Dieters have been going about weight loss all wrong, experts have suggested.
Many people seeking to lose weight have merely been focusing on what they eat.
But, when a person eats is just as important as what they eat, scientists discovered.
The body’s metabolism is highly regulated by a person’s biological – or circadian – clock.
And when people eat out of sync with their circadian clocks, it can send their metabolism spiraling – increasing their risk of obesity and diabetes.
The findings suggest four hours after sunrise is the most opportune time to eat – identifying it as the time when fat and sugar burning were at optimum levels.
That’s why, when it comes to weight loss, ‘the outcome depends not only on what you eat but also on when you eat it,’ said Dr Gad Asher, of the Weizmann Institute of Science.
Circadian clocks are found in all living things – from bacteria to flies and humans.
Those clocks regulate rhythms of sleep, activity, eating and metabolism in every living thing.
Dr Asher said: ‘In a sense, it’s like a daily calendar, telling the body what to expect so it can prepare for the future and operate optimally.’
Scientists looked for circadian changes in mitochondria, which are cells’ power plants, that create peaks and dips in the cells’ energy levels to regulate their day-night cycle.
The team identified and quantified hundreds of mitochondrial proteins – and found that the quantities of 40 per cent peak once a day.
They also identified the proteins that make up the mitochondrial circadian click that regulates those activities.
Most of the circadian proteins were found to have peaked four hours into the daylight part of the cycle.
The researchers also uncovered a key enzyme that determines the rate of sugar use for energy production.
The enzyme reaches its maximal amount four hours into daylight – which suggests that the mitochondria’s capacity to burn sugar peaks around that time, as well.
The scientists provided mitochondria with sugar, and found that at hour four, respiration and glucose utilization were at their highest.
And, the protein responsible for the entry of fatty acids into the mitochondria only peaked at the 18th hour.
Tests found that fat processing was optimal at that same time.
The scientists also genetically modified mice with a mutation that interferes with their biological clocks.
They found that the amounts of those proteins didn’t change through the course of the day – and that decomposition activity of fats and sugars was steady.
Dr Asher said: These findings support previous findings in our lab in which we showed that if mice eat only at night, when they are active, rather than throughout the day and night, they will eat the same amount of calories but their liver lipid levels will be 50 per cent lower.
‘If we could be more aware of the timing of our cellular activities, we might be able to take advantage of various nutrients in a healthier way.’
The study was published in the journal Proceedings of the National Academy of Sciences.