A study found that women who drastically cut food intake for weight loss and enter a state of severe energy deficit face a higher risk of suffering from sleep deprivation.

A joint research team led by Professor Park Min-Seon of the Department of Family Medicine at Seoul National University Hospital and Professor Seo Min-Jeong of the Department of Family Medicine at Seoul Boramae Medical Center announced on the 20th that they had published a study on the association between ‘Energy Intake-Expenditure Balance (EIEB)’ and sleep duration in the ‘Korean Journal of Family Medicine’. The researchers measured and analyzed the dietary habits and physical activity levels of 13,164 adults who participated in the Korea National Health and Nutrition Examination Survey.

Sleep deprivation is a major risk factor for chronic diseases such as cardiovascular disease, diabetes, and metabolic syndrome. In the study, to determine the impact on sleep of the ‘energy balance’ index, calculated by subtracting basal metabolic rate and physical activity energy expenditure from total daily energy intake, participants were divided into quartile groups 1~4 and compared.

In the analysis, among women, compared with the first quartile, which had the most severe energy deficit, the second quartile, where intake and expenditure were similarly balanced, showed a 29% lower risk of sleeping 6 hours or less per day. The third and fourth quartiles, in which daily energy intake exceeded expenditure, also had lower risks of sleep deprivation than the first quartile by 25% and 24%, respectively. The researchers explained that the greater sleep improvement seen in the second quartile, where intake and expenditure were roughly similar, compared with the fourth quartile, which had the largest energy surplus, indicates that an appropriate balance is more important than simply eating more.

In particular, among women, the sleep improvement effect of achieving energy balance was even more pronounced in those with low diet quality, those in physically active occupations, or those who did not get catch-up sleep on weekends. In contrast, no association between energy balance and sleep deprivation was observed in men.

The researchers pointed to sex differences in ‘neuroendocrine-immune regulation’ as the mechanism underlying why this association appeared only in women. The body uses about 400㎉ during sleep to activate immune cells and calm inflammation, and when energy is severely deficient, the stress axis is activated and interferes with deep sleep. In particular, women respond much more sensitively to fluctuations in hormones such as cortisol and leptin, which are related to stress responses and appetite, so when nighttime recovery energy is lacking, they suffer a greater negative impact on sleep quality than men, the team explained.

Professor Park Min-Seon said, “This study confirmed that dieting by simply eating less or only increasing exercise can actually harm sleep,” and added, “For women, maintaining ‘balance’ by eating appropriately in line with their activity level is itself a key factor for sound sleep, and to protect sleep health, personalized health management is needed that sets different energy balance targets according to sex, occupation, and activity characteristics.”