Recent studies indicate that when we eat may be as relevant as what we eat. To extend the daily fasting period may override the negative health effects of a high-fat diet and prevent obesity, diabetes and liver disease in mice, according to scientists at the Salk Institute for Biological Studies.
Science Daily reported that mice limited to eating during an 8 hours period were healthier than mice that ate freely throughout the day, regardless of the quality and content of their diet. The aim of the study was to determine whether obesity and metabolic diseases came from a high-fat diet or from disruption of metabolic cycles. (The Wall Street Journal had much to say about the importance of when we eat.)
“It’s a dogma that a high-fat diet leads to obesity and that we should eat frequently when we are awake,” says Satchidananda Panda, an associate professor in the Regulatory Biology Laboratory and senior author of the paper. “Our findings, however, suggest that regular eating times and fasting for a significant number of hours a day might be beneficial to our health.”
After 100 days, mice who ate fatty food frequently throughout the day gained weight and developed high cholesterol, high blood glucose, liver damage and diminished motor control, while the mice in the time-restricted feeding group weighed 28 percent less and showed no adverse health effects despite consuming the same amount of calories from the same fatty food. Further, the time-restricted mice outperformed the ad lib eaters and those on a normal diet when given an exercise test.
“This was a surprising result,” says Megumi Hatori, a postdoctoral researcher in Panda’s laboratory and a first author of the study. “For the last 50 years, we have been told to reduce our calories from fat and to eat smaller meals and snacks throughout the day. We found, however, that fasting time is important. By eating in a time-restricted fashion, you can still resist the damaging effects of a high-fat diet, and we did not find any adverse effects of time-restricted eating when eating healthy food.”
Hatori cautioned that people should not jump to the conclusion that eating lots of unhealthy food is all right as long as we fast. “What we showed is under daily fasting the body can fight unhealthy food to a significant extent,” she says. “But there are bound to be limits.” (Emphasis mine.)
I have written repeatedly about the damages from obesity and how it is a major health challenge. The Centers for Disease Control report that more than a third of American adults and 17 percent of youth are obese.
I stand by my mantra of eat less;move more; live longer, but it seems to be good news that spreading of caloric intake through the day may contribute, as well, by perturbing metabolic pathways governed by the circadian clock and nutrient sensors.
“The take-home message,” says Panda, “is that eating at regular times during the day and overnight fasting may prove to be beneficial, but, we will have to wait for human studies to prove this.”
He added that most successful human lifestyle interventions were first tested in mice, so he and the team are hopeful that their findings will follow suit.
If adhering to a time-restricted eating schedule can prevent weight gain by 10 to 20 percent, it will be a simple and effective lifestyle intervention to contain the obesity epidemic.