Intermittent fasting (IF) has gained popularity in recent years as a dietary approach with potential health benefits.


Many people are reliant on this weight management method. Here there is a definite window for eating and a fixed window for fasting.

The idea is to cut off eating for a long stretch (as per convenience) and then indulge in eating.

However, like any dietary regimen, intermittent fasting has both positive and negative effects on health.

While some individuals may experience positive outcomes, others may encounter adverse effects.

Here are five potential harmful effects of intermittent fasting:

1. Nutritional deficiencies​

Intermittent fasting restricts the time window for eating, which can make it challenging to consume an adequate amount of essential nutrients within a limited period. Depending on the fasting protocol followed, individuals may struggle to meet their daily requirements for vitamins, minerals, and other vital nutrients. Prolonged fasting periods without proper nutritional planning may lead to deficiencies in nutrients such as vitamins A, D, E, K, B vitamins, calcium, iron, and zinc. Additionally, inadequate intake of macronutrients like protein, carbohydrates, and fats can negatively impact overall health and wellbeing.

2. Ulcer​

Intermittent fasting may exacerbate symptoms of ulcers due to increased stomach acid production during fasting periods, potentially leading to discomfort, pain, and aggravation of ulcerative lesions. Skipping meals or prolonged fasting can further irritate the stomach lining, worsening ulcer symptoms and delaying healing. Individuals with ulcers should approach intermittent fasting cautiously and consult with a healthcare professional before implementing any fasting regimen. Proper hydration and consuming ulcer-friendly foods during eating windows are essential to mitigate potential adverse effects on stomach health.

3. Eating pattern disorder​

Intermittent fasting may trigger disordered eating patterns and behaviors, particularly in individuals prone to or currently experiencing eating disorders such as anorexia nervosa or bulimia nervosa. The strict rules and regulations surrounding fasting periods may exacerbate obsessive thoughts about food, weight, and body image. For some individuals, intermittent fasting can lead to a cycle of restriction and binge-eating episodes, as the fasting periods may trigger intense hunger and cravings. This cycle of restriction and overeating can contribute to feelings of guilt, shame, and loss of control, perpetuating a harmful relationship with food.

4. Diabetes​

Intermittent fasting itself doesn’t directly cause diabetes but may potentially contribute to its development or exacerbation if not managed properly. Prolonged fasting periods can lead to irregular eating patterns, resulting in overeating or consuming unhealthy foods during non-fasting periods, which can lead to weight gain and insulin resistance over time. Additionally, fasting without adequate hydration or nutrient intake may stress the body and impair glucose metabolism. Furthermore, inconsistent fasting patterns can disrupt hormonal balance and increase cortisol levels, which may further impact insulin sensitivity and glucose regulation. Overall, improper implementation of intermittent fasting may indirectly contribute to diabetes risk factors.

5. Hormonal imbalance​

Intermittent fasting can disrupt hormonal balance in the body, leading to adverse effects on metabolism, reproductive health, and overall wellbeing. Prolonged fasting periods or chronic calorie restriction may trigger hormonal changes that can affect thyroid function, cortisol levels, insulin sensitivity, and reproductive hormones. One of the primary concerns with intermittent fasting is its potential to increase cortisol levels, the body’s primary stress hormone. Elevated cortisol levels can contribute to inflammation, insulin resistance, and metabolic dysfunction, ultimately impairing overall health.