ATHENS, Ga. — Intermittent fasting has turned into something of a trendy approach to weight loss in recent years, with many celebrities endorsing the eating strategy. While many remain very skeptical about the notion of skipping meals entirely to help lose weight, researchers from the University of Georgia suggest that Hollywood may actually be on to something this time.
Scientists report that a specific variety of restricted eating may indeed reduce one’s chance of developing Type 2 diabetes, as well as improve overall health. Referred to as time-restricted eating, this type of fasting entails eating regular but fewer meals, cutting out late-night snacks entirely, and not eating for a total of 12 to 14 hours daily (often overnight).
Study authors conducted a comprehensive review of previously published, peer-reviewed studies, ultimately uncovering a connection between number of meals and obesity and Type 2 diabetes.
“What we’ve been taught for many decades is that we should eat three meals a day plus snacking in between,” says Krzysztof Czaja, an associate professor of biomedical sciences in UGA’s College of Veterinary Medicine, in a university release. “Unfortunately, this appears to be one of the causes of obesity.”
Countless people follow a typical three-meals-and-some-snacks approach to daily eating, but study authors explain this approach stops insulin levels from going down during the day. This effect, combined with the high average level of calories and sugars consumed by Americans, can potentially end up overloading the body’s insulin receptors – eventually leading to both insulin resistance and often Type 2 diabetes.
“That’s why it’s so hard to lose body fat,” Prof. Czaja adds. “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.”
Researchers uncovered that time-restricted eating allows the body to relax and lower insulin and glucose levels, in turn potentially improving insulin resistance, brain health, and glycemic control. This approach can also lower calorie intake by roughly 550 calories daily – all without the added stress of calorie counting.
Earlier work has shown that sleep disruptions to both sleep and meal habits can spark changes in both the type and amount of bacteria and other microorganisms present in one’s digestive tract. Fasting, though, may positively change the gut microbiome, potentially staving off inflammation as well as a variety of other metabolic disorders. Moreover, this study also indicates that time-restricted eating can help regulate hormones responsible for both appetite regulation and energy levels.
The study posits that regular meal schedules, as well as eating breakfast and decreasing meals and snacks, can help protect against obesity and Type 2 diabetes. Of course, not all breakfasts are created equal; always try to aim for healthier fats and proteins like eggs, all while avoiding sugar-filled breakfast options like cereals and pastries.
While time-restricted eating certainly appeared to improve health during this study, researchers also stress that other varieties of restricted eating techniques, such as fasting for days on end, provided few benefits at all.
Estimates show that over four in 10 Americans are clinically obese, which means their weight is much higher than what is seen as a healthy range relative to their height. According to the CDC, nearly 10 percent are severely obese. It’s well documented that obesity can lead to numerous serious health issues and complications including heart disease, Type 2 diabetes, and even some cancers.
“Obesity is an epidemic right now, especially in the United States,” Prof. Czaja comments. “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 typical modern approach to daily eating of three meals plus snacks became popular decades ago, and it’s hard to break old habits – both individually and on a population level.
“But our gut-brain signaling is not designed for this type of eating,” Prof. Czaja says.
All in all, researchers caution that eating is not a one-size-fits-all formula; different people need different diets. Smaller, less active people likely need fewer calories on average than taller athletes, for instance. So for some, one meal of nutrient-rich food might be enough while others may need more. One finding, however, appears quite clear in light of this review: fewer meals consisting of high-quality food is a strong recommendation for individuals at risk of developing Type 2 diabetes and obesity.
“Also definitely avoid late-night eating,” Prof Czaja concludes. “Our midnight snacks spike insulin, so instead of us going into a resting state when we sleep, our GI is working on digestion. That’s why we wake up in the morning tired—because we don’t get enough resting sleep.”
The study is published in the journal Nutrients.