When you think about the problems of ultra low-calorie diets, you probably think of two things: what it does to your metabolism and how it causes yo-yoing weight. You might worry about how it will impact your health long-term or about the fact that you are more likely to lose muscle than fat. But, new research shows you should have another concern.
Following a very low-calorie diet negatively changes the microbiome. Researchers found that extreme dieting increased bacteria that causes antibiotic-induced diarrhea and colitis. The bacteria can reduce the nutrients the gut absorbs.
Under the care of doctors, people in the study had just 800 calories a day consumed as a liquid. The study lasted 16 weeks. While the group lost weight, they also lost gut diversity. And, while some types of bacteria increased, overall, people had fewer bacteria. You want a lot of bacteria and a lot of variety in your gut. Over the 16 weeks, the participants didn’t have any health problems. But, the bacteria is associated with gut illnesses, and it’s hard to tell what the long-term impact might be.
The bacteria consumed more sugar in the gut than typically and left the people hungrier with less for their bodies to absorb. That may explain the weight loss. The study’s first author, Dr. Reiner Jumpertz von Schwartzenberg, said, “One might say we observed the development of a ‘hungry microbiome.’”
The doctors stressed that the rise of the bacteria shouldn’t be treated as a method for weight loss. While the weight loss may be appealing, the scientists didn’t learn the long-term outcomes from the study. It was only 16 weeks long. More research is need, with follow-ups, to know what happens after time. The study was relatively small; only 80 women were studied. We need a larger group to ensure the results are the same and see if people become ill.
The bottom line is that the biodiversity was lost, and the potentially harmful bacteria rose. While we don’t know the larger ramifications, we know that a flourishing gut is needed for robust health and good digestive well-being. We always say that the best diet is one with tons of variety, and you can enjoy practically any food in moderation. While extreme diets are enticing for their promise of fast results, it’s better to work toward your goal steadily than to harm your body for a short-term win.