Sometimes science quantifies something many of us know to be true. So listen up, new parents: Waking up repeatedly to care for a little one isn’t good for your moods and your ability to attend to tasks, and it’s just as bad as not sleeping much at all.

So if you get up in the morning feeling more exhausted than when you went to bed, you’ve got research on your side.

Researchers at Tel Aviv University in Israel tracked 58 young adults in two groups: those who got four hours of sleep and those who got eight but had that sleep repeatedly interrupted by tasks of at least 10 minutes — not unlike waking to feed or soothe an infant, or dealing with work during an on-call shift.

“Vast proportions of the population experience night wakings regularly due to occupational demands, environmental circumstances or the very common parental need to tend to a child during the night,” the researchers wrote recently in the journal Sleep Medicine.

They cited a study of nearly 30,000 parents in 11 countries that showed about a quarter wake up twice a night with their children up to age 3, and an additional 19.5 percent reported an average of three or more night wakings.

Such interruptions “disrupt the natural sleep rhythm. The impact of such night wakings on an individual’s daytime alertness, mood and cognitive abilities had never been studied,” Avi Sadeh, a professor at the university’s School of Psychological Sciences said in a statement. Sadeh directs a sleep clinic at the university.

“Our study demonstrates that induced night wakings, in otherwise normal individuals, clearly lead to compromised attention and negative mood.”

Sadeh and colleagues monitored sleep of volunteers in their homes. The participants wore wristwatch-style devices that could detect sleep and wakefulness.

The interrupted sleep “leads to significant negative effects on mood and sustained attention, which are indistinguishable from those results from sleep restriction of four hours per night,” the researchers wrote.