What happens to your body when not eating meat?

November 5, 2025 •

4 min read

Research suggests that reducing or eliminating meat can lead to a drop in blood cholesterol levels by as much as 35%. Understand what happens to your body when not eating meat and how a well-planned, plant-based diet can reshape your health.

Quick Summary

Eliminating meat can reduce cholesterol and inflammation while improving gut health, but a well-planned, nutrient-rich diet is crucial to avoid deficiencies in iron, vitamin B12, and other key nutrients.

Key Points

Improved Cardiovascular Health: Eliminating meat, especially red and processed varieties, can lower bad cholesterol and reduce the risk of heart disease.
Enhanced Gut Microbiome: The increased fiber from a plant-based diet promotes the growth of beneficial gut bacteria, leading to better digestive health.
Risk of Nutrient Deficiencies: Without proper planning, a meat-free diet can lead to deficiencies in essential nutrients like Vitamin B12, iron, and zinc.
Strategic Nutrient Absorption: Maximizing plant-based iron absorption requires pairing it with Vitamin C-rich foods and being mindful of inhibitors like tannins in tea and coffee.
Importance of Supplements: Vitamin B12 is not found in plant foods, making supplementation or fortified foods necessary for those on a vegan or strict vegetarian diet.
Potential for Weight Loss: Plant-based diets, often lower in calories and fat while higher in fiber, can aid in weight management.

For many, transitioning away from meat is a deliberate choice driven by health, environmental, or ethical concerns. While this dietary shift can usher in a host of positive changes, from improved cardiovascular markers to better gut health, it also requires a thoughtful approach to nutrition to prevent deficiencies. The effects on your body ultimately depend on what you choose to put on your plate to replace animal products.

Immediate Changes to Your Digestive System

One of the first things you may notice when you stop eating meat is a change in your digestive health. Animal-based diets, particularly those high in processed and fatty meats, tend to be low in fiber. A plant-based diet, conversely, is rich in fruits, vegetables, legumes, and whole grains, which are excellent sources of dietary fiber. This increased fiber intake can lead to:

A Shift in Gut Microbiome: Plant-based fiber acts as a prebiotic, feeding the beneficial bacteria in your gut. This can promote the growth of a diverse and healthier microbiome, which is associated with better digestive function and improved immune response.
Improved Digestion and Regularity: The added fiber can help regulate bowel movements and alleviate constipation. Some may experience temporary bloating as their system adjusts to the higher fiber load.
Reduced Inflammation: Plant-based diets are naturally anti-inflammatory due to their high content of antioxidants and other phytonutrients. Conversely, animal products can trigger inflammation. This reduction in inflammation can lead to a general feeling of improved well-being.

Long-Term Health Benefits

Beyond immediate digestive effects, a well-executed meat-free diet offers significant long-term health advantages:

Cardiovascular Health

Eliminating meat, particularly red and processed varieties, can significantly impact heart health. Plant-based diets are low in saturated fat and contain no cholesterol, which is only found in animal products. Studies show this leads to a reduction in LDL (bad) cholesterol and overall lower blood pressure, which in turn lowers the risk of heart disease and stroke.

Weight Management

Many studies have linked vegetarian and vegan diets with lower body mass index (BMI) and lower rates of obesity. This is likely due to the higher fiber content, which promotes satiety, and a reduced caloric intake from fatty meats. Replacing meat with whole, plant-based foods is key to achieving sustainable weight management.

Reduced Risk of Type 2 Diabetes

Research has shown that individuals who follow predominantly plant-based diets have a significantly lower risk of developing type 2 diabetes. The reasons for this are multi-faceted and include better weight management, improved insulin sensitivity, and the absence of compounds found in meat that can damage pancreatic cells.

Potential Nutritional Challenges and Solutions

While the health benefits are compelling, simply removing meat without careful planning can lead to nutritional deficiencies. Here’s how to navigate these challenges:

Protein Sourcing

Meat is a complete protein, containing all nine essential amino acids. However, it's a myth that plant-based diets can't provide sufficient protein. A variety of plant proteins throughout the day can provide all the necessary amino acids.

Top plant-based protein sources:

Legumes: Lentils, chickpeas, and beans
Soy Products: Tofu, tempeh, and edamame
Nuts and Seeds: Almonds, chia seeds, and hemp seeds
Whole Grains: Quinoa and oats
Dairy (Lacto-ovo vegetarian): Greek yogurt and cottage cheese

Iron Absorption

Iron from plant sources (non-heme iron) is less readily absorbed than iron from meat (heme iron). However, a well-planned vegetarian diet can still provide adequate iron. To maximize absorption, consume plant-based iron sources with foods rich in Vitamin C, such as citrus fruits, bell peppers, and broccoli.

The Vitamin B12 Challenge

Vitamin B12 is crucial for nerve function and red blood cell formation, and it is found naturally only in animal products. For this reason, those on a vegan diet must rely on fortified foods or supplements to meet their needs. Lacto-ovo vegetarians can get B12 from eggs and dairy.

Other Key Nutrients

Omega-3 Fatty Acids: While ALA is found in flaxseed and walnuts, EPA and DHA are more common in fatty fish. Vegans can use algae-based supplements to ensure adequate intake.
Zinc: Absorption of zinc can be inhibited by phytates in plant foods. Ensure adequate intake from sources like legumes, nuts, and whole grains.
Calcium and Vitamin D: Vegans need to rely on fortified plant milks, juices, and leafy greens for calcium, and may require supplements for Vitamin D.

Nutritional Comparison: Meat vs. Well-Planned Plant-Based Diet


Nutrient/Factor	Meat-Eating Diet (High in Red/Processed Meat)	Well-Planned Plant-Based Diet
Saturated Fat	Often high, contributing to heart disease risk	Very low or absent, reducing cardiovascular risk
Cholesterol	Present in all animal products	None present; can help lower blood cholesterol levels
Dietary Fiber	Low, often leading to digestive issues	High, promoting healthy gut bacteria and regularity
Vitamin B12	Readily available from animal products	Must be obtained from fortified foods or supplements
Iron (Bioavailability)	Heme iron is easily absorbed	Non-heme iron is less easily absorbed, requires strategic food pairing
Inflammation	Higher levels of chronic inflammation observed	Lower levels of chronic inflammation due to antioxidants

Conclusion

Choosing to stop eating meat can initiate a series of positive physiological changes, particularly regarding cardiovascular health, weight management, and gut function. However, these benefits are maximized only when the diet is thoughtfully planned to replace the nutrients previously supplied by meat. By focusing on a diverse array of whole plant foods and strategically managing key nutrients like Vitamin B12, iron, and protein, a meat-free diet can be a sustainable and healthy choice. For personalized guidance, consulting a registered dietitian is always recommended.

Learn More

For more in-depth information, the Harvard Health article on becoming a vegetarian is an excellent resource: Becoming a vegetarian - Harvard Health.

Frequently Asked Questions

No, you do not need meat to get enough protein. A wide variety of plant-based foods, such as beans, lentils, chickpeas, soy products, nuts, and seeds, can provide all the essential amino acids your body needs to build and repair tissues.

While plant-based iron (non-heme) is less absorbed than meat-based iron (heme), you can increase absorption by consuming iron-rich plant foods, such as lentils, fortified cereals, and spinach, along with a source of Vitamin C like citrus fruits.

For those on a vegan diet, or strict vegetarians, a Vitamin B12 supplement is essential, as this vitamin is only reliably found in animal products. Ovo-lacto vegetarians can get B12 from eggs and dairy, but many still opt for fortified foods or supplements.

Yes, many studies show that adopting a plant-based diet can lead to a significant drop in blood cholesterol levels. This is because plant foods are naturally free of cholesterol and often lower in saturated fat.

Your gut microbiome may change for the better. The increase in fiber from plant-based foods fosters the growth of beneficial gut bacteria, which can lead to improved digestion and a reduction in inflammation.

Yes, many people experience weight loss when switching to a meat-free diet. Plant-based foods are often higher in fiber, which can help you feel full, and generally lower in saturated fats and calories.

Some people may experience temporary digestive changes, like bloating, as their body adjusts to a higher fiber intake. The most significant long-term risk is nutrient deficiencies if the diet is not properly planned and supplemented.