Researchers at Jimma University in Ethiopia studied 427 teachers and professors to understand how sleep quality connects to body weight. They found that about one-third of the staff had poor sleep quality, and interestingly, those with worse sleep didn’t necessarily weigh more. However, the study revealed a hidden connection: poor sleep appears to affect weight through depression and unhealthy eating habits. The research suggests that improving sleep, managing mood, and making better food choices work together to help maintain a healthy weight. This finding is important because it shows weight management isn’t just about diet and exercise—mental health and sleep matter too.

The Quick Take

  • What they studied: Whether people who sleep poorly tend to weigh more, and what might explain any connection between sleep and weight
  • Who participated: 427 university teachers and staff members in Ethiopia, with an average age and mix of men and women working in academic settings
  • Key finding: Poor sleep quality showed an unexpected pattern—it was actually linked to slightly lower body weight, but this relationship worked through depression and unhealthy eating habits. About 32% of participants reported poor sleep, and 23% were overweight
  • What it means for you: If you struggle with sleep, it might affect your weight through mood and food choices rather than directly. Improving sleep, managing stress and depression, and eating better may work together to help you reach a healthy weight. However, this study shows a connection, not proof that poor sleep causes weight changes

The Research Details

Researchers recruited 427 university staff members from different departments at Jimma University in Ethiopia. They measured each person’s height and weight to calculate body mass index (BMI), which is a standard way to check if someone is at a healthy weight. They also gave participants a questionnaire—a set of questions—to learn about their sleep quality and asked about depression, anxiety, and stress. The researchers used a statistical method called structural equation modeling, which is like drawing a map to show how different factors connect to each other and influence weight.

This type of study is called cross-sectional, meaning researchers collected all the information at one point in time, like taking a snapshot. It’s different from following people over months or years to see what happens. The study used trained data collectors to measure height and weight accurately, which makes those measurements reliable.

Understanding how sleep, mood, and eating habits work together is important because it shows that weight management is more complicated than just calories in and calories out. If poor sleep affects weight mainly through depression and food choices, then doctors and health coaches might help people better by addressing all three areas together rather than focusing only on diet and exercise. This approach could be more effective for helping people reach healthy weights.

The study’s strengths include accurate physical measurements taken by trained staff and a decent sample size of 427 people. However, the study only captured information at one moment in time, so we can’t be sure if poor sleep actually causes weight changes or if something else is happening. The study was done in Ethiopia with university staff, so the results might not apply exactly the same way to other countries or different groups of people. The researchers used a reliable questionnaire for sleep quality, which adds credibility to those findings.

What the Results Show

The study found that about 32% of the university staff reported poor sleep quality. The average body mass index was 22.7, which is considered healthy, though 23% of participants had a BMI above 25, indicating they were overweight. Surprisingly, the statistical analysis showed that poor sleep quality was actually linked to a slightly lower BMI, not a higher one. However, this unexpected finding came with an important explanation: the connection between poor sleep and weight appeared to work indirectly through two pathways—depression and unhealthy eating behaviors.

When the researchers looked deeper, they discovered that poor sleep quality was associated with higher rates of depression (25.5% of participants), anxiety (44.7%), and stress (16.6%). These mental health challenges seemed to be the bridge between sleep problems and weight changes. Additionally, poor sleep was connected to eating behaviors that promote weight gain, such as eating more processed foods or eating when stressed.

The statistical relationship was modest but meaningful (β = -0.08, P = 0.042), meaning the connection was real but not extremely strong. This suggests that while sleep quality matters for weight, it’s just one piece of a larger puzzle that includes mental health and food choices.

The study revealed high rates of mental health challenges among the academic staff. Nearly half reported anxiety symptoms, and a quarter experienced depression. These mental health issues appeared to be important factors in how sleep quality affected weight. The research also highlighted that unhealthy eating behaviors—what researchers called ‘obesogenic dietary behavior’—played a significant role in the relationship between sleep and weight. This suggests that when people sleep poorly, they may turn to comfort foods or eat more frequently, which can contribute to weight gain.

Previous research has generally shown that poor sleep is linked to weight gain and obesity, especially in developed countries. This study’s finding of an inverse relationship (where poor sleep was linked to lower weight) is unusual and suggests that the connection between sleep and weight may be more complex than previously thought. The finding that depression and eating habits mediate this relationship aligns with growing research showing that mental health is a crucial factor in weight management. The study adds to evidence that in some populations, the sleep-weight relationship may work differently than expected, possibly because of cultural factors, work stress, or other environmental influences specific to the study setting.

This study has several important limitations to consider. First, it only collected information at one point in time, so researchers cannot prove that poor sleep causes weight changes—only that they occur together. Second, the study only included university staff in Ethiopia, so the findings might not apply the same way to other countries, different age groups, or people in other types of jobs. Third, participants self-reported their sleep quality through questionnaires, which means their answers might not be perfectly accurate—people sometimes remember or describe their sleep differently than it actually was. Fourth, the study didn’t measure all possible factors that could affect weight, such as physical activity levels, total calorie intake, or genetics. Finally, the unexpected finding that poor sleep was linked to lower weight (rather than higher) is surprising and needs to be confirmed by future research before we can be confident in this result.

The Bottom Line

Based on this research, consider these evidence-based approaches with moderate confidence: (1) Prioritize sleep quality by maintaining a consistent sleep schedule and creating a good sleep environment—this may help your overall health and mood. (2) Pay attention to your mental health, especially depression and anxiety, as these appear to influence both sleep and weight. Consider talking to a counselor or therapist if you’re struggling. (3) Be mindful of your eating habits, especially when stressed or tired, since poor sleep may lead to unhealthy food choices. (4) Combine these approaches together rather than focusing on just one—sleep, mental health, and nutrition work together. These recommendations are based on one study in a specific population, so individual results may vary.

This research is most relevant to adults who work in demanding jobs, experience poor sleep, or struggle with weight management. It’s particularly important for people dealing with depression, anxiety, or stress, as these conditions appear to be key connections between sleep and weight. University staff and other professionals with irregular schedules should pay special attention. However, this study was done in Ethiopia with a specific group, so people in other countries or different life situations should be cautious about applying these findings directly. If you have a medical condition, take medications, or have significant mental health concerns, talk to your doctor before making major changes based on this research.

Improvements in sleep quality and mood typically take 2-4 weeks to become noticeable, though some people see changes sooner. Weight changes usually take longer—expect 4-8 weeks to see meaningful differences if you’re making multiple lifestyle changes together. Mental health improvements from therapy or counseling often take 6-12 weeks to become apparent. Remember that these timelines vary greatly between individuals, and consistency matters more than quick results.

Want to Apply This Research?

  • Track three connected metrics daily: (1) Sleep quality on a scale of 1-10 and total hours slept, (2) Mood rating and any anxiety or stress levels, (3) Eating patterns, noting when you eat and whether choices were healthy or stress-related. This reveals how these three factors influence each other over time.
  • Start with one practical change: set a consistent bedtime and wake time, even on weekends, for two weeks. Then add a second change: identify one unhealthy eating habit triggered by poor sleep or stress and replace it with a healthier option. Finally, incorporate a stress-management activity like a 10-minute walk or breathing exercise when you feel anxious. Track how these changes affect your sleep quality and mood.
  • Use a weekly review approach: every Sunday, look back at your sleep, mood, and eating patterns to identify patterns. Notice which days had the best sleep and what you ate on those days. Track your weight weekly (same day, same time) rather than daily, as daily fluctuations can be misleading. After 8 weeks, compare your baseline measurements to see if the combined approach is working for you.

This research describes associations between sleep quality and weight in a specific population in Ethiopia and should not be interpreted as medical advice. The study shows a connection between these factors but does not prove that poor sleep directly causes weight changes. Individual results vary greatly based on genetics, medical conditions, medications, and other factors. Before making significant changes to your sleep habits, diet, or mental health treatment, consult with your healthcare provider or a qualified medical professional. If you experience symptoms of depression, anxiety, or other mental health concerns, seek help from a mental health professional. This information is for educational purposes and is not a substitute for professional medical diagnosis or treatment.