The Core Difference. Vegans eat no animal products, while vegetarians don’t eat animals, but may eat products that come from them (such as dairy and eggs). People typically choose these diets because of health concerns, religious restrictions or moral concerns about harming animals. And non vegetarian simply means the food which contains flesh.

     Studies have shown that, over time, vegans and vegetarians have lower rates of chronic disease. However, vegan and vegetarian diets aren’t automatically healthier, Fricke says. “Many meat substitutes are highly processed foods,” Fricke points out.

      According to experts and studies, vegetarians happen to be leaner as compared to non-vegetarians. Not only this, vegetarians have a healthier BMI, controlled blood pressure and low cholesterol as well. Maintaining weight in a long run is easier if you are on a vegetarian diet.

        In a British study, 9,668 men who were partners of pregnant women took the Edinburgh Postnatal Depression Scale. Seven percent of the vegetarians obtained scores indicating severe depression compared to four percent of non-vegetarians.  

In a 2018 study of 90,000 adults, French researchers examined the impact of giving up various food groups on depressive symptoms among meat eaters, vegans, true vegetarians, and vegetarians who ate fish. The incidence of depression increased with each food group that was given up. People who had given up at least three of four animal-related food groups (red meat, poultry, fish, and dairy) were at nearly two-and-a-half times greater risk to suffer from depression.  

Investigators from the College of William and Mary examined depression among 6,422 college students. Vegetarian and semi-vegetarian students scored significantly higher than the omnivores on the Center for Epidemiologic Depression Scale.     

In 2014, Austrian researchers published an elegant study of individuals who varied in their diets—330 vegetarians, 330 people who consumed a lot of meat, 330 omnivores who ate less meat, and 330 people who consumed a little meat but ate mostly fruits and veggies. The subjects were carefully matched for sex, age, and socio-economic status. The vegetarians were about twice as likely as the other groups to suffer from a mental illness such as anxiety and depression. (Here is the full text of the paper.)  

A study of 140 women found that the odds of depression were twice as great in women consuming less than the recommended intake of meat per week. (The researchers also found that women eating more than recommended amount were also likely to be depressed.) 

An article published in the journal Neuropsychobiolgy reported that the frequency of Seasonal Affective Disorder was four times higher among Finnish vegetarians and three times higher in Dutch vegetarians than in meat eaters.

       The studies above, which involved a total of 131,125 subjects, found that vegetarians are more likely than meat eaters to suffer from depression. However, I also located three studies involving 1,244 subjects that came to different a conclusion. 

Conclusively, Both vegetarians and vegans choose not to eat meat and fish. However, veganism is a stricter form of vegetarianism that prohibits the consumption or use of any products that come from animals, including dairy, eggs, honey, leather goods, wool, and silk.Vegetarians may eat dairy products, eggs, honey, and other byproducts that do not involve the slaughter of animals. However, there are several variations of the vegetarian diet. For example, some vegetarians choose to eat eggs but not dairy products.

       Vegan and vegetarian diets generally include a range of fruits, vegetables, nuts, seeds, grains, and pulses, as well as “meat substitutes” that derive from these food types.

          Both vegetarian and vegan diets may provide health benefits, including reduced body weight, lower cholesterol levels, and decreased risk of cardiovascular disease.                    

        However, it is important for vegetarians and vegans to ensure that they are meeting all of their nutritional requirements. For example, plants do not naturally contain vitamin B-12, so vegans and vegetarians may need to consume fortified foods or take dietary supplements to get enough vitamin B-12.