1. Aoun, Antoine MD, PhD
  2. Ghanem, Charbel MS
  3. Hamod, Natacha MS
  4. Sawaya, Sabine MS


Intermittent fasting (IF) diets have recently gained popularity as a weight loss and antiaging method that attracts celebrity endorsements and public interest. Despite the growing use of IF, the debate over its safety and efficacy is still ongoing. Defined IF regimens include 5 different types: alternate-day fasting, periodic fasting, time-restricted feeding, less clearly defined IF (fast mimicking diet, juice fasting), and religious fasts. Our literature review highlights the effect of IF essentially on body weight and cardiometabolic risk factors. Intermittent fasting may be effective for weight loss and may improve cardiovascular and metabolic health, although the long-term sustainability of these effects has not been studied. While data on the safety of IF are sparse, the most frequent adverse effects (hunger, irritability, and impaired cognition) may dissipate within a month of the fasting period. Intermittent fasting is not recommended for pregnant or lactating women, children or adolescents during maturation, the elderly or underweight people, and individuals vulnerable to eating disorders.