There's a reason the Mediterranean diet has consistently ranked as one of the healthiest diets for decades. It involves eating high-antioxidant foods like fruits and vegetables and stresses the importance of grains, beans, legumes, nuts, seeds, olive oil, herbs, and spices. It also allowed for regular but limited consumption of poultry, eggs, cheese, and yogurt. For a more detailed breakdown, here's a 7-day Mediterranean diet meal plan. 

A plant-based diet is just what the name suggests—a diet that focuses only on foods that come from plants, not animals. This means nuts and seeds, fruits and vegetables, and legumes and grains. Just note: Plant-based eaters need to be diligent about avoiding artificial ingredients and added sugar, which can sneak their way into many plant-based foods. You can learn more about what a healthy plant-based diet looks like here. 

This one comes from the Dietary Guidelines for Americans, which are published by the USDA and U.S. Department of Health and Human Services and promote plant-based living as well as the consumption of lean animal products and reducing your intake of processed meats, inflammatory fats (like trans fats), and alcohol. It also advocates for quitting sugar.

This diet was developed by Harvard researchers and involved rating different foods in terms of their connection to risk factors for chronic disease. In a nutshell, this diet is very similar to the Mediterranean diet in that it encourages fresh vegetables and fruit, nuts and legumes, and fish and healthy fats. What stands out is that it specifically recommends avoiding potatoes (all potatoes but especially french fries), fruit juice, and refined grains.