ABSTRACT Objective To analyze quantitatively the diets available on blogs and websites. Methods The following 15 diets were analyzed: low-carb diet, gluten-free diet and intermittent fasting diet using the Virtual Nutri software program. The nutrients analyzed were as follows: carbohydrates, fibers, proteins, lipids, iodine, sodium, calcium, magnesium, iron, zinc, manganese, phosphorus, selenium, vitamins A, C, B6, B12, D, niacin, and folate. The nutrient values were compared with the Dietary Reference Intake recommendation for adults between the ages of 19-50 years. The macronutrient adequacy percentage was based on a 2000-kcal diet for a healthy life, as recommended by the World Health Organization. Results It was observed that most of the composition of macro and micronutrients was lower than the one established by the World Health Organization and the Dietary Reference Intake recommendation for adults between the ages of 19-50 years. Conclusion Long-term dieting can be a risk factor for several deficiency diseases and may endanger the health of individuals.