Intermittent fasting (IF) is increasingly popular for weight loss, but it’s not suitable for everyone. Here’s a closer look at who should steer clear of this eating pattern and why.
Intermittent fasting (IF) has become a favored method for weight loss among many individuals. It entails cycling between periods of eating and fasting, aiming for weight loss, improved metabolic health, and reduced inflammation. Common approaches include fasting for 16 hours while eating within an eight-hour window or consuming a typical diet for five days and then limiting calorie intake to around 500-600 for two consecutive days.
Despite its potential benefits, there are risks associated with IF. Pregnant individuals and those with specific chronic conditions should avoid intermittent fasting. To delve deeper into this method, we consulted with Ana Reisdorf, MS, RD, a Registered Dietitian and Founder of GLP-1 Hub, who explains why she advises certain clients to keep away from fasting altogether.
Individuals in their 40s, 50s, and beyond may find that IF complicates meeting their daily protein requirements, potentially leading to increased muscle loss. This is particularly concerning as muscle mass naturally declines with age. Furthermore, fasting may lower metabolic rates and elevate cortisol levels (the stress hormone) over time.
Who Shouldn’t Intermittent Fast
While IF can yield positive results for some and is supported by a variety of research, it is not universally suitable for everyone.
“For individuals experiencing hormonal changes (like during menopause or perimenopause), high stress levels, or who are on GLP-1 medications, fasting can lead to low calorie and protein intake, which increases fatigue, muscle loss, or hormonal dysregulation,” explains Reisdorf.
Who’s More Likely To Experience Negative Effects
Reisdorf shares that individuals in menopause and perimenopause, those with diabetes (especially type-1), athletes with higher nutritional requirements, and individuals on GLP-1 medication are most likely to face adverse effects from IF.
“These populations have increased protein needs, face hormonal imbalances, and simply cannot afford to underfuel themselves,” Reisdorf clarifies.
How Common It Is To Experience Setbacks With IF
Experiencing setbacks with IF is relatively common, especially among women who are not already consuming adequate calories or are under considerable stress.
“Many people might not realize they are undereating due to IF until they experience fatigue, hair loss, muscle decline, or a plateau in weight loss,” Reisdorf notes.
Mental and Behavioral Challenges You May Face When Fasting
IF often triggers obsessive thoughts about food, leading to rebound overeating and “black and white thinking” around dietary habits.
“For some individuals, IF amplifies an all-or-nothing mindset,” Reisdorf observes.
If you want to learn more about the benefits of GLP-1 medications, check out 5 Surprising Health Benefits of GLP-1 Drugs That Have Nothing to Do with Weight Loss.
Alexa Mellardo
Alexa is a freelance writer, editor, and content strategist based in Greenwich, CT. With over 11 years of experience, she covers various topics, including wellness, fitness, food, travel, lifestyle, and home.
