ALL I HEAR ABOUT ARE DIETS, DIETS, AND DIETS. But what if I told you that there is a way to lose weight without appealing to a restrictive diet? Imagine that you could lose weight by simply lying in bed.

Maybe I have oversold it as there is a catch: You have to be asleep. Historical studies inform us that if we put you in a sleep lab and limit your sleep to four or five hours nightly, you will consume more calories the following day.

But why do we eat more when we are sleep-deprived? Is it the fatigue that drives us, or is it something else? Will we decrease our caloric intake if we sleep more?

Thanks to a recently published study from the University of Chicago (USA), we have some answers.

Sleep and weight: Study details

Sleep expert Dr. Esra Tasali and colleagues randomized 80 overweight volunteers getting less than 6.5 hours of sleep per night to receive either personalized sleep recommendations (to extend sleep) versus nothing but routine study visits.

Here’s where we need to take a detour, as I want to share with you the very doable suggestions offered by the researchers:

• Create a bedtime routine
• Limit television and phone use in bed
• Decrease ambient light
• Decrease caffeine intake
• Increase exercise

One more thing — each study participant got a goal bedtime and wake-up time.

Sleep recommendations work

Did these sleep recommendations work? Yes. Following a two-week run-in, the intervention group slept 1.2 hours more (as shown by sleep monitors worn on their wrists).

Moreover, the sleep extension group had higher subjective scores in obtaining sufficient sleep, daytime energy and alertness, and better mood (compared with the control group).

Sleep, energy balance, and weight

The researchers scrutinized the energy balance of the subjects — calories in and calories out — using labeled water to measure. The findings are provocative:

The group randomized to sleep longer had decreased total energy intake (calories in), dropping by about 150 calories daily. They had no change in total energy expenditure (calories out).

This energy intake decrease translated to a one-pound loss over the two-week study period.

Sleep and weight — My take

This study is well-done. I love the randomized design and how the researchers measured energy intake and output objectively instead of depending on self-reporting of dietary intake.

In addition, the researchers used a validated tool to track sleep. The study authors excluded those with insomnia and sleep apnea.

Is the study perfect? We don’t know if the results apply to non-overweight individuals. Can the intervention group participants maintain their healthy sleep habits over a more extended period?

This well-done study reminds us of the importance of optimizing our sleep duration for obesity risk reduction. The strategies employed in the study are doable for many of us.