Which type of protein is more effective for weight management: animal or plant-based?

The type of protein consumed can be a crucial determinant in achieving and maintaining a healthy weight.

Increasingly, individuals are paying attention to their protein intake, however, not only the quantity, but also the source of protein is very significant.

Protein is a vital nutrient for our body and we can find it in a plethora of food items, from low-fat dairy to tofu, although not every protein source stands on an equal footing.

Protein can generally be obtained from animal-derived sources like chicken, fish, and eggs, or from plant-based sources such as nuts, lentils, beans or whole grains.

Contrary to the common association of protein with meat, experts recommend plant-based proteins as potentially healthier, especially for those aiming to lose or control their weight.

According to Amanda Velazquez, MD, director of obesity medicine at Cedars-Sinai, recent data is increasingly showing that plant protein nourishes the human body just as effectively. She added that plant-based proteins offer more benefits overall compared to animal proteins.

The comparison between animal and plant-based proteins in the context of weight loss, and how to emphasize protein in a balanced diet are discussed hereafter.

Regardless of where it originates, protein can be a key contributor to healthy weight loss or management.

Amber Schaefer, MS, RDN, clinical nutrition lead and nutrition instructor at Mayo Clinic College of Medicine and Science, stated that protein consumption can enhance metabolism and lead to heightened satiety.

Further, protein helps to maintain this feeling of fullness for a longer duration.

Velazquez explained the role of each macronutrient in digestion and processing in the gastrointestinal tract, and highlighted how protein takes longer to break down, hence requiring more energy.

She also emphasized the crucial role that protein plays in maintaining overall body health while calorie intake is being reduced.

On deciding which sources to get protein from, consensus among experts is leaning towards plant-based options for their overall health benefits.

For instance, plant-based protein sources usually contain more fiber than animal proteins.

Velasquez pointed out the necessity of high fiber intake along with high protein for weight loss, stating that animal proteins may not offer as much fiber as plant-based ones.

As an example, a cup of black beans provides around 42 grams of protein and roughly 30 grams of fiber, while a half fillet of yellowtail fish offers around 43 grams of protein but zero fiber.

The higher fiber content in plant-based proteins enhances satiety, supports gut health, and facilitates regular bowel movements, according to Schaefer, thus aiding weight management.

Additionally, plant-based products are often healthier overall.

Although dependent on the specific type of protein and its preparation method, Schaefer noted that plant-based proteins usually have less saturated fats than animal proteins.

Overprocessed food products, which tend to carry extra calories from saturated fat, are not recommended.

Besides having more calories, processed foods can be harder on the body. Processed meats can contain nitrites, which have been linked with colorectal cancer, Velazquez noted.

More broadly, high intake of red meat—especially when processed—has been connected with increased chances for type 2 diabetes, heart disease, and mortality.

Consuming excessive amounts of animal-based products like steak or pork can cause stress to the body over time, Schaefer added.

On average, adults need about 0.8 grams of protein for each kilogram of body weight daily.

This implies that an individual weighing 150 pounds would require around 55 grams of protein each day.

Whether the goal is weight loss or health maintenance, obtaining the appropriate quantity of protein every day is recommended.

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.