Many people follow a pattern of constant eating throughout the day, forcing the body to continually pump out insulin, and metabolize a steady stream of food. It turns out, it’s not just what we are eating that makes a difference in our health, but rather when we are eating.
A small pilot study published Wednesday in the Journal of Nutritional Science shows that a time-restricted feeding approach helps reduce body fat, without counting calories.
The 10-week study by British researchers split healthy individuals into two groups — those who consumed breakfast 90 minutes later and dinner 90 minutes earlier — and those who followed their normal eating routine. Both groups kept food diaries and gave blood samples during the 10 weeks.
There were no restrictions on what the two groups could eat.
At the end of the intervention period, participants in the time-restricted feeding group, who reduced their eating times by 4 ½ hours, had lost body fat, reduced total caloric intake, and had modest improvements in metabolic risk factors like LDL cholesterol. In a 10-week period, the time-restricted eating schedule accomplished what many popular diets cannot — fat loss.
What is time-restricted feeding?
It's not about counting calories.
It's not even about changing what you eat, but shortening the window of total eating throughout the day. Many of the patients I work with adhere to a time-restricted eating pattern by stopping eating by 6:00 pm, or focusing on having dinner early, and omitting calories later in the evening. Participants in the University of Surrey study had a hard time sticking to the restrictive timing of their meals, although 43 percent said they would consider continuing the program if eating times were more flexible.
"As we have seen with these participants, fasting diets are difficult to follow and may not always be compatible with family and social life," lead researcher Dr. Jonathan Johnston said in the news release. "We, therefore, need to make sure they are flexible and conducive to real life, as the potential benefits of such diets are clear to see."
This challenge is something I see in many of my patients as well, many of which will combine both intermittent fasting practices — fasting a few nonconsecutive days a week — with a few days of time restricted feeding as an easier approach.
Though the findings of the current trial are early, and more large, human studies are need to be completed, the results do follow previous research looking at fasting as a whole to improve weight and health.
Time-restricted eating has been shown to help in the reduction of body fat and decrease in biomarkers such as glucose and cholesterol. Studies have shown a reduction of hunger and eating less overall. There have been animal and humans studies showing that a fasting diet can help reduce body fat, risk of disease and increase lifespan.
Multiple studies show that changing the timing of meals fights against diseases and obesity that are impacting quality and quantity of life. Counting calories does not work – we have seen multiple studies proving this. Instead, we should focus not on counting calories, but the hours in which we are actually eating.
Kristin Kirkpatrick, MS, R.D., is the manager of wellness nutrition services at the Cleveland Clinic Wellness Institute in Cleveland, Ohio, and the author of "Skinny Liver." Follow her on Twitter @KristinKirkpat. For more diet and fitness advice, sign up for our One Small Thing newsletter.