We tend to fit our meals around activities: breakfast, if you eat one, at maybe 7 in the morning before work, meal breaks at noon, then after work you do a little shopping, get home, change clothes, tend to a few chores, cook up something, and sit down to dinner at 6 or 7.

Later, in front of the TV, you might have a couple of cookies or that last piece of cake.

If you don’t work away from home, you often plan your meals around the patterns of those in your household who do hold jobs or go to school; if you’re retired, those mealtimes often have become hardwired.

For years, dieticians have been encouraging us to leave a 12-hour window—for example, from 7 p.m. to 7 a.m.—in which we don’t eat. That stretch of time moves the body into a state of ketosis, in which you burn stored fat for energy. Result: you shed fat and reduce your risk of being overweight.

Now researchers at the Salk Institute are telling us to close that window even more.

In a study of mice, the scientists found that confining eating to a nine-hour window—say, from 7 to 4 or 8 to 5—not only burns fat but sparks the beneficial expression of thousands of genes across 22 regions of the body and enhances regulation of several key biological processes.

In the study, one group of mice could eat whenever they wanted. Another group ate the same diet but were given access to food only during a nine-hour period each day. After seven weeks, researchers collected tissue samples from 22 organ systems and the brains of the test subjects.

Seventy percent of the mices’ genes were activated by time-restricted eating. 

“By changing the timing of food, we were able to change the gene expression not just in the gut or in the liver, but also in thousands of genes in the brain,” Satchidananda Panda, one of the scientists, told Science magazine.

Nearly 40 percent of genes in organs important for hormonal regulation—such as the adrenal glands and pancreas—functioned more effectively as their genes were more freely expressed.  

Unbalanced hormones have been implicated in conditions from diabetes to stress-related illnesses, so time-restricted eating could help ease symptoms of such illnesses or prevent them entirely.

The research findings implied that limiting meals to a relatively small daily window also could benefit a range of illnesses from high blood pressure to cancer.

In addition, restricting meals to a sharply defined period helped mices’ organs regulate their circadian rhythm: organs, and even cells, are tuned to carry out certain functions most effectively at specific times of the day or night, often based on what others already have done. Time-restricted eating helped those processes and sequences happen more effectively and efficiently.

Next, the research team will study the effect of time-limited eating on specific diseases or conditions.

TRENDPOST: While time-restricted eating is showing more and more benefits, the developed world’s food culture of red meat, saturated fat, sugar, and over-processed foods—abetted by the global processed food industry and its advertising—will continue to drown out science’s message.

The global transition to a beneficial diet and food culture aligned with evidence will take at least two more generations. That transition will be aided by three key factors:

  • the rising cost, and reduced availability, of food in a world beset by weather extremes;
  • efforts to reel back the cost of healthcare that still is being raised by lifestyle diseases;
  • the gradual seepage of diet-related, research-based health information into public awareness.
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