Intermittent Fasting (IF) has become a popular weight loss trend. This method revolves around dividing eating and fasting times during the day or week.
The two most common forms are fasting for 16 hours and eating within the remaining 8 hours (16:8), or eating normally for 5 days and cutting extremely low calories (500-600 calories) for 2 consecutive days (5:2).
Although IF can help improve metabolic health and reduce inflammation, it is not for everyone. Nutritionist Ana Reisdorf (Founder at GLP-1 Hub) warns that in some specific cases, fasting can have negative consequences.
For people entering middle age (from 40-50 years old onwards), the body tends to lose muscles naturally. Performing IF makes it more difficult to get enough protein each day. When there is a nutritional deficiency, the body loses muscles faster, reducing the rate of basic metabolism. In addition, fasting for too long can stimulate the production of cortisol – a stress hormone, leading to prolonged fatigue.
5 groups of subjects who should not apply intermittent fasting as recommended by Dr. Reisdorf:
1. Postmenopausal and menopausal women: During this period, hormones are changing strongly, fasting can worsen endocrine disorders.
2. People with diabetes (especially type 1): Fasting makes it difficult to control stable blood sugar.
3. Athletes or people with high exercise intensity: This group has very high nutritional and energy needs, fasting causes the body to lack "fuel" to recover and function.
4. People who are using weight loss support drugs (such as GLP-1): Combining drugs with IF can cause calorie and protein intake to drop too low, causing weakness.
5. People with a history of eating disorders: IF easily leads to extreme food psychology.
Many people, especially women, often do not realize they are overfed. Warning signs include: the body is always in a state of exhaustion, heavy hair loss, obvious muscle mass loss, or the weight loss process is completely stalled even though they are still fasting.
To minimize risks, experts recommend maintaining drinking 2-3 liters of water per day to support the kidneys and dilute minerals, preventing stones. At the same time, prioritize plant protein (such as lentils, nuts) instead of abusing animal protein; Increase natural citrate-rich foods (lemon, orange) and reduce salt.
If symptoms such as chronic rib pain, urinary bleeding, fever, or nausea appear, immediately stop fasting and see a doctor for a health check-up.
