Animal vs. Plant-Based Protein: Which Is Better for Weight Management?

The kind of protein you’re eating could play an important role in managing a healthy weight.

Now more than ever, people are focused on hitting their protein goals. But it’s not just the amount of protein you get that’s important—where it comes from is also key.

Protein is essential for the body to function and can be found in a wide variety of foods, including everything from low-fat dairy to tofu. However, not all sources of protein are created equally.

Generally speaking, people can get protein from animal sources—this includes chicken, fish, and eggs—or they can get protein from plant-based sources, such as nuts, lentils, beans, or whole grains.

And though many people associate protein with meat, experts say plant-based options may be the healthiest option, particularly for people looking to lose or manage their weight.

“The data has started to demonstrate more and more that plant protein is equally efficacious in terms of providing the nourishment needed for the human body,” Amanda Velazquez, MD, director of obesity medicine at Cedars-Sinai, told Health. “With plant-based protein, there’s more benefits as a whole compared to animal protein.”

Here’s how animal protein and plant-based proteins compare when it comes to weight loss, as well as how to prioritize protein in a well-balanced diet.

How Does Protein Play a Role in Weight Loss? 

No matter the source, protein is a great way to aid in healthy weight loss or management.

Since protein can improve a person’s metabolism, higher protein intake can lead to greater feelings of fullness, Amber Schaefer, MS, RDN, clinical nutrition lead and nutrition instructor at the Mayo Clinic College of Medicine and Science, told Health.2

And protein doesn’t just help people feel full—it can help people feel full for longer periods of time.

“[Each macronutrient] affects the body differently in terms of how long it takes for digestion and processing in the gastrointestinal tract,” said Velazquez. “For protein, it takes longer to break it down and, as a result, requires more energy.”

In addition to protein aiding in weight loss itself, it’s also a vital part of keeping the body healthy while people cut calories.

“Inadvertently, an individual is going to lose some degree of muscle mass when they’re losing weight in combination with fat mass,” said Velazquez. “So in order to preserve that muscle mass, it’s critical for one to be taking in adequate amounts of protein for their body.”

Overall, Plant-Based Protein Comes Out on Top

In terms of where to source protein from, experts agree that plant-based options tend to be healthier for the body as a whole.

For one, plant-based protein sources tend to have more fiber than animal protein.

“When it comes to weight loss, it’s especially important to be not only having high protein in the diet, but also a high fiber diet,” said Velazquez. “Animal protein is not going to have as high fiber as plant-based proteins.”

For example: A cup of black beans has about 42 grams of protein and about 30 grams of fiber.3 A half filet of yellowtail fish has about 43 grams of protein, but no fiber.4

The boost of fiber often associated with plant-based proteins can promote additional aspects of well-being.

“Plant-based proteins do incorporate fiber, of course, that also helps us to feel fuller longer and helps with our gut health and promotes regular bowel movements,” said Schaefer. “That in itself can help in weight management.”

Plant-based products also tend to be overall healthier for the body.5

It depends on the specific type of protein and how it’s cooked, but in general, plant-based proteins have fewer saturated fats than animal proteins, Schaefer explained.

“We do recommend to stay away from overly processed options, because that can, of course, give extra calories from saturated fat,” she said.

And, not only can processed foods be more caloric, but they also take more of a toll on the body.

Lunch meat, Velazquez said, is a good example of this—it’s often processed with nitrites, which have been associated with colorectal cancer.

More broadly, consuming large amounts of red meat—especially processed—has been linked to higher rates of type 2 diabetes, heart disease, and mortality.6

“If we overdo our consumption of animal-based products—so say we’re eating large amounts of steak or pork—over time, that can put a lot more stress on the body,” Schaefer said.

Prioritizing a Nutritious, Protein-Packed Diet is Key 

In general, the amount of protein adults need each day boils down to about 0.8 grams for every kilogram of body weight.

That means someone who’s 150 pounds needs about 55 grams of protein each day.

Whether it’s to lose weight or just to maintain health, people should try to get the right amount of protein for them every day.

Choosing where to get this protein from can be tricky. Products like protein powder can be easy additions to someone’s routine that help them hit their protein goals.

“It’s a processed item, so being very vigilant and reading the nutrition label is key when it comes to protein powders,” said Velazquez. “If they have not tried one before and are looking to try one, then I would encourage plant-based.”

Beyond just increasing protein intake with powders, the best thing to do is add more protein directly to your diet.

Plant-based protein may be the healthiest option, but that doesn’t necessarily mean that a person has to go vegetarian or vegan overnight, Schaefer explained. Instead, make swaps whenever possible.

“We do recommend at least getting three servings of some form of legume, whether that be lentils or chickpeas, or if you like, beans,” said Schaefer. “Just switching out maybe the red meat from that week so you’re reducing the amount of saturated fat that you’re getting.”

She emphasized that restricting all animal protein isn’t necessary to lose weight or maintain health, either.

“A balanced diet can incorporate both animal and plant-based proteins,” she said. “My typical recommendation is to get a combination of the two.”

In general, people should try “leaning towards plant-based proteins,” Velazquez said, but leaner proteins such as fish, seafood, chicken, and turkey are also good options if people do want to stick with some animal protein.

“The important thing to know is that quality matters,” she said.