Many of us lead busy lives that cause us to skip breakfast and push dinner to late at night. But a massive observational study recently published in the Endocrine Society’s journal, the world’s largest organization of physicians and scientists focused on hormones and bone health, found a significant link between those habits and a higher risk of osteoporotic fractures.
The study, led by Dr. Hiroki Nakajima of Nara Medical University in Japan, analyzed data from 927,130 adults. The findings showed that skipping breakfast more than 3 times a week was associated with an approximately 18% higher risk of osteoporotic fractures. Eating dinner less than two hours before bedtime at a similar frequency was linked to an approximately 8% increase in risk.
The most striking finding involved those who combined both habits. Skipping breakfast and eating late dinners was associated with a roughly 23% higher risk of osteoporotic fractures, such as hip, vertebral or forearm fractures.
For comparison, within the same research model, smoking was associated with an approximately 11% increase in fracture risk, while “adequate sleep” was linked to a modest 5% reduction in risk. The researchers cautioned against drawing sweeping comparisons between different lifestyle factors, but the numbers point to a clear trend.
Why does it happen?
Nakajima described the pattern as a “domino effect” of accumulated habits. People who skip breakfast and have late dinners tend to adopt other unhealthy behaviors. In the study, that group had higher rates of smoking and daily alcohol consumption, along with lower levels of physical activity and fewer hours of sleep.
Late-night eating is also believed to disrupt sleep quality and the body’s internal clock. It may be associated with changes in stress hormones such as cortisol and increase processes that damage bone. Skipping breakfast may also mean missing a key daily opportunity to consume calcium and vitamin D, which are critical for skeletal strength.
Still, the researchers stressed that this was a retrospective observational study. It demonstrates a statistical association but cannot prove direct causation.
The risk for ‘night owls’
The impact of biological rhythms and lifestyle extends to heart health as well. A separate study based on UK Biobank data followed about 322,000 people over 14 years. It found that “night owls,” those who tend to stay awake and active late into the night, were 79% more likely to have poor cardiovascular health indicators compared with people active mainly during the day.
Moreover, night-oriented individuals showed a 16% higher risk of a first heart attack or stroke compared with people with average sleep patterns. By contrast, “morning types” had a 5% lower risk. Here, too, the leading explanation is a mismatch between the internal biological clock and the external environment, combined with a more sedentary lifestyle and poorer diet.
The bigger picture: Why global health officials are concerned
The scale of the findings becomes clearer in light of data from the World Health Organization (WHO) and the International Osteoporosis Foundation. According to estimates, one in three women and one in five men over age 50 will experience an osteoporotic fracture in their lifetime. When a condition is this common, a 23% added risk linked to meal timing could affect millions.
The picture is similar for "night owls" and heart health. Cardiovascular disease is the leading cause of death worldwide, claiming about 17.9 million lives each year, according to the WHO. Given such a high baseline risk, a 16% increase among people who routinely stay up late carries major public health implications.
Together, the two studies echo a central warning from the WHO in recent years: The epidemic of chronic diseases in the 21st century is driven largely by modern lifestyles. Irregular eating patterns, circadian disruption, insufficient sleep and sedentary behavior are not merely problematic habits. They are key risk factors shaping both quality of life and life expectancy.
First published: 08:56, 02.24.26