For people, mealtime is all the time

The new study deployed a smartphone app specifically designed for the research.

The participants ate and drank almost all day, researchers found. Fewer than 10 percent of participants went for more than 12 hours without eating.

“Our research on the benefits of time-restricted feeding in mice elicited mixed feedback”, Satchidananda Panda, an associate professor in the Salk Institute’s Regulatory Biology Laboratory and graduate student Shubhroz Gill said in a statement.

LiveScience. “For example, [a] cream-cheese-Cheeto sandwich [or] rice crispy with spicy trail mix. Most people also assumed that they had been confining their eating routine to a 10- to 12-hour window”. [9 Snack Foods: Healthy or Not?]. People also ate throughout the entire day.

The study is published in the journal Cell Metabolism.

Lest you think “grazing” refers to the “several small meals” dietary pattern that many weigh loss programs recommend, Panda found that more “eating hours” meant more calories. The same app was used to track their meals, calories and what time they ate. The app also captured metadata, such as where the food was eaten, and a timestamp. Panda and his team wanted to know about every single french fry stolen from someone else’s plate. People would send pictures of anything they ate or drank, from a whole bottle of water to a few bites of a cookie, for analysis.

The researchers worked to make their app “ridiculously simple” to use, and employed push notifications to remind people to keep snapping photos. The average amount of time between snacking and/or meals was about three hours, with the upper 25 percent eating about every six hours and the lower 25 percent eating every 1.5 hours. And more than a third of participants’ average daily calories, the research revealed, were consumed after 6 p.m. The photos were timestamped so the researchers knew when they were eating, as well as what and how much. Many skip breakfast, have a light lunch, then find themselves hungry and exhausted in the afternoon and seeking a pick-me-up from the vending machine, only to get home from work ravenous and wanting to eat anything and everything with no energy to exercise.

After 16 weeks, each lost an average of 3.5 percent excess body weight and reported feeling more energetic and had better sleep. No one was asked to modify his or her normal eating habits in any way.

One reason for this calorie cutting may have been that people tend to stick to certain consumption patterns, Panda said.

“The study is about developing methods and offers some preliminary insight into what and when people eat”, Panda says. For example, an earlier window might lead to drinking less alcohol. They wished to test and answer the question whether restricting the period of eating could be efficient in weight loss. They then spend the night snacking before bed. And diet and circadian rhythm are tightly linked.

Information about the locations of food consumption was revealed through backgrounds of the images.

“We have evolved to eat during the daytime”, he said.

A follow-up experiment tracked eight participants who were classified as obese and who had a habit of consuming food for periods stretching beyond 14 hours each day.

Researchers at the conference were also interested in replicating the study in Europe, India and Japan, he said.

“Lifestyle is a combination of what we do and when we do it”, Panda explained.

In prior research, when animals restrict their eating hours, they lose weight. “Accordingly, we all have developed a timing system or circadian clock to turn on and off thousands of genes at the right time of the day to tune our physiology and metabolism”.