Research suggests that there is an optimal time to eat during the day.
According to two studies published in Cell Metabolism Tuesday, eating early can help with weight loss.
The first study showed that people who ate later in the day were more hungry than those who ate earlier in the day. Study participants also found that they ate later than usual and had a slower metabolism. Also, their fat tissue was more likely to store calories if they ate later than those who ate earlier. The study shows that obesity can be increased by eating later.
A second study was done with firefighters and found that eating within a 10-hour time frame reduced “bad cholesterol” particles, suggesting a possible reduction in heart disease risk factors. The eating window improved blood sugar and blood pressure among firefighters who have underlying conditions like diabetes, high blood cholesterol, and high blood pressure.
Courtney Peterson, an associate professor of nutritional sciences at the University of Alabama at Birmingham, said that these studies add to the evidence of optimal times to eat. She wasn’t part of either study.
“You have an internal biological clock that helps you do different things at different times. Peterson stated that the best time to increase metabolism is mid-to-late morning.
Research has shown that circadian rhythms, the body’s internal clock which regulates
sleep and wake cycles, can have an impact on people’s appetites, metabolism, and blood sugar levels.
Satchidananda Pande, co-author of the firefighter study, and professor at Salk Institute stated that a 10-hour window is a “sweet spot” as the stricter restrictions associated with many intermittent fasting diets are difficult to keep.
Panda stated that a benefit can be seen if people think for six to eight hours. However, it is not something people will stick with for long.
Late eating could lead to weight gain
The first study involved 16 overweight or obese people. Two different eating habits were tested for each day. The first was that some participants ate an hour after their normal wake-up time while others waited until five hours after they woke up to eat. The two groups then switched their schedules at a later time.
According to Frank Scheer (the senior author of the study and director of the Medical Chronobiology Program, Brigham and Women’s Hospital), the meals that they all ate were identical and had the same amount of nutrients and calories.
Researchers measured hormone levels in participants and found that late dining decreased leptin levels by an average of 16%. This hormone helps people feel full. The likelihood that participants felt hungry doubled when they ate late (people self-reported their hunger levels at 18 points throughout the day).
The researchers also found that late-eaters had a greater desire for starchy foods and salty food, along with meat, dairy, and vegetables. Scheer suggested that this could be because people are more hungry for energy-dense foods.
The study also showed that late-eating habits are associated with changes in fat tissue. This suggests an increase in the likelihood of fat cell growth and decreased fat burning.
The results also showed that late-eaters consumed 60 fewer calories per day than early-eaters, but Peterson stated that this was equivalent to eating one extra half apple each day so it is not that significant of a difference.
Peterson stated that even though a separate study last month found that eating large breakfasts and light meals did not increase calories, the results of the two studies were different.
Your body processes calories differently if you eat later in the day. It tips the scales in favor of fat gain and weight gain,” Peterson stated. He also said that “from this study, we can get quite clear recommendations that people should not skip breakfast.”
Scheer stated that more research is necessary before Scheer can make any recommendations.
The risk of developing heart disease could be reduced by allowing a 10-hour window for eating
The second study involved 137 firefighters from San Diego, California who followed a Mediterranean diet that included fruit, vegetables, and olive oil for 12 consecutive weeks. Seventy firefighters consumed their meals in a 10-hour time frame, while the rest ate for more than 13 hours.
Researchers tracked the blood sugar levels of firefighters who logged their meals using an app. The majority of participants in the 10-hour study ate between 8 and 9 a.m., 6 or 7 p.m., although they did occasionally eat outside the window for an 11- or 12-hour period.
Peterson stated that time-restricted eating had “favorable results” among healthy firefighters. This should lead to less plaque buildup in the arteries and less heart disease. This group of firefighters also reported a better quality of life.
Time-restricted eating led to a drop in blood pressure and sugar levels among firefighters who had pre-existing heart disease risk factors.
Peterson stated that while there have been many hints that time-restricted consumption can improve blood sugar control and blood tension, this study is the first to test this on a large scale with people who work shifts.
Panda stated that past research on animals has shown that when they fast, the organs take some time to digest food and can then use their energy for repair.
Panda stated that fasting may also help to break down toxins. Peterson also said that fasting can help lower blood pressure by allowing the body to eliminate sodium.
She stated that she would not be surprised to see national recommendations regarding meal times and eating windows in the United States shortly.