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Diet Awareness Behavior Glossary

Myths About Intermittent Fasting

1 week, 5 days ago

1667  0
Posted on Jul 09, 2024, 4 p.m.

Researchers from the University of Illinois debunked four common myths about the safety of intermittent fasting in a new commentary published in Nature Reviews Endocrinology, basing their conclusions on clinical studies. 

Over recent decades, intermittent fasting has become an increasingly popular way to effectively lose weight without having to count calories, and a large body of evidence shows that it is safe. Despite the evidence, several myths have gained traction such as intermittent fasting can lead to a poor diet or loss of lean muscle mass, cause eating disorders, or decrease sex hormones. 

The researchers debunk these myths one by one

To begin, there are two types of intermittent fasting:

Alternate-day eating, in which people alternate between days of eating a very small number of calories and days of eating what they want. 

Time-restricted eating is when you eat what you want during a 4 to 10-hour window daily, then don't eat (fast) for the rest of the day. 

The researchers conclude both types are safe despite the popular myths.

Intermittent fasting does not lead to a poor diet: 

The researchers point to studies showing the intake of sugar, saturated fat, cholesterol, fiber, sodium, and caffeine do not change during fasting compared with before a fast. And the percentage of energy consumed in carbohydrates, protein, and fat doesn't change, either.

Intermittent fasting does not cause eating disorders: 

None of the studies show that fasting caused participants to develop an eating disorder. However, all the studies screened out participants who had a history of eating disorders, and the researchers say that those with a history of eating disorders should not try intermittent fasting. The researchers also urge pediatricians to be cautious when monitoring obese adolescents if they start fasting, because this group has a high risk of developing eating disorders.

Intermittent fasting does not cause excessive loss of lean muscle mass: 

The studies show that people lose the same amount of lean muscle mass whether they're losing weight by fasting or with a different diet. In both cases, resistance training and increased protein intake can counteract the loss of lean muscle.

Intermittent fasting does not affect sex hormones: 

Despite concerns about fertility and libido, neither estrogen, testosterone nor other related hormones are affected by fasting, the researchers said.

Based on personal opinion, not science

"I've been studying intermittent fasting for 20 years, and I'm constantly asked if the diets are safe," said lead author Krista Varady, professor of kinesiology and nutrition at UIC. "There is a lot of misinformation out there. However, those ideas are not based on science; they're just based on personal opinion."

As with anything you read on the internet, this article should not be construed as medical advice; please talk to your doctor or primary care provider before changing your wellness routine. This article is not intended to provide a medical diagnosis, recommendation, treatment, or endorsement. Additionally, it is not intended to malign any religion, ethnic group, club, organization, company, individual, or anyone or anything. These statements have not been evaluated by the Food and Drug Administration. 

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