Background: Nutrition has relevant role in the pathogenesis of dementia. However, in Latin American Countries (LAC), it is unknown which type of diet the subjects with dementia and cognitive dysfunction have. Objective: The main purpose of this study was to determine micro- and macronutrients and food frequency intake among the LAC population with mild cognitive impairment (MCI) and dementia. Methods: A systematic review using PubMed, Cochrane, Lilacs, and Scielo databases. Energy intake as well as micro- and macronutrients intake were analyzed using a random-effect model and presented in a forest plot. Results: Nine articles were included, an estimated energy intake of 1598.47 kcal (95% CI 1351.07–1845.88) was obtained. A daily consumption of 73.64 g/day (95% CI 64.07–83.2) of protein; 262.17 g/day (95% CI 214.51–309.93) of carbohydrates, and 57.91 g/day (95% CI 49.16–66.66) of fats were reported. A micronutrients daily intake consumption of 201.35μg/day of vitamin B9 (95% CI 125.32–277.38); 5.61μg/day of vitamin B12 (95% CI 2.53–8.70), and 139.67 mg/day of vitamin C (95% CI 59.33–220.02). Mineral intake of 637.32 mg/day of calcium (95% CI 288.54–986.11) and 9 mg/day of iron (95% CI 2.28–15.71) was obtained. A low intake of fruits and vegetables was found. Conclusion: Individuals with MCI and dementia from LAC have a nutritional deficiency characterized by a lower intake of fruits and vegetables, a high consumption of carbohydrates and protein, adequate fats intake and vitamins B12, vitamin C, and iron consumption, but a low intake of vitamin B9 and calcium.