Is intermittent fasting healthy? Maybe not. New research suggests that intermittent fasting, while a popular diet trend, may lead to dangerous eating behaviors in some young people.
Experts say that fasting may reinforce distorted self-image or compulsive behaviors in vulnerable individuals.
They also say that more research is needed to confirm if this dietary approach is actually a healthy way to control weight.
Intermittent fasting (IF) has been popularized for its supposed health benefits, which are backed by some research.
But new findings published in Eating Behaviors from the University of Toronto have linked intermittent fasting with disordered eating and potentially dangerous, compulsive behaviors.
What is intermittent fasting?
According to Dr. Jessica Folek, director of bariatric surgery at Long Island Jewish Forest Hills, part of Northwell Health in New York:
• IF is an eating regimen characterized by cycles of fasting and time-restricted eating.
• Examples of IF include 16/8, where you fast for 16 hours and eat during an 8-hour window, 14/10, which means fasting for 14 hours and eating between a 10-hour window, and other variations.
• IF has become very popular, and some studies have shown IF to be effective for weight loss.
• However, there is a lack of long-term studies and studies with conflicting results.
Is Intermittent fasting healthy?
A new study suggests that this eating regimen may cause eating disorders in some dieters, especially teens and young adults.
• The University of Toronto study analyzed data from nearly 3,000 adolescents and young adults originally collected by the Canadian Study of Adolescent Health Behaviors.
• Researchers discovered an association between IF and all disordered eating behaviors in women.
• That includes binge-eating, as well as compensatory behaviors like vomiting and compulsive exercise,” lead study author Kyle T. Ganson, PhD, MSW, assistant professor at the University of Toronto.
• For men, those who tried the diet routine were also more likely to report compulsive exercise.
• Ganson wasn’t surprised by the findings: “Given that we know that dietary restraint/restriction is a major risk factor for eating disorders, we hypothesized that IF, which is in many ways a more regimented practice of dietary restraint/restriction, would also be.”
Intermittent fasting linked to other dangerous behaviors
Ganson and team found the prevalence of intermittent fasting behaviors among adolescents and young adults was significant:
• Findings indicate that 38 percent of men, 47 percent of women, and a little over half of gender non-conforming or transgender individuals reported practicing IF in the past 12 months.
• Participants also reported fasting for an average of 100 days in the past 12 months.
• Additionally, it was concerning that IF was associated with many dangerous behaviors among young women, including compulsive exercise, laxative use, and vomiting.
Adolescents and young adults at increased risk
Dr. Timothy B. Sullivan, chair of psychiatry and behavioral sciences at Staten Island University Hospital in New York, told Healthline that fasting could produce a temporary state of pleasure or relief from distress.
“Similar to self-harming behavior, fasting may, in vulnerable individuals, be reinforced via reward pathways in the brain because the behavior alleviates anxiety or other unpleasant moods,” he said.
Sullivan added that fasting behavior might reinforce a distorted self-image or other “compulsive thoughts and behaviors” in those who feel they must lose weight to achieve social acceptance.
He pointed out that young people are already at increased risk of developing an eating disorder. Studies show that adolescents and young adults, as a group, are at increased risk of eating disorders,” Sullivan said.
“Women, for reasons that are not completely understood, are at increased risk relative to men, and transgendered persons are at especially increased risk.”
Is IF a healthy way to lose weight?
Folek said some studies show IF has benefits that include “ameliorating gut hormone levels, specifically lowering insulin levels, which decreases our risk for insulin resistance and diabetes, decreased markers for inflammation, and decreased visceral fat.
She added that more rigorous studies are needed to validate these results, and recent research didn’t show the benefits of using IF.
“A recent randomized controlled trial did not demonstrate superior weight loss in comparison to traditional calorie restriction diets,” she confirmed.
That study demonstrated a concerning, significant decrease in muscle mass compared to traditional diets. Typically, about 20 to 30% of weight lost is lean body mass. This is concerning as this could significantly decrease one’s metabolic rate, which also has been shown to result in weight regain down the road.
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