive synaptic activity associated with Alzheimer's, Parkinson's, and other degenerative diseases.
Of course, fasting isn't for everyone.
Although fasting has a long list of benefits, there are some people who should avoid fasting. Experts warn that women who are pregnant or breastfeeding should not try fasting. Also, anyone with a history of disordered eating may find this plan triggering and should pass on fasting. In addition, mbg Collective member JJ Virgin recommends that anyone with an adrenal issue, blood sugar imbalance, or diabetes should proceed with caution. As with any new health regimen, always talk to your doctor before starting out.
Also, it is important to remember that fasting is not an excuse to binge on unhealthy food during the "feeding window." Eating a healthy, balanced diet will keep you satiated through the fasting periods and also support overall health. Whether you choose to intermittent fast or not, you should focus on eating a variety of fruits and vegetables, whole grains, and healthy proteins and fats.
Darcy McDonough, M.S., is the Senior Manager, SEO & Content Strategy at mindbodygreen. She holds a master’s degree in nutrition interventions, communication, and behavior change from Tufts Friedman School of Nutrition Science and Policy. She has previously worked in nutrition communications for Joy Bauer, the nutrition and health expert for NBC’s TODAY Show.
McDonough has developed & lead nutrition education programming in schools. She’s covered a wide range of topics as a health & nutrition reporter from the rise in the use of psychedelics for depression to the frustrating trend in shorter doctors' appointments and the connection between diet and disease.