An expert breaks down the facts about animal and plant proteins—and reveals which one you should prioritize in your diet.
Animal vs. Plant Proteins: An Expert Doctor Explains Why One Is Healthier
Published on Nov. 26, 2024
It’s no surprise that protein has become a hot topic in health conversations. It’s vital for building and repairing tissues, producing enzymes and hormones, and maintaining overall health. Whether you’re looking to build muscle, manage your weight, or simply sustain energy throughout the day, protein is a key player. With so many choices on the table, you might wonder: Should you focus on animal-based or plant-based protein sources?
“Animal and plant proteins can both be part of a healthy diet, but they have key differences that set them apart,” says Michelle Cardel, PhD, MS, RD, FTOS, Chief Nutrition Officer of WeightWatchers.
Ahead, Dr. Cardel offers a breakdown of what you need to know about these two types of proteins, dispels common myths, and shares expert tips on which type to prioritize for your health goals.
Sources of animal and plant proteins
Animal proteins, such as chicken, eggs, fish, and dairy products, are complete proteins, meaning they provide all nine essential amino acids in one source. These are especially beneficial for those looking to meet high protein needs or support muscle repair.
On the other hand, plant-based proteins are often incomplete but come with added health benefits, such as fiber, antioxidants, and lower levels of saturated fat. Some good plant-based protein options include lentils, beans, quinoa, nuts, and tofu.
How much protein do you need daily?
The amount of protein you need each day depends on factors like your weight, activity level, and health goals. According to the Cleveland Clinic, the general guideline is to consume 0.8 to 1 gram (g) of protein per kilogram (kg) of body weight daily. To calculate this, take your weight in pounds, divide it by 2.2 to convert to kg, and multiply by 0.8 or 1. For example, if you weigh 150 pounds, divide that by 2.2 to get roughly 68 kg. Multiply 68 by 0.8 and 1, and your daily protein intake should fall between 55 and 68 g.
If you’re focused on weight loss, protein needs may increase. An obesity expert suggests aiming for 1.0 to 1.2 g of protein per kg of your target weight to help maintain muscle while shedding fat.
Dr. Cardel explains that as long as you don’t have kidney issues or other health conditions affecting your protein needs, consuming 0.8 to 2 g of protein per kilogram of body weight (or per 2.2 pounds) is generally considered a healthy amount of protein.
Always consult your doctor if you have any questions about your specific protein needs.
Benefits of animal protein
“The biggest difference between animal and plant proteins is that animal proteins are ‘complete proteins,'” explains Dr. Cardel. This means they contain all nine essential amino acids that your body needs to build and repair tissues, maintain muscle mass, and perform critical bodily functions. She adds, “Animal protein sources have been linked to health benefits such as increased lean muscle mass and lower rates of cognitive decline, and they can supply other necessary nutrients such as vitamin B12, vitamin D, and iron, which can be harder to obtain through plant proteins.”
Benefits of plant protein
While some plant proteins, like edamame, tofu, and quinoa, are also complete proteins, many other plant foods are incomplete, lacking one or more of the essential amino acids. “However, you can combine incomplete protein sources to meet your body’s needs,” Dr. Cardel notes. For example, rice and beans, when eaten together, create a complete protein, with each food contributing the amino acids that the other lacks.
“Plant proteins are also full of fiber, antioxidants, and nutrients, and have less saturated fat than animal protein,” she continues. This makes plant-based proteins heart-healthy, gut-friendly, and a smart choice for lowering cholesterol levels.
Animal vs. plant protein: Which is better to eat?
Ultimately, both animal and plant proteins offer health benefits. However, she advises, “As a dietitian, I would encourage prioritizing plant proteins as a means for overall health, given their high fiber content and benefits for overall health.”
Animal vs. plant protein: Which is better for chronic medical conditions?
“Generally speaking, plant proteins have been associated with lower risks for chronic conditions like heart disease, stroke, type 2 diabetes, lower cholesterol levels and other chronic diseases,” explains Dr. Cardel.
She cites a study involving more than 48,000 women, which found that for every 3% increase in plant protein consumption, there was a remarkable 38% improvement in the likelihood of staying healthier. The study revealed that a diet rich in plant proteins was linked to significant health benefits, including improved physical mobility, reduced or no chronic diseases, better mental health, and healthier aging overall.
Disadvantages of animal protein
Dr. Cardel explains that while red meat consumption has been linked to an increased risk of heart disease and stroke in some studies, “the results are mixed because studies have often lumped processed and fattier red meats, like hot dogs and bacon, into the same category as unprocessed and leaner red meats.”
The negative health effects observed are primarily associated with processed meats or cuts high in saturated fat. Research points out that processed red meat—not unprocessed, lean red meat—poses a greater risk for coronary heart disease and diabetes.
“Contrary to what may be popular belief, lean red meat does not appear to negatively affect heart health,” Dr. Cardel clarifies. In fact, studies suggest that incorporating lean red meat into a balanced diet, in moderation, can help reduce LDL “bad” cholesterol levels. When diets rich in lean red meat are compared to those containing lean white meat, such as poultry or fish, many studies show similar heart health benefits. These include decreases in LDL cholesterol and increases in HDL “good” cholesterol.
For those who enjoy lean red meat, focus on options like sirloin and tenderloin. Bison is another healthier alternative, offering high protein content with lower fat levels. Regardless of your meat choice, remember to let vegetables take center stage on your plate, which add nutrients, fiber, and balance to your meals.
Disadvantages of plant protein
Plant proteins offer numerous benefits, but they do come with some challenges. Unlike animal proteins, plant-based sources vary in their amino acid composition, which can make it more difficult to meet the body’s essential amino acid requirements. “This requires more mindful consumption and larger quantities, but is still manageable,” explains Dr. Cardel.
It’s also important to note that not all plant-based foods are equally nutritious. For instance, fried vegetables or refined grains carry health risks and lack the nutritional value of whole, minimally processed options. Instead, focus on nutrient-rich choices like non-starchy vegetables, beans, lentils, and whole grains like corn and quinoa.
If you’re finding it challenging to meet your protein needs on a plant-focused diet, schedule a visit with a registered dietitian. They can provide personalized guidance to help you achieve your goals.
Can you build muscle on plant protein?
“Animal protein is typically more efficient in helping build muscle mass than plant protein,” explains Dr. Cardel. This is because animal proteins are “complete proteins,” and they are more readily absorbed by the body—key factors for muscle growth and repair.
However, with thoughtful planning and the inclusion of a variety of plant-based protein sources, a vegan or vegetarian diet can still effectively support muscle building, she concludes.
About the expert:
Michelle Cardel, PhD, MS, RD, FTOS, serves as the Chief Nutrition Officer for WeightWatchers. She is also an adjunct professor in the Department of Health Outcomes and Biomedical Informatics and the Associate Director of the Center for Integrative Cardiovascular and Metabolic Disease at the University of Florida.
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