The human body is surprisingly capable of enduring the effects of overeating, according to a new study just released by the University of Bath’s Centre for Nutrition, Exercise, and Metabolism. However, there’s a catch. Overeating will start to harm one’s health if it becomes a regular occurrence. Occasional overeating, on the other hand, does not appear to result in any immediate, negative health repercussions from a metabolic control perspective.
Everyone overeats from time to time, and overeating is even somewhat expected or encouraged on big holidays or events. Begging the question, what effects do these extended eating sessions have on our metabolisms? That’s what the team at UB set out to answer when they asked a group of young (ages 22-37 years old), healthy men to keep eating pizza long after they started to feel satisfied.
Incredibly, this experiment revealed that a young, healthy adult male is capable of eating twice as much pizza as his body needs without suffering from metabolic consequences. Put more technically, an adult male can double his usual caloric intake and still maintain a normal range of nutrients in his bloodstream.
This experiment only involved men. So further research will have to be done before the same can be said for a healthy, adult woman. More experiments are also needed to assess the effect of a single overeating episode on an overweight or obese individual. All that being said, these findings nonetheless provide compelling evidence that an occasional extra slice of pizza or bag of chips won’t wreak havoc on anyone’s metabolism.
“We all know the long-term risks of over-indulgence with food when it comes to obesity, type II diabetes, and cardiovascular disease, but we know much less about some of the immediate effects ‘all you can eat’ places on the body. Our findings show that the body actually copes remarkably well when faced with a massive and sudden calorie excess. Healthy humans can eat twice as much as ‘full’ and deal effectively with this huge initial energy surplus,” explains lead researcher Aaron Hengist in a university release.
On average, overeating study participants ingested 3,000 calories (about one and a half pizzas). Although, the study’s authors also noted that a few men were able to eat two and a half pizzas in one sitting. Still, even just the average of 3,000 calories in one meal is far more than most people are supposed to ingest all day. In summation, subjects ate a whole lot of pizza.
Immediately after finishing their extended meal, participants’ blood sugar levels were no different than what they would have been after a normal meal. However, insulin levels in their blood were about 50% higher than usual, but that’s to be expected (insulin is used to control blood sugar levels).
Furthermore, participants’ blood lipid (triglycerides, non-esterified fatty acids) levels were only somewhat higher than normal. This is especially noteworthy because it contradicts previous research that had concluded blood lipids rise proportionately with fat consumption. Subjects had more than doubled their usual fat intake.
One variety of hormones (GLP-1 and peptide YY) were released in larger amounts in response to overeating. These hormones activate insulin secretion and feelings of fullness.
“We know that people often eat beyond their needs, which is why so many of us struggle to manage our body weight. It is therefore surprising that no previous research had measured the maximal capacity for eating at a single meal in order to understand how the human body responds to that challenge,” comments Professor James Betts, a study co-author.
The research team also followed up with the study’s participants a few hours after overeating to see how they were feeling. As one would probably expect, they were feeling particularly lethargic, full, and had no desire whatsoever to eat anything else, even dessert foods.
“This study reveals that humans are capable of eating twice as much food as is needed to make us feel ‘full’, but that our bodies are well adapted to an excessive delivery of dietary nutrients at one huge meal. Specifically, those tested in this study were able to efficiently use or store the nutrients they ingested during the pizza-eating challenge, such that the levels of sugar and fats in their blood were not much higher than when they ate half as much food,” Professor Betts adds.
“The main problem with overeating is that it adds more stored energy to our bodies (in the form of fat), which can culminate in obesity if you overeat day after day. However, this study shows that if an otherwise healthy person overindulges occasionally, for example eating a large buffet meal or Christmas lunch, then there are no immediate negative consequences in terms of losing metabolic control,” he concludes.
The full study can be found here, published in The British Journal of Nutrition.