Intermittent Fasting: Benefits, Risks, and How to Practice It Safely

Intermittent fasting has become increasingly popular as a strategy for weight loss , improving metabolic health , and overall well-being . Unlike traditional diets, this practice doesn't dictate which foods should be consumed, as traditional diets do, but rather when to eat. It's based on alternating cycles of fasting and eating in specific windows, which can vary between 12 hours, 16 hours, 18 hours, or even 24 hours without calorie intake. Is intermittent fasting safe for everyone? What are its real benefits, and what are the risks that require attention?

Intermittent fasting consists of alternating periods of abstinence/restricted energy intake (calories) with specific eating windows, which can vary between 12, 16, 18, or even 24 hours without eating. There are several protocols, such as alternate-day fasting, time-restricted eating (eating meals within a 6- to 8-hour window), or the 5:2 method (eating normally for 5 days, fasting/restricted dieting for the other 2 days). It is very important that this practice be supervised by a professional in the field, such as doctors or nutritionists.

Intermittent fasting can bring several health benefits when well guided and adapted to the individual profile.

• Studies show significant weight loss, especially in the short term, with a reduction in waist circumference and body fat. Remember that if left unchecked, the individual may experience changes and end up losing muscle mass in the process!

• Fasting protocols can help reduce insulin resistance, improve blood glucose levels, and decrease inflammatory markers related to cardiometabolic risk.

• Decreases in total cholesterol, LDL (bad cholesterol), blood pressure and inflammation markers were observed, strengthening metabolic health.

• Reports include increased energy, reduced oxidative stress, increased cellular autophagy (benefits longevity and cell renewal), and some studies show improved mood and cognitive function.

Despite the benefits, intermittent fasting requires caution.

• Hypoglycemia, fatigue, binge eating, and discomfort such as bad breath, dizziness, and constipation may occur, especially when done without professional guidance or for a prolonged period.

• It is not recommended for everyone: pregnant women, the elderly, people with type 1 diabetes, individuals with eating disorders, patients regularly taking medications, and breastfeeding women require special attention and should often avoid the protocol.

• Nutritional deficiencies can arise if meals are not balanced in essential micronutrients and macronutrients.

To ensure the best results and minimize risks, follow some crucial recommendations:

• Most common models: 12h, 16h, 18h and 24h of fasting; start with shorter periods and adjust as your body adapts.

• Prioritize constant hydration during fasting and maintain high-quality nutrition during your eating windows: focus on natural foods, lean protein sources, fiber, healthy fats, and essential micronutrients.

• Always seek guidance from a nutrition professional before starting the protocol. An individual assessment takes into account your health history, goals, and adaptations, ensuring safety and optimal results.

Intermittent fasting can be a powerful tool for weight loss, metabolic improvement, and health promotion, as long as it's implemented with professional supervision and healthy dietary choices. It's not a one-size-fits-all solution: each person should evaluate the risks and benefits with the help of a nutritionist or doctor.