What happens to your body when you start eating more meat?

October 16, 2025 •

3 min read

According to a 2019 review in the journal Annals of Internal Medicine, long-term consumption of high amounts of red and processed meat is associated with an increased risk of chronic diseases. If you start incorporating more meat into your diet, it's important to understand the immediate and lasting effects on your body, as the outcome is highly dependent on the type and quantity of meat consumed.

Quick Summary

This article details the effects of increasing meat consumption on the body, including immediate digestive shifts, potential muscle growth from high-quality protein, and altered energy levels. It also examines long-term risks like increased risk of heart disease and certain cancers, differentiating impacts based on meat type and preparation.

Key Points

Initial Digestive Adjustment: When increasing meat intake, expect initial digestive changes such as bloating, constipation, or heartburn, especially if reintroducing after a long time.
Potential for Increased Energy: Lean meat is a rich source of iron and vitamin B12, which can boost energy levels and combat fatigue.
Supports Muscle Growth: The high-quality, complete protein in meat is highly effective for building and maintaining muscle mass, especially when combined with exercise.
Increased Risk of Heart Disease and Cancer (with high intake): Excessive consumption of fatty red and processed meats is linked to a higher risk of heart disease and certain cancers due to saturated fats and other compounds,.
Alters Gut Microbiome: A low-fiber, high-meat diet can shift the balance of gut bacteria, decreasing beneficial microbes and increasing certain bile-tolerant organisms.
Moderation and Choice are Key: The health outcomes of eating more meat depend heavily on the type (lean vs. processed) and quantity consumed. Balancing with plant-based foods is crucial.

Immediate Effects of Increased Meat Consumption

When you first start eating more meat, especially after a period of low or no meat intake, your body will begin to adjust. The digestive system is often the first to show changes as it processes a different mix of nutrients.

Digestive Changes

Increasing meat intake can initially lead to digestive issues like bloating, constipation, and heartburn. This is because meat is high in protein and fat but lacks fiber, which can slow digestion. The body also needs to produce more stomach acid to break down meat, potentially causing heartburn.

Energy and Satiety

Meat is a good source of iron and vitamin B12, which are important for energy. Adding meat to your diet can increase energy levels and reduce fatigue if you were previously deficient. The high protein content also promotes satiety, helping you feel fuller for longer and potentially aiding in weight management.

Long-Term Impact on Body Composition and Health

Over time, a diet with more meat can have significant effects on body composition and health, depending largely on the type of meat consumed.

Muscle Growth and Maintenance

Lean meat provides complete protein with essential amino acids, supporting muscle repair and growth, particularly when combined with exercise.

Cardiovascular Health Risks

Consuming high amounts of red and processed meats, which are often high in saturated fat, is linked to heart health problems. Saturated fats can increase LDL cholesterol. Additionally, a compound called TMAO, produced when the gut processes L-carnitine from red meat, is associated with a higher risk of cardiovascular disease.

Increased Cancer Risk

Studies show a link between red and processed meat consumption and an increased risk of certain cancers, especially colorectal cancer. Processed meat is classified as a Group 1 carcinogen and red meat as Group 2A. Cooking methods that create carcinogenic compounds also contribute to this risk.

Kidney Function

A very high-protein diet from meat can strain the kidneys as they filter protein waste products. While not typically harmful for healthy kidneys, it can be a concern for those with existing kidney issues.

Changes to the Gut Microbiome

Diet influences the gut microbiome. A diet high in meat and low in fiber can alter gut bacteria, increasing bile-tolerant bacteria and reducing beneficial microbes that produce short-chain fatty acids.

The Importance of Meat Type and Preparation

Choosing the right types of meat and how you prepare them is crucial for health. Lean white meats are generally lower in saturated fat than red meats, and processed meats pose the highest risks. High-temperature cooking methods like grilling or frying can create harmful compounds, so opting for methods like baking or stewing is healthier.


Feature	Lean White Meat (e.g., chicken breast)	Lean Red Meat (e.g., sirloin)	Processed Red Meat (e.g., bacon)
Saturated Fat	Low	Low to Moderate	High
Protein Quality	High	High	Moderate (due to processing)
Micronutrients	Good source of B vitamins, zinc	Rich in iron, zinc, B vitamins	Varies; often high in sodium, nitrates
Associated Risks (High Consumption)	Lower (unless cooked improperly)	Heart disease, certain cancers	Heart disease, cancer, diabetes,

Balancing a Meat-Inclusive Diet

To incorporate meat into your diet healthily, focus on lean cuts, manage portion sizes (around 3 ounces), and balance your meals with plenty of fiber from vegetables, fruits, and whole grains. Prioritizing lean white meat and fish while limiting processed meats can help minimize health risks.

Conclusion

Adding meat to your diet can provide benefits like increased energy and improved muscle mass due to its protein, iron, and vitamin B12 content. However, initial digestive changes are possible. Long-term health outcomes, including risks of heart disease and cancer, are strongly influenced by the type of meat and how it's prepared. By selecting lean, unprocessed meats in moderation and pairing them with fiber-rich plant foods, you can gain the nutritional advantages while reducing potential negative health impacts.

For more detailed information on balanced diets, consult resources like the American Heart Association.

Frequently Asked Questions

Increased meat consumption, especially processed and fatty cuts, has been linked to weight gain. However, because meat is high in protein and very satiating, it can also help control your appetite, which may aid in weight management if you choose lean cuts and maintain a balanced diet.

Your body does not lose its ability to digest meat after abstaining for a period. However, you may experience some digestive discomfort initially, as your system adjusts to the denser protein and fat content. Start with small portions of lean meat and reintroduce it gradually.

Lean, unprocessed meats like chicken breast, fish, and lean cuts of pork or beef are healthier options. They offer high-quality protein and essential nutrients with less saturated fat. Processed meats should be minimized or avoided.

Yes, meat is an excellent source of complete protein, which provides all the essential amino acids needed for muscle synthesis. Combined with strength training, increasing your intake of lean meat can help build and maintain muscle mass.

Cooking methods like grilling, frying, or barbecuing at high temperatures can produce carcinogenic compounds called heterocyclic amines (HCAs). Opt for healthier methods like baking, broiling, or stewing to minimize this risk.

High consumption of fatty red and processed meat can increase blood cholesterol levels, raising your risk of heart disease,. Replacing these with lean meats, fish, or plant-based proteins can help lower this risk.

To minimize digestive issues, start slowly by incorporating small, 2-3 ounce servings of lean meat or fish every few days. Pair it with a variety of vegetables and fiber-rich foods to help your body adapt smoothly.