Eating breakfast, lunch and dinner on most days is linked with a healthier weight in later life. In a Healthcare study of 3,559 South Korean adults aged 65 and over, published online 2 October 2026, those who regularly ate all three meals had 39% lower odds of obesity than those who regularly ate two or fewer of them.
Key takeaways
- A 2026 study in Healthcare (Park, Jeong and Song) analyzed 3,559 adults aged 65 and over from the Korea National Health and Nutrition Examination Survey, 2019 to 2021. It is cross-sectional, so it shows a link, not cause.
- Regularly eating all three meals, each 5 to 7 times a week, was linked with 39% lower odds of obesity and 34% lower odds of a large waist, compared with regularly eating two or fewer of them.
- Compared with eating each meal 4 or fewer times a week, regular dinner was linked with 49% lower odds of obesity and regular breakfast with 36% lower odds. The authors caution that this does not show one meal matters more than another.
- In a 2017 Current Biology lab study of 10 young men, moving all three meals 5 hours later delayed their blood sugar (plasma glucose) rhythm by about 5.7 hours.
- The one change: give breakfast, lunch and dinner set times and keep them on most days of the week.
What did the 2026 meal regularity study find?
Older adults who ate all three meals most days were less likely to have obesity. The link held after the researchers adjusted for age, sex, income, education, marital status, smoking, alcohol, physical activity, high blood pressure and diabetes.
Each participant reported how many times a week, over the past year, they ate breakfast, lunch and dinner. Eating a meal 5 to 7 times a week counted as regular; 4 or fewer did not. Obesity meant a body mass index of 25 or more (the Asian cutoff), and a large waist meant 90 cm or more for men and 85 cm or more for women.
| Regular eating pattern (5–7 times a week) | Odds of obesity | Odds of a large waist |
|---|---|---|
| All three meals (vs two or fewer) | 39% lower | 34% lower |
| Breakfast (vs 4 or fewer times a week) | 36% lower | no clear link |
| Lunch (vs 4 or fewer times a week) | weaker link that faded after a stricter statistical check | 33% lower |
| Dinner (vs 4 or fewer times a week) | 49% lower | no clear link |
The figures are adjusted odds from the study’s fully adjusted model, and each meal was tested in a separate model.
Most of the group already ate regularly: 2,922 of the 3,559 participants ate all three meals most days. Among them, about 35% had obesity, against about 45% in the groups who ate fewer meals regularly (survey-weighted figures, before adjustment).
Why would meal regularity matter to the body clock?
Meals act as a timing signal for the clocks in your organs. Light sets the master clock in the brain, but when you eat helps set clocks in tissues such as fat and liver, which handle the food you take in.
In a 2017 Current Biology study at the University of Surrey (Wehrens, Johnston and colleagues), 10 healthy young men lived for 13 days in a lab. They ate three meals at 5-hour intervals, first starting half an hour after waking, then for six days starting five and a half hours after waking. The late schedule pushed their blood sugar (plasma glucose) rhythm about 5.7 hours later and a clock gene rhythm in their fat tissue about 1 hour later, while melatonin and cortisol, markers of the master clock, did not move.
The study was small and did not look at weight. What it shows is that the timing of meals sends a message to the body’s clocks. When meals land at different hours each day, or come and go, those clocks get mixed signals.
What do heart experts say about regular meals?
The American Heart Association’s 2017 scientific statement on meal timing and frequency (St-Onge and colleagues) concluded that irregular eating patterns appear less favorable for keeping a healthy weight and cardiometabolic health. The authors suggested a more intentional approach: planning when you eat, eating a larger share of the day’s food earlier, and keeping a consistent overnight fast.
That fits the 2026 result, though neither proves that eating regularly causes a healthier weight.
What are the limits of the study?
It is a snapshot, so it cannot show which came first. The authors note that some older adults with obesity or diabetes may have changed their meals on purpose, which would reverse the arrow. Meals were self-reported, the questions counted how often each meal was eaten rather than at what clock time, and about a third of eligible participants (1,726 of 5,285, or 32.7%) were left out for missing data. Regular eating also says nothing about what was on the plate, and the results may not carry over to other ages or food cultures.
What is the one change to make?
Give your three meals set times and keep them on most days of the week, weekends included. The 2026 study did not test this step; it is a practical way to act on what it and the meal timing research found.
- Pick a breakfast time within an hour or so of waking, and keep it.
- Set lunch about 4 to 5 hours later and dinner about 5 to 6 hours after that.
- Finish dinner 2 to 3 hours before bed, so the overnight fast is steady from night to night.
- If a meal has to move, move it by less than an hour rather than skipping it.
If you live with diabetes or another condition where meal timing matters, plan any change with your clinician. More on the last meal of the day: Best Time to Eat Dinner? What the Evidence Says. Meals anchor a steady week the way a fixed wake time does: How to Fix Your Sleep Schedule: Anchor, Light, 15 Min. Working nights? See Night Shift Schedule: How to Plan Sleep, Meals and Light. Curious when your own body clock runs? Take the Body Clock Type quiz.
Your day on My BodyClock
The day above on My BodyClock is built on three fixed meals: breakfast at 7:30 AM, lunch at 12:30 PM and dinner at 6:30 PM. A 6:30 AM wake time and a 10:30 PM bedtime frame the day, a morning walk and an after-lunch walk add daylight, and the kitchen closes about three hours before sleep. The same meal times hold on weekends.
Build your own week of steady meals in Owaves: My BodyClock on the App Store, or join the Android waitlist.
FAQ
Is it bad to skip meals?
In the 2026 study of 3,559 adults aged 65 and over, regularly eating all three meals was linked with 39% lower odds of obesity than regularly eating two or fewer of them. The study is cross-sectional, so it shows a link, not proof that skipping meals causes weight gain.
Does eating at the same time every day help your body clock?
Meal times help set the clocks in organs such as the liver and fat tissue. In a 2017 lab study, moving meals 5 hours later delayed blood sugar rhythms by about 5.7 hours, so steady meal times send the body clock a steady signal.
Is skipping breakfast linked with weight?
In the 2026 study, eating breakfast 5 to 7 times a week was linked with 36% lower odds of obesity in older adults than eating it 4 or fewer times. The American Heart Association has noted similar links in other studies, but none of them proves cause.
How many hours should there be between meals?
There is no single rule. A simple pattern is lunch about 4 to 5 hours after breakfast and dinner about 5 to 6 hours after lunch, with dinner finished 2 to 3 hours before bed.
Sources
- Park HE, Jeong KE, Song HY. Association Between Meal Regularity and Obesity Among Korean Older Adults: A Population-Based Study Using KNHANES VIII. Healthcare (Basel), 2026;14(19):3278, published online 2 October 2026. doi:10.3390/healthcare14193278. https://doi.org/10.3390/healthcare14193278
- Wehrens SMT, Christou S, Isherwood C, et al., Johnston JD. Meal Timing Regulates the Human Circadian System. Current Biology, 2017;27(12):1768-1775. doi:10.1016/j.cub.2017.04.059. https://pmc.ncbi.nlm.nih.gov/articles/PMC5483233/
- St-Onge MP, Ard J, Baskin ML, et al. Meal Timing and Frequency: Implications for Cardiovascular Disease Prevention: A Scientific Statement From the American Heart Association. Circulation, 2017;135(9):e96-e121. doi:10.1161/CIR.0000000000000476. https://pmc.ncbi.nlm.nih.gov/articles/PMC8532518/
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