Even after sleeping only 3.5 hours a night for three nights, young men burned the same total amount of energy and used the same mix of carbs and fats as when they slept 7 hours.

Scientific Claim

Three nights of shortened sleep (3.5 hours per night) in healthy young men did not cause a significant change in total 48-hour energy expenditure (3717 vs. 3741 kcal/d, p=0.508) or respiratory quotient (0.883 vs. 0.885, p=0.519), indicating no measurable effect on overall metabolic rate or fuel utilization.

Original Statement

“Sleep restriction did not affect total EE or substrate utilisation. The 48-h total energy expenditure (TEE) did not differ significantly between the 7-h and 3.5-h sleep conditions (p = 0.508). The 48-h respiratory quotient (RQ) values did not differ significantly between sleep conditions (p = 0.519).”

From study:Effect of shortened sleep on energy expenditure, core body temperature, and appetite: a human randomised crossover trial

Evidence Quality Assessment

Claim Status

appropriately stated

Study Design Support

Design supports claim

Appropriate Language Strength

definitive

Can make definitive causal claims

Assessment Explanation

The RCT with precise, continuous calorimetry provides high-quality evidence to support definitive language. The p-values clearly indicate no effect, and the sample size was powered to detect differences.

Evidence from Studies

Supporting (1)

Effect of shortened sleep on energy expenditure, core body temperature, and appetite: a human randomised crossover trial

Randomized Controlled Trial

Human

2017 Jan 10

The study found that sleeping only 3.5 hours a night for three nights didn’t change how many calories the body burned or what type of fuel it used, even though people felt hungrier.

Contradicting (0)

No contradicting evidence found

Source Study

Effect of shortened sleep on energy expenditure, core body temperature, and appetite: a human randomised crossover trial

Score: 46

DOI: 10.1038/srep39640

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