Eating breakfast earlier than 8.30am may ward off type 2 diabetes, research suggests.
The relatively common condition occurs when an individual's blood sugar rises to dangerously high levels, due to the body producing insufficient amounts of – or not responding to – the hormone insulin.
Unlike type 1 diabetes, type 2 is linked to being overweight or obese, with a healthy lifestyle known to help prevent the condition.
Scientists from Northwestern University have now revealed people who eat before 8.30am have reduced insulin resistance; when the body does not respond to the hormone.
In the UK, 3.9 million people have been diagnosed with diabetes, of whom around 90% have type 2. In the US, 34.2 million – 10.5% of the population – have diabetes; type 2 in 90% to 95% of cases.
Research into healthy eating habits has thrown up mixed results.
Some studies suggest people should consume six small meals a day, rather than a hearty breakfast, lunch and dinner.
Others recommend eating breakfast like a king, lunch like a prince and dinner like a pauper, with progressively small meals throughout the day thought to promote good health.
Fasting, where eating is restricted to a set time period, has also been linked to improved metabolic wellbeing; defined as the absence of heart disease, strokes and type 2 diabetes.
"We found people who started eating earlier in the day had lower blood sugar levels and less insulin resistance, regardless of whether they restricted their food intake to less than 10 hours a day or their food intake was spread over more than 13 hours daily," said lead researcher Dr Marriam Ali.
Insulin resistance can be a warning sign of type 2 diabetes.
Along with high blood sugar levels, insulin resistance affects a person's metabolism, which describes food being broken down into proteins, carbohydrates and fats.
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The Northwestern scientists analysed more than 10,500 adults who took part in the National Health and Nutrition Examination Survey.
"With a rise in metabolic disorders such as diabetes, we wanted to expand our understanding of nutritional strategies to aid in addressing this growing concern," said Dr Ali.
The adults were divided into three groups according to the duration of time they ate every day – less than 10 hours, 10 to 13 hours, and more than 13 hours.
Six subgroups were then created based on when food was first consumed.
The results – presented virtually at the Endocrine Society's ENDO 2021 meeting – suggest the participants' blood sugar levels did not differ across the three groups.
Insulin resistance was found to be higher, however, among those with a shorter eating interval and lower in those who ate before 8:30am.
"These findings suggest timing is more strongly associated with metabolic measures than duration, and support early eating strategies," said Dr Ali.
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