In an observational study, researchers compared the weight and BMI of 55,459 women who identified themselves as either omnivores, semi-vegetarians, lacto-vegetarians or vegans. For purposes of this study:
An omnivore was defined as someone whose diet included meat, poultry, fish, eggs and dairy products.
A semi-vegetarian was defined as eating no meat or poultry but whose diet included fish, eggs and dairy products.
A lacto-vegetarian was defined as eating no meat, poultry, fish or eggs but whose diet included dairy products.
A vegan was defined as someone who did not eat any meat, poultry, fish, eggs or dairy products.
The study concluded that the women who are semi-vegetarian, lacto-vegetarian or vegan are less likely to be overweight or obese than their omnivore counterparts. The researchers suggested that it would help individuals control their weight if they were to consume more plant foods and less animal products.