Are Meat Eaters Fatter Than Vegetarians? Unpacking the Science Behind Diet and Weight

November 5, 2025 •

4 min read

According to a 2022 review of 22 studies, vegetarian and vegan diets are significantly associated with reduced body mass index and weight loss. This leads many to question: are meat eaters fatter than vegetarians? While population studies suggest a trend, the full answer is more complex than just abstaining from meat.

Quick Summary

Observational studies consistently show vegetarians and vegans typically have lower body mass indices than meat-eaters. Factors like higher fiber intake, lower energy density, and different lifestyle habits play key roles in these differences, though diet quality and processing are ultimately more important than the presence of meat alone.

Key Points

Vegetarians and Vegans Have Lower Average BMI: Multiple large-scale studies, including EPIC-Oxford, have found that vegetarians and particularly vegans tend to have a lower average BMI than meat-eaters.
The Quality of the Diet Matters Most: The lower weight is primarily driven by the overall nutritional quality of the diet, such as higher fiber and lower saturated fat, and not simply the exclusion of meat.
Higher Fiber Promotes Satiety: The high fiber content in whole plant foods helps increase feelings of fullness, which can naturally reduce overall calorie intake.
Lifestyle Factors Play a Role: Healthier lifestyle habits often seen in vegetarian populations, like higher rates of exercise and general health consciousness, contribute to better weight outcomes.
Processed Food is a Key Determinant: The consumption of highly processed foods, whether meat-based or vegetarian, is strongly linked to weight gain. A healthy diet, regardless of category, emphasizes whole, unprocessed foods.
Lean Meat Does Not Hinder Weight Loss: Studies show that weight loss and body composition improvements are achievable on high-protein diets that include lean beef, demonstrating that lean meat itself is not necessarily fattening.

The Statistical Snapshot: Lower BMI in Vegetarians

For years, observational studies have shown a consistent trend: individuals following vegetarian and vegan diets tend to have a lower average body mass index (BMI) than their meat-eating counterparts. A landmark study, the EPIC-Oxford analysis of over 38,000 individuals, found that meat-eaters had the highest average BMI, followed by fish-eaters, then vegetarians, and finally vegans with the lowest BMI. A more recent systematic review from 2022 confirmed this association, with most reviewed studies showing a positive relationship between a plant-based diet and favorable body composition outcomes.

But these are population-level averages, and the reasons behind them are multifaceted. The distinction is not simply about what is or is not on the plate, but rather the nutritional characteristics of the overall dietary pattern and the accompanying lifestyle factors.

Why the Difference? Key Nutritional Factors

The composition of a typical plant-based diet offers several nutritional advantages that support lower body weight, which explains the general trend observed in research. Key nutritional differences include:

Higher Fiber Intake: Plant-based foods are rich in dietary fiber, which is known to promote satiety, or the feeling of fullness. A high-fiber diet can reduce overall calorie intake naturally, as people tend to feel full faster and for longer. Meat-eaters, especially those with diets low in fruits, vegetables, and whole grains, may not consume enough fiber.
Lower Energy Density: Whole plant foods like fruits, vegetables, legumes, and grains tend to have a lower caloric density than many meat-based dishes, meaning they contain fewer calories per gram. This allows individuals to consume a greater volume of food for the same number of calories, which aids in weight management without feelings of deprivation.
Lower Saturated Fat: Meat and dairy products can be significant sources of saturated fat. While fat is a necessary nutrient, excessive intake of saturated fat is linked to weight gain and chronic diseases. In contrast, vegetarian and vegan diets are typically lower in saturated fat.
Macronutrient Balance: The EPIC-Oxford study found that differences in macronutrient intake, particularly high protein and low fiber, were strongly associated with increasing BMI. Vegetarians often have a balance that favors higher fiber and moderate protein from plant sources like legumes and nuts.

Beyond the Plate: Lifestyle and Behavioral Differences

Research has also shown that people who choose vegetarian or vegan diets often exhibit other lifestyle habits that contribute to better weight outcomes. These are important confounding factors that influence the simple 'meat eater vs. vegetarian' comparison.

Greater Health Consciousness: Multiple studies note that vegetarians tend to be more health-conscious overall. They may be more likely to exercise regularly, drink less alcohol, and smoke less than the average meat-eater. These healthier behaviors independently support a lower body weight.
Avoidance of Processed Foods: Many plant-based diets naturally involve a lower intake of highly processed, energy-dense convenience foods. Processed meat intake, in particular, has been linked to weight gain and larger waist circumference. However, a vegetarian diet relying heavily on processed snacks, sugary beverages, and refined grains can still lead to weight gain, as highlighted by the Mayo Clinic.

Not All Meat or Vegetarian Diets Are Equal

It's a mistake to generalize and assume all meat-eaters or vegetarians are alike. The quality of the diet within each category is arguably more important than the category itself. For example, a diet rich in lean meats, fish, vegetables, and whole grains could be just as healthy, if not healthier, for weight management than a vegetarian diet of highly processed snacks and sugary foods. The critical factor is often the nutritional quality of the overall diet.

Comparing Diet Types: A Closer Look

To better understand the differences, here is a comparison of general trends associated with different dietary patterns. It's important to remember that these are average observations and individual diets can vary widely.


Feature	Meat-Eaters	Vegetarians	Vegans
Average BMI	Highest (e.g., 28.8 kg/m$^2$ in one study)	Lower (e.g., 25.7 kg/m$^2$)	Lowest (e.g., 23.6 kg/m$^2$)
Energy Density	Typically higher	Lower	Lowest
Saturated Fat Intake	Typically higher	Lower, but varies depending on dairy/cheese consumption	Lowest
Dietary Fiber Intake	Typically lower	Higher	Highest
Associated Weight Gain	More common over time	Less common, particularly when based on whole foods	Least common
Processed Food Intake	Higher on average, especially processed meats	Varies widely; can be high if relying on processed alternatives	Varies widely; can be high if relying on processed alternatives

Conclusion: The Final Verdict on Weight and Diet

The simple answer to "Are meat eaters fatter than vegetarians?" is that, on average, they tend to be. However, this average trend does not tell the whole story. The difference is not a direct result of meat consumption alone but rather a combination of numerous factors. Plant-based diets typically contain more fiber and less saturated fat, which supports lower energy intake and better weight management. Furthermore, the overall health-conscious lifestyle often adopted by vegetarians and vegans plays a significant role through factors like increased physical activity and a lower intake of processed foods.

Ultimately, whether a person is overweight depends more on the quality of their dietary choices and lifestyle habits than on the inclusion or exclusion of meat. Both meat-eaters and vegetarians can maintain a healthy weight and body composition by focusing on a balanced diet rich in whole foods and limiting processed options. The key is mindful eating, regardless of dietary label, to achieve and maintain a healthy weight and overall well-being. A high-protein diet that includes lean meats can also be effective for weight management, highlighting that a nutritious, well-planned diet is the most important factor.

For more information on the health benefits of meatless meals and diet quality, the Mayo Clinic provides excellent resources online.

Frequently Asked Questions

No, a vegetarian diet is not automatically healthier or less fattening. While studies show lower average body weights, the health benefits and weight outcomes depend heavily on the quality of the diet. A 'junk food' vegetarian diet high in refined carbohydrates, processed foods, and added sugars can still lead to weight gain.

The main reasons are the nutritional differences in typical vegetarian diets, which are generally higher in fiber and lower in saturated fat and caloric density compared to average meat-eating diets. Additionally, lifestyle factors, such as higher health consciousness and exercise rates, play a significant role.

Yes. A meat-eater can be healthier and leaner than a vegetarian by focusing on a diet of whole, unprocessed foods, including lean meats, and maintaining a healthy, active lifestyle. The key determinant is the overall quality of the diet and lifestyle, not simply the consumption of meat.

Diet quality is more important than the diet type. A diet rich in fruits, vegetables, whole grains, and lean protein—whether plant-based or including lean meats—is more beneficial for weight management than a diet high in processed foods and refined carbohydrates, regardless of its label.

Fiber, which is abundant in plant foods, promotes satiety or a feeling of fullness. This helps control appetite and reduces overall calorie intake naturally, as people are less likely to overeat when they feel satisfied.

Yes. Studies have linked higher intake of processed meats specifically to increased weight and central obesity, which refers to fat around the waist. Lean, unprocessed meat, on the other hand, can be part of an effective weight-management diet.

Some studies suggest that weight gain over time may be smaller in vegans compared to meat-eaters, but it is not entirely prevented. All dietary patterns, if not mindfully managed, can lead to weight gain over time due to factors like aging and decreased metabolism.