You are when you eat: Scientists recommend a ten-hour window for daily dining

October 10, 2022

Although many of us tend to feel like what we eat has a greater impact than when we eat it, it’s important to remember that our bodies digest food differently at various times of the day. Eating a majority of your calories earlier in the day and limiting how much you eat later in the evening or through the overnight hours may help your body to digest food more efficiently, reports Healthline.

It may also reduce your risk of certain risk factors for metabolic conditions like diabetes and obesity.

Many of these risk factors are related to circadian rhythm, the cycle that moderates our sleep-wake patterns in reaction to changes in light over a 24-hour period. We usually think of circadian rhythms as affecting how tired or awake we feel, but they also influence other physical, mental, and behavioral processes in the body–including eating and digestion.

Conversely, mealtimes influence circadian rhythm. Thus, our eating habits and circadian rhythms constantly interact, although some scientists remain unsure as to exactly how much.

Still, researchers have found associations between circadian rhythm, mealtimes, weight status, and even insulin resistance, a hallmark of metabolic conditions like obesity and diabetes. In fact, repeated disruptions to normal circadian rhythms, such as those that happen when you travel between time zones or pull an all-nighter, may increase your risk of developing a metabolic condition.

For example, a recent study of 31 police officers found that officers consumed more calories during night shifts than day shifts. Other studies have linked night shifts with irregular meal patterns, poorer diet quality, and an increase in metabolic risk factors.

Mealtimes and digestion interact with natural processes in the body, such as circadian rhythm. Timing meals and digestion in a way that avoids disruption of these other processes tends to yield better health outcomes.

Keeping a consistent meal schedule from day to day is linked to weight loss, an increase in energy, and a reduction in metabolic risk factors for chronic disease.

Still, eating at the same time every day may not always be doable, so it’s best not to take a one-size-fits-all approach to mealtimes.

What’s more, individual genetics affect much of how our bodies regulate circadian rhythms that interact with mealtimes. Thus, there’s no single best mealtime schedule for everyone, and it may take some trial and error to discover the best mealtimes for you.

Here are some guidelines to keep in mind when scheduling your meals.

  • Eat earlier when possible. Many studies have linked earlier mealtimes to better health outcomes, compared with eating late at night.
  • Limit your daily window of eating. Keeping your entire caloric intake for the day within a ten-hour time frame reduces the risk that digestion will interfere with your body’s circadian rhythm.
  • Consider your circadian rhythm. Your body may not digest and process your meals as efficiently while it’s also releasing melatonin —specifically, late in the evening or during the very early morning hours.
  • Health conditions. Many medications must be timed with meals and may dictate when you need to eat. Conditions such as diabetes also require eating at certain times of the day to maintain proper blood sugar levels.
  • Your daily routine. We often time our meals around work schedules and personal obligations. That may mean eating earlier or later than you would ideally like to. In this case, maintaining consistency may still help limit disruptions to your circadian rhythm.
  • Type of meal. On days when you have no choice but to eat later in the evening, choosing small, nutrient-dense, yet simple meals can aid digestion and limit circadian rhythm disruptions.
  • Your instincts. Mealtimes will likely fluctuate from day to day. It’s important to trust your instincts and allow yourself to eat when you’re hungry, even if it’s at a different time of the day than you planned.

Hence, the best times of day to eat will vary from person to person—and maybe even from day to day. Consider eating the bulk of your calories earlier in the day and try to avoid eating within a few hours of bedtime.

Research contact: @Healthline