A 2017 review found evidence that practice of a<unk>  could lead to a decreased risk of cardiovascular diseases, overall cancer incidence, neurodegenerative diseases, diabetes, and early death. A 2018 review showed that practice of the<unk>  may improve overall health status, such as reduced risk of non-communicable diseases, reduced total costs of living, and reduced costs for national healthcare. A 2016 review found similar weight loss as other diets. The US 2015–2020 national guidelines devised a "Healthy<unk> -Style Eating Pattern", assessed against and mirroring the<unk>  patterns and its positive health outcomes. It was designed from the "Healthy U.S.-Style Eating Pattern", but it contains more fruits and seafood, and less dairy. In the 2020s, research on the<unk>  indicates that a<unk>  may contribute to health. Cardiovascular diseases The<unk>  is included among dietary patterns that may reduce the risk of cardiovascular diseases. A 2013 Cochrane review found limited evidence that a<unk>  favorably affects cardiovascular risk factors. A 2013 meta-analysis compared<unk> , vegan, vegetarian, low-glycemic index, low-carbohydrate, high-fiber, and high-protein diets with control diets. The research concluded that<unk> , low-carbohydrate, low-glycemic index, and high-protein diets are effective in improving markers of risk for cardiovascular disease and diabetes, while there was limited evidence for an effect of vegetarian diets on glycemic control and lipid levels unrelated to weight loss. However, reviews of early 2016 have been more cautious: concerns were raised about the quality of previous systematic reviews examining the impact of a<unk>  on cardiovascular risk factors, further standardized research has been found to be necessary, and the evidence for the possible prevention of vascular disease by the<unk>  was "limited and highly variable". Reviews in 2016-17 reached similar conclusions about the ability of a<unk>  to improve cardiovascular risk factors, such as lowering the risk for hypertension and other cardiovascular diseases. The<unk>  is low in saturated fat with high amounts of monounsaturated fat and dietary fiber. One possible factor is the potential health effects of olive oil in the<unk> . Olive oil contains monounsaturated fats, most notably oleic acid, which is under clinical research for its potential health benefits. The European Food Safety Authority Panel on Dietetic Products, Nutrition and Allergies approved health claims on olive oil, for protection by its polyphenols against oxidation of blood lipids and for the contribution to the maintenance of normal blood LDL-cholesterol levels by replacing saturated fats in the diet with oleic acid (Commission Regulation (EU) 432/2012 of 16 May 2012). A 2014 meta-analysis concluded that an elevated consumption of olive oil is associated with reduced risk of all-cause mortality, cardiovascular events and stroke, while monounsaturated fatty acids of mixed animal and plant origin showed no significant effects. The American Heart Association discussed the<unk>  as a healthy dietary pattern that may reduce the risk of cardiovascular diseases. Diabetes In 2014, two meta-analyses found that the<unk>  was associated with a decreased risk of type 2 diabetes, findings similar to those of a 2017 review. The American Diabetes Association and a 2019 review indicated that the<unk>  is a healthy dietary pattern that may reduce the risk of diabetes. Cancer A meta-analysis in 2008 found that strictly following the<unk>  was correlated with a decreased risk of dying from cancer by 6%. Another 2014 review found that adherence to the<unk>  was associated with a decreased risk of death from cancer. A 2017 review found a decreased rate of cancer, though evidence was weak. An updated review in 2021 found that the<unk>  is associated with a lower risk of cancer mortality in the general population. Weight loss in obesity Overweight adults who adopt<unk> s may lose weight by consuming fewer calories. A 2019 review found that the<unk>  may help obese people lower the quantity and improve the nutritional quality of food intake, with an overall effect of possibly losing body weight. Cognitive ability A 2016 systematic review found a relation between greater adherence to a<unk>  and better cognitive performance; it is unclear if the relationship is causal. According to a 2013 systematic review, greater adherence to a<unk>  is correlated with a lower risk of Alzheimer's disease and slower cognitive decline. Another 2013 systematic review reached similar conclusions, and also found a negative association with the risk of progressing from mild cognitive impairment to Alzheimer's, but acknowledged that only a small number of studies had been done on the topic. Major depressive disorder There is a correlation between adherence to the<unk>  and a lower risk of depression. Studies on which these correlations are made are observational and do not prove cause and effect. Gluten As the<unk>  usually includes products containing gluten like pasta and bread, increasing use of the diet may have contributed to the growing rate of gluten-related disorders.
Mediterranean diet
DASH diet
Plant-based diet
Rice diet
Western pattern diet
Stillman diet
Fad diet
BRAT diet