Foods like vegetables, fruits and nuts, the more you eat, the faster you lose weight. Those who claim that negative calorie foods work are backed up by the fact that these foods have a lot of fiber, which doesn't provide energy to our bodies, but the body uses some of that energy to break it down ......
At first glance it sounds kind of plausible, but is it really?
Image source: /biaoqing/detail/id/572898.html
They're not just smart, they have to come up with experimental results
There have been a lot of rumor mills on the Internet, and they've all been analyzed from theory. Dialectical materialism holds that practice is the only test of truth. Researchers from the University of Alabama, Tuscaloosa, have done just that, and they're not going to pull their punches, they're just going to do an experiment to dispel the rumors.
How do they do the experiment?
The experimental method used by the scientists was to determine the metabolizable energy of a particular food using the whole-harvest method.
The metabolites produced during an animal's life activities are excreted in feces and urine, in addition to body heat, gases, trace secretions, and epidermal shedding. Therefore, the body heat produced by the animal is measured under closed conditions, and the collection of urine and feces can be used to roughly calculate the amount of heat produced by that food, and the heat that is ultimately digested is known as metabolizable energy.
Metabolizable Energy Calculation Formula (Image Source: Laboratory Tutorial on Animal Nutrition)
Among the rumored negative calorie foods, celery is the most famous. Because most people have the impression that celery has a rough texture, they feel that celery is rich in fiber, which also burns calories ......
Online rumors of negative calorie food: celery (Image source: Screenshot of a search site)
The Pine Lizard Experiment concluded that celery is not a negative
Well, since everyone thinks so, the researchers satisfied everyone by choosing celery as the material for the experiment, and the subjects were nine pine lion lizards.
Pine lizards (Photo credit: Wikipedia)
Researchers chose this seemingly unfamiliar reptile because they're naturally omnivorous, possessing a digestive system similar to that of an omnivorous mammal, and because they're docile and willing to eat celery, making them easy to study in the lab.
Since they are doing digestive experiments, they have to be prepped first. First, the lizards were kept in cages and fasted for 10 days to make sure they didn't produce feces associated with other foods. As if that weren't enough, of course, the researchers also gave them enemas, which now cleared up any residual feces or urine that might have interfered.
Once these pre-treatments were done, the researchers took the lizards to a metabolic cage for testing. The metabolic cage, which is small enough to fit a single lizard, is used to collect the urine and feces that are naturally excreted by the animal so that its overall metabolism can be calculated. The urine and feces will be collected separately, and the calories from the urine and feces can be calculated separately, which can reduce the error of calculation.
Desert forest rat in a metabolic cage (Photo credit: www.eurekalert.org)
The confined space controls the flow of air in and out so that the researchers can accurately measure how much energy was consumed by the pine marten lizard by eating the meal of celery at a given time.
The pine lion lizards began eating as soon as they entered the metabolic cage, and each lizard was able to consume 7.83 ± 0.23 kilojoules of calories of celery. Over the next three days, the researchers then began collecting their urine and feces daily, where the fecal samples would be dried and then weighed.
Next, these collected samples were put into a pop-up calorimeter to accurately calculate the calories from the feces and urine produced by the lizards. Finally, when they were done pooping, they were given an enema to make sure there was no residual celery still undigested in the lizards.
After collecting the data from the experiment, the researchers then began to calculate whether the celery meal had produced negative calories or not (the following are the figures for the average lizard):
(Image source: Ref. 1)
From the data table, we can see that 2.29 kilojoules are the calories produced by the feces, 1.06 kilojoules are the calories produced by the urine, 2.53 kilojoules are the calories produced by digestion, 1.89 kilojoules are the calories produced by digestion, and 2.53 kilojoules are the calories produced by the lizards. calories produced, and 1.89 kJ for net energy ingested, resulting in a final calculated metabolizable energy of 23.4% for celery.
In short, this result shows that celery is not a negative-calorie food. 7.83 kJ of celery ended up being consumed by the pine lion lizard for 1.89 kJ. Although this was not an experiment with humans as subjects, and this calculation does not apply to humans, the researchers say, "If humans ate this celery, they would only consume a higher amount of calories."
Eat enough celery to lose weight? It's possible but not realistic
Of course, it's possible to lose weight if you plan to eat all that celery all the time.
Despite the fact that these pinto lizards brought in calories with every bite of celery they ate, their total calorie intake over the 3 days was negative. This is because over the course of 3 days, the lizards' basal metabolism (the minimum energy metabolism, called basal metabolism (BM), that is necessary to maintain basic life activities such as heartbeat and respiration) ends up exceeding the total number of calories from the celery intake by at least 6 kilojoules of calorie loss.
If you eat only celery for 3 days, a pine lion lizard loses 6 kJ of calories, while a female human loses 4,023 kJ of calories (image source: Ref. 1)
That is, if you plan to live on only a small plate of celery a day, odds are you'll starve to death, but the total amount of calories ingested will still satisfy your body's daily caloric needs if you eat enough of it, provided that you can eat that much celery. Because of this, pine lizards normally eat more than just celery, but also higher-calorie foods like kale, mustard greens, carrots, squash, and protein-rich crickets.
At this point, we can say that the ultimate conclusion of this experiment is that celery is not a negative-calorie food.
Here's another tidbit: the son of the scientist who did the experiment had offered to do human experiments on negative calories, and wanted to volunteer for the experiment. But when he heard that his feces would need to be collected and dried, he declined.
References:
1. Buddemeyer, K. M., Alexander, A. E., & Secor, S. M. (2019). Negative calorie foods: an empirical examination of what is fact or fiction. doi:10.1101/586958
2, "Laboratory Tutorial on Animal Nutrition" by Yuan Tassel
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