BLOG NUTRITION, FOOD, MOOD, HEALTH
January 18, 2018
You Are When You Eat
“You are what you eat.” Many of us have heard this motivational one-liner before as an attempt to help us eat healthier. Or, how about this one, “Your body is a temple, littering is strictly prohibited.” The issue with both of these is that, they don’t help me when my reward center hormones are surging when a warm cinnamon roll is sitting right in front of me when I haven’t eaten in eight hours. And if my body was really a temple, wouldn’t I want a temple dedicated to myself to be filled with my favorite things? I think we need a new “catchy, healthy eating slogan” to help ourselves out.
How about “you are WHEN you eat.” This is a new concept. So, let’s unpack this a bit. We, as humans run our day based on a strict schedule. We have alarm clocks telling us when to wake up, we have work deadlines, and our children have strict bedtimes. Why wouldn’t our meal times be just as important? This is what researchers across the country have been doing to understand the relationship between the timing of people’s meals, and their health.
This research is based off our bodies’ internal clock. This clock, called our suprachiasmatic nucleus, or circadian rhythm, is the cycle of sleep and wakefulness that the body goes through in a 24 hour period. This rhythm is associated with hormonal changes, bodily temperature and behavioral changes- all specifically curtailed to aid the body in maintaining optimal sleep and metabolic health.
What is common knowledge is that altering one’s circadian rhythm regarding sleep, like staying up too late, or working the night shift, can have detrimental health effects. But what researchers are finding is that circadian misalignment can happen with meal timing as well, putting our hunger hormones and metabolism off kilter as well.
To begin, studies have found that individuals resting energy expenditure, and dietary induced thermogenesis is increased in the morning. So people are burning more calories in the morning associated with the food they are eating, versus the rest of the day. Also, glucose tolerance is improved in the morning as well. So bodies are metabolically primed for a hearty breakfast meal.
In a 12 week experimental study, researchers placed 74 participants on a meal plan, one group placed the majority of their calories at breakfast, the other group at dinner (1). The breakfast group lost significantly more weight than the dinner group (1). This was regardless of meal content. Other studies have shown the same results, that the timing of the main (highest calorie) meal of the day is predictive of weight loss success.
The proposed mechanism of this is because diet induced thermogenesis (the calories needed to break down the food consumed) is 50% lower in the evening than the morning, and glucose tolerance is impaired in the evening as well. Coupled with poor sleep, and the increased hunger hormones ghrelin and leptin, this could potentially lead to weight gain and metabolic consequences.
In summary, researchers found that for study participants, the timing of the main meal during their day predicted their weight loss success. This was regardless of meal content. So follow your inner clock. Let this not only guide you to your bedtime and when you wake up, but your meal times as well. You may find that you are less hungry during the day, and eating less at night can help stabilize and control body weight. So, let your circadian rhythm, or your inner clock guide you to a healthier you!
1. Jakubowicz et al. Obesity 2013
2. Scheer, Frank AJL, and Laura Andromalos. “It's about time! Circadian system, meal timing and metabolism.” FNCE. FNCE, 22 Oct. 2017, Chicago, McCormick West.