How-to Guide

Chrononutrition

When is the best time to eat?

EATING TIMING

When you think about diet, it's easy to focus exclusively on what you are eating. But when you eat also has a major impact on your health. Here are some guidelines that show you how to optimize your food timing, in alignment with the latest scientific research.

When you are exposed to darkness, your brain produces a hormone called melatonin. This hormone tells cells throughout your body to do their nighttime jobs. These jobs are not suited to processing the contents of incoming food. Your biological night is when your melatonin level is raised, which occurs from about two hours before bedtime until about when you'd naturally wake up.

Eat only during your biological day

• No food within 30 minutes of your natural wake time: If you naturally wake at 7 AM, don't eat until at least 7:30 AM or later. If you have to wake up at 6:15 AM to an alarm (so earlier than normal), still don't eat until 7:30 AM or later.

• No food within two hours of going to bed: If your bedtime is 10 PM, you'll want to finish your dinner by 8 PM at the latest. You don't want to go to bed hungry though, so a good rule of thumb is to finish dinner in the two to four hours before bedtime.

• Fluids: Water and non-caloric, non-caffeinated herbal teas are fine to consume in the first 30 minutes after waking and in the two-hour pre-bed window. Manage your pre-bed fluid intake to prevent overnight urination or excessive thirst. Avoiding fluids after dinner works well for many people.

Eating Period Details

• Eating period: Consume all calories within the same 6- to 12-hour period each day. For instance, noon to 6:00 PM, or from 8:00 AM to 8:00 PM.
• Eat early: Your body tends to burn more calories after morning meals than after evening meals. What's more, your blood sugar tends to vary less dramatically after morning meals. So, many people benefit from increasing the size of their earliest meal and reducing the size of their latest one.
• Eat around physical activity: Physical activity before and after meals improves how nutrients from foods and drinks are handled by your body. So, if you have a hard training session late in the afternoon, it's fine to have a bigger dinner.

• Meal number: In general, the greater your caloric intake, the more meals you'll need. If you're an athlete who needs to consume 6,000 calories each day, don't try to do so at just two meals! But if you're a small person and need to consume 1,500 calories a day to lose fat, you'll probably find that splitting this into four meals makes each meal small enough to be unsatisfying.
• Meal spacing: Consume meals three to six hours apart. Avoid calories between meals.
• Be consistent: Eat the same number of meals at approximately the same times every day. Those who maintain this type of consistency show better metabolic health compared to those who have more erratic eating patterns.

• Stimulant timing: Don't consume caffeine within nine hours of bedtime. Consuming caffeine too late in the day can delay melatonin production and sleep timing. Caffeine can also disrupt sleep in a way that makes it less restorative. If you plan to go to bed at 10 PM, stop consuming caffeine by 1 PM. People vary in their responses to all stimulants (including medications, such as Ritalin), so pay close attention to how you respond to them.
• Alcohol timing: While alcohol may reduce how long it takes people to fall asleep, it tends to impair sleep later in the night. Alcohol also disrupts many components of people's body clocks. So, if you plan to go to bed at 10 PM, stop consuming alcohol by 6 PM.