A plant-based diet is any diet that focuses around foods derived from plant sources. This can include fruit, vegetables, grains, pulses, legumes, nuts and meat substitutes such as soy products.
People often have different interpretations of what ‘plant-based’ eating looks like. Some people still include small amounts of animal products such as meat and fish, while focusing mainly on vegetarian foods – this is referred to as a semi-vegetarian or flexitarian diet. Plans that cut out meat but still include fish are referred to as pescatarian diets. People who don’t eat meat or fish but still include dairy and eggs are referred to as vegetarian, while those who cut out any animal derived products, including dairy, eggs, honey and gelatin are referred to as vegan.
People following plant-based diets and consuming a wide variety of fruits, vegetables and pulses are likely to find it easier to meet their five-a-day target. Due to this, they are also likely to have good intakes of fibre and the vitamins and minerals that are present in fruit and vegetables, including folate, vitamin C and potassium, all of which are important for good health.
However, it is worth noting that ‘plant-based’ does not automatically mean 'healthy', particularly when it comes to processed and packaged foods. Technically, products such as refined sugar, white flour and certain vegetable fats can all be labelled ‘plant-based’ as they are vegetarian, but this does not mean that they should make up the bulk of a healthy diet.
Plant-based diets including vegan diets can be healthy, as long as they are balanced and nutritionally adequate. When followed consistently, a well-balanced, plant-based diet that focuses on wholegrains, fruit, vegetables, legumes, nuts and seeds may provide health benefits. These include a lower body mass index (BMI), lower cholesterol levels and a reduced incidence of chronic diseases including type 2 diabetes, heart disease and even protection from some cancers including prostate and breast cancer.
Like any diet, the health benefits are dependent on the quality and nutritional adequacy of the diet – this means replacing refined, typically ‘white’ carbohydrates with wholegrains, avoiding sugary, sweetened drinks and confectionery and focusing on good quality plant-based protein and fats, such as those found in nuts and seeds.
Source: https://www.bbcgoodfood.com/howto/guide/what-plant-based-diet