Animals vs. Plants: Good or Bad for Your Health?

The environmental and health concerns of eating meat have been in the news lately, and meatless burgers seem to be the next new fast food craze.

Many of us like eating meat, but is it really necessary for our health? And is plant-based food the answer? 

There are many delicious-looking alternatives to meat on the market, and the food industry is quick to catch on. But let’s stop for a second and think before we take advice from marketers on what is best for our health.

Each person should make their own decision about what is right for them, but below are few things to consider when making choices to benefit both your health AND the environment.

Do I Have to Eat Meat to Get Enough Protein?

Actually, ‘meat’, or ‘red meat’ as it is commonly called due to its appearance, refers mainly to beef, pork, and other land mammals, but there are many other types of complete protein. Protein, along with carbohydrates and good fat, are the three main food groups (macronutrients) we need on a daily basis to stay healthy. However, red meat actually makes up only a small subset of the category of foods labeled as ‘protein’. 

Other commonly known categories of protein include poultry (e.g. chicken, turkey, duck, quail), seafood (fish and shellfish), game (e.g. venison), and vegetable sources (e.g. beans combined with rice). So the good news is, there are many other ways to get enough protein from animal sources besides red meat! 

For athletes, there are many known benefits of eating red meat as an important source of iron, B12, zinc, and other nutrients (1, 2, 3). If you are making any changes to your diet, see a nutritionist or your doctor to help you determine what changes are right for you.

How Much Protein Do I Need?

To be a quality protein source, the food has to contain all 20 of the essential ‘amino acids’, the building blocks of all cells. This is important because our bodies only make 11 out of the 20 essential amino acids required on a daily basis, and we must consume the other 9.

This food is then referred to as complete protein source. Our bodies digest those foods and use what is left over to produce molecules then called proteins, which then become the building blocks of cells and tissues.  It is important for your health to get enough of this food source in your diet on a daily basis to support essential functions such as build muscle, respond to stress, and maintain the immune system. 

The amount of protein we need on a daily basis varies depending on your age, height, weight, and activity. The Centers for Disease Control and Prevention recommends between 10-35% of your diet as protein, or about 46 grams for women and 56 grams for men (4). For food conversions, there are about 7 grams in 1 ounce (in contrast to the weight conversion, which is 28g=1 ounce) (30). This translates to about half a pound (~8 ounces) per day for men and ~6 ounces for women.

If you are more active, the National Strength and Conditioning Association recommends between 1.0 and 1.8 grams per kilogram of body weight, per day. If you are less active, divide your weight in pounds by 2.2 and that’s how many grams per day you need. For example, if you are a 130-pound female who is not very active, you need ~59 grams of protein per day.  In contrast, a 200-pound male who is very active would need about ~163 grams per day*.

What Foods Have Complete Protein?

All mammal sources of meat, poultry, fish, and game are solely made up of complete protein and are quality sources for this nutrient group. In addition to the easily digestible protein they contain, they also have a variety of health benefits, such as contributing to proper brain function and building muscle (1, 2, 3, 4, 22, 23, 24, 25, 26, 27).

In contrast, most vegetable sources like beans and rice also contain carbohydrate, as well as a fibrous casing. While vegetables can provide an added benefit of fiber and carbohydrates and an important and essential nutrient group, overeating carbohydrates at one sitting or as a ratio of your overall calorie intake (e.g. more than 70%) can spike blood sugar and lead to fat storage, which is associated with obesity and diabetes.  In contrast, complete proteins from non-vegetable sources do not contain any carbohydrate. In addition, although eating the combination of beans and rice at some point in the day could meet your needs, the casing on the plant proteins takes energy to break down, and there is a net loss of grams of protein for that food. 

It is also important to consider both the pros and cons of eating vegetable sources. Many vegetables do contain nutrients, fiber, and protein, and a plant-based diet has been shown to be associated with lower risk of stroke, cancer, heart disease, type 2 diabetes, and lower cholesterol (9, 17, 18, 19, 20, 21). However, these studies have more recently been found to be associated with the healthier lifestyles of plant-based eaters rather than with the plants themselves (22, 23).  

However, many vegetable sources lack some important vitamins and minerals such as heme for red blood cells, and Vitamins D and B12 (2, 3, 4, 5). Most vegetable sources also need to be combined at some point during the day to provide the complete amino acid profile (REF). Plant products that are exceptions to this rule include quinoa, soy, tofu, and tempeh. Due to the important individual factors in meeting nutrient needs, vegetarians and vegans should see a nutritionist to decide the best foods for them. See Table 2 below for some common complete vegetable protein combinations.

If you do eat beef, sourcing from local, organic, or biodynamic farms will be more likely to ensure both the quality of the food and considerate use of land. Eating high quality meat is important because the fat in conventionally raised beef and pork can be dangerous to our health due to contaminants such as antibiotics, toxins, hormones, and heavy metals (29, 31, 32, 33). In contrast, the fat contained in organic beef and pork is an excellent source of good fat and keeps you full longer.

Table 1: Food Sources of Complete Proteins.


*Calculation for  130-pound female:   ~56 kilograms x 1.0 grams/kilogram =  56 grams   *Calculation for  200-pound male:   ~90.9 kilograms x 1.8 grams/kilogram =  163 grams

*Calculation for 130-pound female:

~56 kilograms x 1.0 grams/kilogram = 56 grams

*Calculation for 200-pound male:

~90.9 kilograms x 1.8 grams/kilogram = 163 grams

Protein Sources to Avoid. 

Conventionally-raised beef, chicken, and pork. These animals are typically higher in fat, hormones, and heavy metals usually due to unnatural living conditions and a high-fat diet. Eating these foods often can increase cholesterol and weight gain for the general population, but will be less likely to affect athletes since they will burn off the fat. However, bacon and deli meats often contain preservatives.  They should be consumed as condiments (a side) in their nitrite-free versions if possible. Since the fat in this meat contains many hormones and additives (e.g. heavy metal residues), be sure to trim the fat off conventionally-raised meat (12, 13, 14, 15, 16). 

Chicken is a leaner animal with less fat overall, so the toxins in the fat are not much of a risk. However, the animals are often kept close together and have a higher incidence of disease. Both antibiotics and growth hormones are often included in their diets. These substances then appear in the food and in our bodies and pose a number of personal and public health concerns (8).  Choose ‘free range’ chicken and organic meat when possible.

Processed Red Meat: Not all red meat is created equal. Processed meats have been cured or salted to preserve color and/or flavor and include sausage, salami, ham, smoked or canned meat, cured bacon, corned beef, hot dogs, and beef jerky. These foods have known health risks, such as heart disease, cancer, and diabetes (see 8 for review). These risks are due to the carcinogens or their pre-cursors used in the preserving process, as well as the likelihood of the presence of hormones and heavy metals in these processed meats. Sliced, fresh, or frozen red meat is ‘unprocessed’ and considered generally healthy (10, 11, 12, 13).

Farm-raised fish. These animals are typically higher in fat, usually due to an unnatural, high-fat diet. Look for ‘wild caught’ whenever possible.

Excessive dairy. Dairy contains two types of proteins (casein and whey), but it also contains carbohydrate (the lactose) and fat. Although the healthy part of dairy is the fat (for review, see 36), similar to the health concerns of red meat, products from conventionally-raised animals often contain hormones and toxins and heavy metals in the fat (32,33). For full fat dairy products, choose organic. For conventionally raise products, choose skim or low-fat, but try to avoid the added sugar in many products used to increase fullness (35). Dairy as a main food group has a variety of negative health effects from weight gain to digestive problems and lactose intolerance (34).

Table 2: Pros and cons of vegetable sources


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Protein Sources to Eat Often. 

Lean meats like free range chicken and eggs. One study found a 27% lower risk of stroke by replacing 1 serving of red meat per day with 1 serving of chicken per day (14). Another study found eating eggs at breakfast is associated with reduced weight gain and increased fullness throughout the day (27).

Organic beef. Organic red meat has benefits for health and weight loss, as well as many nutrients not found in vegetable sources (2, 3, 5, 6, 7, 8, 9, 12, 13, 14, 15, 16, 19, 24, 29, 31, 32,33).

Fish and seafood. Studies show a reduced risk of heart disease with consumption of fish and seafood (25), even up to 15% (26). 

Takeaway

A mix of animal and plant-based proteins. Eating protein from animal sources has the added benefit of increasing muscle mass even in older individuals. Both plant and animal sources have important benefits to health while minimizing the risks of consuming only one or the other (28, 29).