New research from the University of Georgia has found that a specific regimen of time-restricted eating may prevent Type 2 diabetes (T2D) and obesity. A form of intermittent fasting, time-restricted eating is characterized by having regular but fewer meals, and cutting out late night snacking, while not eating for 12 to 14 hours, with much of that time often achieved overnight.
The University of Georgia team conducted a comprehensive review of published, peer-reviewed studies and found a connection between the number of meals consumed per day with obesity and the development of Type 2 diabetes.
According to the research, published in the journal Nutrients, the current non-third-world eating model of three meals per day plus snacks, has been born out of around the clock access to food due to urbanization and eating behavior that has changed as a result. But human history hasn’t always included such frequent eating. “For example, ancient Romans ate one meal each day with two smaller snacks and believed more than one meal a day was unhealthy. Moreover, preindustrial and Paleolithic societies periodically underwent severe shortages and were forced to eat less often,” the study authors wrote.
“What we’ve been taught for many decades is that we should eat three meals a day plus snacking in between,” said Krzysztof Czaja, associate professor of biomedical sciences in UGA’s College of Veterinary Medicine. “Unfortunately, this appears to be one of the causes of obesity.”
The current standard of eating three meals per day, plus snacks in between prevents insulin levels from going down during the day. That, combined with the number of calories and the amount of sugar an average American consumes during the day can overload insulin receptors, leading to insulin resistance and the development of T2D.
As Czaja noted, this patterns makes it difficult for people to lose body fat. “We are not giving our bodies a chance to use it. Having fewer meals a day will allow these fat deposits to be used as an energy source rather than the sugar we keep consuming,” he noted.
But time-restricted eating can help the body relax and lower insulin and glucose levels. This helps the body improve insulin resistance, brain health, and glycemic control. Further, people practicing this method of eating can reduce daily calorie intake by about 550 calories a day with the need to be fastidious about calories counting as a method to lose weight.
The team found other benefits to time-restricted eating such as a positive impact on a person’s gut microbiome which can help prevent inflammation and metabolic disorders, and these eating patterns may also help regulate the hormones responsible for appetite regulation and energy levels.
But the researchers noted that too much of a good thing doesn’t always confer benefits. While time-restricted eating shows evidence of improving health, extended periods of fasting provide few benefits.
In addition to the preventative effects for T2D, intermittent fasting also plays a role in reducing obesity and the prevention of metabolic disorders. Obesity can lead to a number of health disorders including T2D, heart disease, and has also been shown to play a role in the development of certain forms of cancer.
With more than four-in-ten people in the U.S. classified as clinically obese, and 10% qualifying as severely obese, finding new methods of treating this high prevalence is paramount.
“Obesity is an epidemic right now, especially in the United States,” Czaja said. “It is a preventable disease. When we started looking at the research, we found that ancient humans didn’t eat every day. That means our body evolved not needing food every day.”
The bottom line, he said, is that the gut-brain signaling of modern humans is not designed for three meals per day plus snacks. The researchers warn that dietary approaches to help prevent Type 2 diabetes and obesity is not one-size-fits all. Some people may only need one meal per day, while athletes may require a higher caloric intake to maintain health.
However, Czaja said that the literature review provided very clear evidence that fewer meals of high-quality food provides a good, broad guideline for people at risk of developing T2D.
