Oman today_ Research findings indicate that Body Mass Index (BMI)—one of the most common measures of body fat—remains within the normal range among people following different dietary patterns. However, the average BMI was highest among meat eaters and lowest among strict vegetarians, while pescatarians (fish eaters) and lacto-vegetarians (those who consume dairy products) fell somewhere in between.
According to the data, 7% of men and 9% of women who consumed meat were classified as obese, whereas obesity affected only 3–4% of men and women in the pescatarian and lacto-vegetarian groups, and just 2% among strict vegetarians.
Differences in body weight across these groups are likely related to daily caloric intake. Studies show that pescatarians and lacto-vegetarians consume about 4% fewer calories than meat eaters, while strict vegetarians take in approximately 14% fewer calories on average. This difference is largely due to the higher intake of fruits and vegetables in plant-based diets, as these foods provide fewer calories and less fat compared to fatty meats or full-fat dairy products.
Another factor highlighted in the study was the participants’ age. The average age of vegetarians ranged from 20 to 30 years, whereas most individuals following a meat-based diet were between 40 and 50 years old. In all dietary groups, BMI tended to increase by one to two percent with age. Therefore, the higher average BMI among meat eaters may partly be explained by the greater number of middle-aged individuals in that group.
Overall, the effect of a vegetarian diet on body weight depends primarily on total caloric intake, rather than simply eliminating meat from one’s meals.
A healthy diet—whether entirely plant-based or inclusive of dairy, fish, eggs, or lean meat—is most effective when it emphasizes fruits, vegetables, and whole grains. Even when combined with small amounts of healthy fats and nuts, such a diet typically provides significantly fewer calories than a high-fat, fast-food–based diet.
However, vegetarianism alone does not guarantee weight loss. Excess consumption of sugary drinks, chips, or sweets can still lead to calorie surplus and fat storage. For effective weight management, it’s crucial to understand where those extra calories are coming from.
Ideally, the bulk of your meals should consist of low-calorie plant-based foods such as fruits, vegetables, and whole grains. If you prefer to avoid meat, fish, poultry, or lean meats can serve as suitable alternatives. Ultimately, what matters most is portion control and mindful eating—overeating, even with a healthy diet, will still prevent weight loss.