12/10/2014 10:47 am ET Updated Dec 06, 2017

It's About Time: When Is as Important as What in Eating


Remember these three letters, TRF. It won't be hard. You'll be hearing them a lot. TRF, Time-Restricted Feeding, is the new mantra in the diet, weight loss, and disease prevention world.

Stories in this arena usually deliver bad news. Either something you love to eat will kill you or something you can't stand is the new "superfood" panacea. This new research promises to be a crowd pleaser. It suggests nothing in the stop eating this and eat a lot less of everything, department. You can eat as much as you want of what you want.

So what's the catch?

Time. The kitchen is only open for 8-9 hours a day. Period. The remaining hours you are NPO (Nil per os) as they say, nothing by mouth. Yes, you can continue to swig your water bottle, assuming it's filled with water.

In 2012, Satchidananda Panda demonstrated that mice fed a high-fat diet eight hours per day were healthier and leaner than mice allowed to eat the same diet whenever they wanted, even though both groups consumed the same number of calories. Now Panda, working with colleagues at the Salk Institute, has investigated this effect under a variety of conditions that mimic the real world.

The team studied the effects of TRF with preexisting obesity and diverse diets (high fat, high sugar, high fat and sugar). TRF appeared to prevent elevated cholesterol, insulin resistance and inflammation despite the consumption of these obesity-causing diets. In other words, it seemed to block the pathological consequences of the eating habits of many Americans. The benefits were proportional to the fasting duration.

In obese mice with Type 2 diabetes, TRF reversed the progression of disease. The therapeutic effect was maintained when the mice were given the weekend off. This would be particularly salient in a human model.

These findings should not shock. TRF allows access to food during the animal's active phase of the day. Our species has thoroughly divorced itself from the natural rhythms that guided our evolution. TRF reminds us that our metabolism honors ancient circadian clocks whether or not we do. Artificial light does not fool our bodies and normalize these metabolic pathways that balance energy storage and energy utilization.

Could a daily feed-fast cycle have such profound effects?

Replicating this work in humans is the next step. The research results are so robust and the intervention so safe (unless hypoglycemia is an issue -- something to discuss with a physician before trying TRF) it seems reasonable to be optimistic. But beware. Too often this type of research is interpreted as a green light for wild dietary indiscretion. Studies have shown that after starting a statin (cholesterol lowering medication) many people feel bulletproof and their eating habits deteriorate. This new data should build on whatever positive changes you've already mastered.