If you’re doing my 10-Day Belly Slimdown right now, you know that one big key to success is limiting your eating to just seven hours each day—what I call mini-fasting, a.k.a. time-restricted eating or intermittent fasting.
Time-restricted eating (as scientists call it) is a cornerstone of my plan because research shows that it’s an incredibly powerful way to stay slim. And just this week, new research came out showing that it does far more. In fact, it can help you stay healthy even if you’re genetically programmed to become obese, sick, and diabetic.
Here’s the story.
The initial research I cited in my book came from a team headed by Dr. Satchidananda Panda at the Salk Institute. In the team’s early studies, they found that mice with 24-hour access to an unhealthy diet got fat and developed diabetes, fatty liver, and high cholesterol. In comparison, mice that ate the same bad diet but only had access to food for 8 to 10 hours a day stayed slim and healthy—even when they ate the same number of calories.
Dr. Panda and his team speculated that this happened because mice on the time-restricted eating plan stayed in better “sync” with their biological clocks. In both mice and humans, this clock plays a big role in metabolism. (For example, in humans, genes for digestion are more active in the daylight hours, while genes for cell repair are more active at night.)
To find out, they designed a new experiment. This time, the team disabled genes responsible for maintaining the biological clock in mice—including genes in the liver, which regulates many metabolic functions. These genetic defects made the mice prone to obesity, diabetes, fatty liver disease, and elevated blood cholesterol. Then the scientists put the mice at even higher risk by feeding them a bad diet.
Just as before, one group of mice got to pig out 24 hours a day, while a second group got the same number of calories but only had access to food during a 10-hour window. So what happened? Once again, the mice with unlimited access to food got fat and sick. But the mice eating during the 10-hour window stayed slim and healthy, even though these mice had “broken” biological clocks and thus were genetically programmed to become obese and sick.
This is a huge deal, because it means that even when our biological clocks are disrupted—by genetic defects, shift work, travel, even aging (which weakens our biological clocks)—we can still stay healthy simply by reducing our “eating window.” And it proves that genes aren’t destiny.
“Many of us may have one or more disease-causing defective genes that make us feel helpless and destined to be sick,” Dr. Panda says. “The finding that a good lifestyle can beat the bad effects of defective genes opens new hope to stay healthy.”
So if you think you’re doomed to be fat or diabetic because your parents and grandparents are, think again! Simply by cutting down on your eating window—I recommend seven hours if you want to lose belly fat quickly, and 10 to 12 hours if you’re at your ideal weight—you can keep extra pounds off AND avoid metabolic syndrome and diabetes. How awesome is that?
By the way, if you’re interested in learning more, check out mycircadianclock.org, offered by Dr. Panda’s team. You can download a free app, learn more about time-restricted eating, and even participate in the team’s research studies.
Keep thinking Big and living BOLD!