Research concluded that fasting for at least a regular 14 hours daily boosts overall health. This time restricted eating (TRE) is closer to how our hunter-gatherer ancestors would have eaten
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A leading international expert reviewed 250 studies and concluded that fasting for at least a regular 14 hours daily boosts overall health.
This time restricted eating (TRE) is closer to how our hunter-gatherer ancestors, who did not have access to snacks around the clock, would have eaten.
One study suggested eating for the same period between 6am and 3pm and a 15-hour overnight fast works best with our natural body clock – or circadian rhythm.
It boosted how the body processed blood sugar and participants also lost weight, shed dangerous visceral fat around the midriff and reduced inflammation.
Another clinical trial found eating more calories for breakfast than during later meals saw women lose 5.1kg more weight over a 12-week period.
The research, presented at the European Congress on Obesity in the Netherlands, showed eating earlier also boosted healthy gut bacteria, which affects the immune system and overall health.
Dr Courtney Peterson, co-director of the Circadian Research Core at the University of Alabama, USA, said: “So you might see this data and say ‘great, I won’t eat late at night’.
“But we usually define intermittent fasting as fasting for at least 14 hours at a time.
“Time restricted eating is becoming wildly popular.
“People typically eat within something like an eight to 10 hour window and so they’re effectively fasting for 14 to 16 hours a day.
She added: “Data suggests that eating earlier in the day improves weight loss, glycemic control, appetite, insulin resistance and fertility.”
A study by Dr Peterson’s team found people were less hungry when eating on a 8am-2pm regime than on a six-hour eating window later in the day.
They concluded a mechanism is better regulated appetite, rather than increased energy expenditure by early-risers.
A second study by Dr Peterson shows how a 8am-2pm eating regime boosts gene expression and hormone levels, which could explain its anti-aging effects seen in animal studies.
Data from around 80 animal studies suggests time restricted eating could help people live longer.
A third human study, also by Dr Peterson, of prediabetic men showed eating dinner before 3pm produced health benefits independent of weight loss.
The research review found changing our “eating hours” triggered a form of “metabolic jetlag” by making the body process food at a time of day it was not used to.
Eating just a couple of hours earlier in the evening was not enough to have a health benefit.
Dr Peterson said shifting the last meal of the day between three and five hours early was enough to boost health.
She said: “Some of the recent studies where they’ve tested having people eat in a 12-hour window and fast for 12 hours a day haven’t found any additional benefits.”
Dr Paterson said the evidence suggests that skipping breakfast only had a detrimental impact on health if it meant participants ate their evening meal later.
“One of the common hypotheses is that maybe it’s not so much that breakfast skipping is the issue, it’s that eating throughout the day is the problem.
“There is data in humans that suggests grazing throughout the day increases the odds of having obesity by 57%.
“After all, our hunter gatherer ancestors probably mixed periods of feasting with periods of fasting.”
Prof Naveed Sattar, metabolic medicine expert at Glasgow University, said: “There is some evidence that when in the day people eat might be of some importance to their health as there is a definite link between appetite control and circadian rhythms.
“However it is most likely that those that eat irregularly or eat late at night take in more calories overall due to poorer appetite control and it is the extra calories that largely determine greater weight gain and related risks.”