If your phone needs a software upgrade, you would likely run the installations when it’s fully charged. Otherwise, your phone and its software would take longer to sync. A new study finds human energy systems operate in a similar fashion: Our metabolisms likely function best in the morning when our bodies are fresh and fully charged.
The research, based on a seven-year dietary analysis of 50,000 adults, found that body weight, measured by body mass index, corresponds with when we eat and how often we eat. Specifically, people who eat larger breakfasts and adopt an 18-hour overnight fast, say from 1 p.m. to 7 a.m., have the lowest body weights. Those who ate more than three meals, or three meals plus snacks, had higher BMIs. Those who ate later in the day, after 6 p.m., compared to having the largest meal at breakfast or lunch, had higher body weights.
The Loma Linda University researchers hypothesize that 18- to 19-hour overnight dietary fasts reboot our metabolisms to help our bodies burn calories efficiently. Lead author Dr. Hana Kahleova, director of clinical research at the nonprofit Physicians Committee, says this process ensures our energy intake correlates with energy output, instead of energy reserves — or enlarged fat cells. Contrary to popular belief, these extended overnight fasts seem to help boost metabolic function.
Kahleova also finds meals consumed in the evening, compared to those eaten in the morning, result in a hyperglycemic response, or elevated blood sugar, which happens when insulin can’t process glucose into energy. Like a clog in a machine, extra glucose slows our bodies’ metabolic process down. If glucose can’t covert into energy, the sugar molecules start to populate outside of the muscle cells. Over time, this energy surplus creates an inflammatory state defined as insulin resistance. Insulin resistance is often a precursor to metabolic syndrome — aka an expanded waistline, high triglycerides, high fasting blood sugar, high blood pressure and low levels of “good” HDL cholesterol. The American Heart Association projects this series of heart disease risk factors affects nearly 1 in 4 adults. It increases the risk for a heart attack and Type 2 diabetes.
So what does this mean for you? Depending on your goals and health status, you may consider rearranging your meals so you consume more calories in the morning when insulin function is most efficient. So, let’s say you consume 1,500 to 1,800 calories a day. Instead of splitting 500 to 600 calories evenly at each meal, you could experiment with eating 600 to 700 calories for breakfast, 600 to 700 calories for lunch and a light 300- to 400-calorie dinner.
If you’re looking to lose 10 pounds or reverse the early stages of Type 2 diabetes, the 18- to 19-hour overnight fast might work well for you. This could mean eating a larger breakfast, a medium-sized lunch and no dinner at all. Instead of intermittent fasting, or alternating days of eating low-calorie meals with standard fare, you could experiment with skipping one meal each day. This enables your cells to recharge and use all the available fuel, ensuring insulin function remains at its peak the next morning.
Of course, this semi-intermittent fasting approach isn’t for everyone. People who maintain highly active lifestyles, for instance, and need adequate fuel to power morning runs or help muscle fibers recover from intense evening workouts like weightlifting might not benefit. People who are underweight or are prone to disordered eating, too, should be careful not to take such findings too far. Still, the concept provides a glimpse into how our bodies utilize fuel efficiently.
A more moderate application of this research may be to institute celebratory brunches or breakfasts instead of holiday dinners and evening birthday parties to support long-term weight maintenance. After all, previous research has shown that breakfast increases satiety, reduces total energy intake and sets us up to make better food choices throughout the day, likely because we start out with better breakfast options like fiber- and nutrient-dense foods. Plus, the researchers cite studies that find breakfast stabilizes blood sugar and improves insulin sensitivity at subsequent meals.
[See: High-Protein Breakfast Ideas.]
As Kahleova told me, the ancient advice to eat breakfast like a king, lunch like a prince and dinner like a pauper has new science behind it. She prescribes this approach, along with plant-based eating patterns and daily exercise, as a blueprint for those struggling with extra weight and sluggish metabolisms. The approach, she finds, works remarkably well for those eager to reach and maintain a healthy body weight.
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