Intermittent fasting (IF) has become one of the most popular fitness trends for weight loss and metabolic health. Unlike typical diets that focus on what to eat, intermittent fasting emphasizes when to eat — limiting meals to specific time windows. While many swear by its benefits, health experts caution that this approach isn’t universally safe or effective.

What Is Intermittent Fasting?

Intermittent fasting involves scheduled periods of eating and fasting. The most common methods include:

• 16/8 Method: Fast for 16 hours, eat within an 8-hour window.

• 5:2 Diet: Eat normally for 5 days, restrict calories (about 500–600) for 2 non-consecutive days.

• 24-Hour Fasting: Abstain from food for a full 24 hours once or twice a week.

The method aims to shift the body into fat-burning mode, improving insulin sensitivity, promoting cell repair, and supporting overall metabolism.

Why Intermittent Fasting Isn’t for Everyone

Despite its popularity, intermittent fasting can have adverse effects, particularly for certain groups. According to Dr. Ananya Gupta, former specialist in Gastroenterology at AIIMS New Delhi, this diet can lead to serious health issues for some people, including malnutrition, fatigue, and blood sugar imbalance.

Here’s who should avoid intermittent fasting:

1. Pregnant and Breastfeeding Women

Their bodies require consistent nutrients and energy. Fasting can reduce essential vitamin and mineral intake, affecting both mother and baby.

2. Diabetics (Especially on Insulin)

Fasting can cause dangerous drops in blood sugar. Diabetics who are on medication or insulin therapy are at particular risk.

3. Thyroid, Kidney, or Hormonal Disorders

People with thyroid imbalances, kidney issues, or hormonal fluctuations need stable eating routines. Fasting may worsen these conditions.

4. Children and Teenagers (10–15 Years)

Their bodies are still developing, and restrictive diets can interfere with physical and mental growth.

5. Those With Eating Disorders

People struggling with anorexia, bulimia, or binge eating may find that IF triggers harmful eating behaviors or worsens mental health.

6. Individuals with Weak Immunity or Overtraining

If your immune system is compromised or you're engaged in intense workouts, fasting can lead to weakness, fatigue, or reduced performance.

If You Still Want to Try IF: Do It Safely

If you’re healthy and considering intermittent fasting, here are some important tips:

• Consult a doctor or dietitian before starting.

• Stay hydrated throughout your fasting period.

• Break your fast with healthy, balanced meals (avoid junk or excessive carbs).

• Don’t overeat after fasting; it can reverse potential benefits.

• Listen to your body — fatigue, dizziness, irritability, or weakness are signs to pause or stop.

• Avoid intense exercise while fasting, especially in the beginning.

• Skip IF if you're unwell or on medication.