Could the timing of your breakfast and dinner help you eat less and lose body fat?
A small, preliminary study suggests it's possible.
People cut their daily calorie intake by about 25% when they held off on breakfast for 90 minutes and then had dinner 90 minutes earlier than usual, said senior researcher Jonathan Johnston. He is a reader in chronobiology and integrative physiology with the University of Surrey.
These people also lost more than twice as much body fat, on average, than a control group with unrestricted eating times, Johnston added.
"Meal timing is important, in addition to meal content," Johnston said. "Meal timing research is still quite new, but has a lot of promise to help people improve health with relatively minor changes to behaviour."
To find out, nine people were recruited to take part in a "time-restricted feeding" pilot study, in which they delayed breakfast and moved up dinner by an hour and a half. During that window, they could eat as often as they liked.
"We deliberately designed our study to have a fairly minor reduction in daily eating duration," Johnston said.
Another seven people served as a control group by eating meals as they normally would.
Participants provided blood samples and completed diet diaries before and during the study period.
A shorter meal window
After 10 weeks, the people with a shorter meal window had reduced their body fat by about 2%, compared with under 1% lost by those in the control group, the researchers said.
Participants also cut their average energy intake from roughly 2 091 to 1 553 calories per day, the findings showed.
People said they tended to eat less because they had reduced appetite, decreased opportunities to eat, or a cutback in their snacking habits, according to a questionnaire they filled out afterward.
Restricted feeding could lead you to eat food at times best suited for your body's daily metabolic rhythms, he suggested. It also could be that a shorter meal window increases the length of the daily fasting period.
However, these changes to meal timing may not be sustainable for many.
Fitting in with other people
About 57% of participants told researchers they could not have maintained the new meal times long-term, because they were incompatible with family and social life.
But 43% said they would consider continuing a time-restricted diet if eating times were more flexible.
"This is really important as it emphasizes how important it is for dietary changes to fit with people's lives in the real world," Johnston said. "An important question for future research is to evaluate whether a shortened daily duration of feeding will be effective if started at different times of day."
The study was published in the Journal of Nutritional Science.
Stress hormones can spike
According to an article by Africa Check, 26.8% of South Africans suffer from obesity. This statistic places South Africa at the top of the average Sub-Saharan African ranking.
The meal schedule in this study is a form of intermittent fasting, said Grace Fjeldberg, a registered dietitian nutritionist with the Mayo Clinic Health System. This "has become an increasingly popular trend to support weight loss," she said.
"Everyone is looking for quick ways to support weight loss and improve overall health, and eating fewer times throughout the day often produces a deficit in calories and ultimately weight loss," Fjeldberg explained.
But Fjeldberg warned that quick weight loss through fasting might not necessarily lead to better health and long-term reduced weight.
"Hunger and stress hormones can spike with prolonged periods of fasting, and for some this may mean increased portions in the few meals that are eaten throughout the day and potentially higher calories," Fjeldberg said.
Image credit: iStock