Today's three-minute lesson

Why You Feel Sleepy After Lunch

That dip in energy after lunch is often blamed entirely on eating a large meal. While what and how much you eat can affect how you feel, the afternoon slump is not simply your lunch knocking you out.

Your alertness naturally rises and falls across the day. In the early afternoon, the alerting effect of your body clock briefly dips while the pressure to sleep has been building since you woke up. Eating can make this natural dip more noticeable - a response sometimes called postprandial somnolence - but feeling a little sleepy at this time does not necessarily mean that you ate the wrong thing or need to fix it.

The problem often begins with what we do next. We reach for caffeine to push through the slump, then find that the caffeine is still in our system when we want to sleep that night. Poorer sleep leaves us more tired the following afternoon, and the cycle repeats.

A balanced lunch can help you avoid making the dip more dramatic, but you do not need to eliminate it. Notice it, perhaps even adjust your schedule around it, and accept that it is a normal part of the day.

Use movement and daylight to help you feel more alert without sacrificing tonight's sleep.