More than 6.1 million Germans said they were vegetarian last year, up 400,000 from two years earlier, according to a survey by the Allensbach Institute. A large study at the Max Planck Institute for Human Cognitive and Brain Sciences (MPI CBS) in collaboration with the University Hospital of Leipzig has now examined in nearly 9,000 people how such nutrition relates to body and mind — regardless of age, gender and education level.
It has been found that the lower the proportion of animal foods in a person’s diet, on average the lower their body mass index (BMI) and thus their body weight. One reason for this may be the low proportion of heavily processed foods in plant foods. “Products rich in excess fat and sugar are particularly fattening. They stimulate hunger and delay the feeling of satiety. If you avoid animal foods, you eat less of such products on average,” explained Evelyn Medawar, first author of the underlying publication. , which is now published in the journal nutrients. Also: Vegetarian foods contain dietary fiber and have a positive effect on the gut microbiome. This is another reason why they can fill you up earlier than those made from animal ingredients. “People who eat mainly plant foods may therefore absorb less energy,” adds Medawar. In addition to a changed sense of satisfaction, lifestyle factors such as more sports and greater health awareness may also play a determining role.
For BMI it seems to make a difference which animal products a person eats. If it is mainly so-called primary animal products, such as meat, sausages and fish, the person usually has a higher BMI than a person who eats secondary animal products such as eggs, milk, dairy products, cheese and butter. In the former case the correlation is statistically significant.
Medawar uses an example to illustrate what this might mean for nutrition: “A person with an average BMI of 1.2 points either completely avoids certain animal products, such as primary products, and is on a vegetarian diet. Or he continues to eat meat. And fish. .
Nutrition and personality
Researchers have also found that a vegetarian or vegan diet is also related to personality. Especially one of the five major personality factors, extraversion. It was shown that people whose diet consisted mainly of plant-based foods were more introverted than those who ate mainly animal products. “It’s hard to say what the cause is,” says Veronica Witte. “This may be because more introverted people have more restrictive eating habits or are socially isolated because of their eating habits.” Here, again, further study should follow how people identify with their food attributes.
However, they could not confirm that a plant-based diet is associated with a tendency toward neurotic behavior, as other studies have suggested. “Previous analyzes showed that more neurotic people were generally more likely to avoid certain groups of foods and behave more restrictively. We focused here only on avoiding animal products and could not observe any relationship,” explained study leader Veronica Witt.
In the third part, they finally focused on the question of whether a predominantly plant-based diet is often associated with depressed mood. Previous studies here have also suggested a relationship between the two factors. “We couldn’t detect this correlation,” Witt said. “It’s possible that other factors in previous analyzes confounded the results, including BMI or specific personality traits known to be associated with depression. We accounted for those,” Witt said, explaining possible reasons for the different results. Additionally, plant-based diets are now more common and more accepted and are no longer restricted to a specific group.
The scientists investigated these connections within the so-called LIFE project, a broad-based study in collaboration with the Leipzig University Hospital. They determined individual diets through questionnaires in which participants were asked to fill in how often they had eaten individual animal products in the past 12 months — from “several times a day” to “never.” Personality traits such as extraversion and neuroticism were assessed with the so-called Personality Inventory (NEOFFI), while depression was assessed with the so-called CESD test, a questionnaire that records various symptoms of depression.