Should I get my protein from animal or plant sources?

To maintain or gain muscle mass

If you are over age 50, you should increase protein intake to one gram per kilogram of your body weight just to maintain muscle mass, which declines with age.

If you're trying to gain muscle mass, a higher-protein diet can help support muscle repair and growth. When you exercise, muscle cells break down. Protein from food helps to repair the damage, ultimately strengthening muscles.

To lose weight

The value of high-protein diets for weight loss remains controversial. However, one meta-analysis found that a high-protein diet could lead to weight loss and prevent weight regain after weight loss. The authors note the need for future studies that follow patients for longer than one year for more insight into this issue.

Other benefits

One study found that eating plant-based protein was associated with lower odds of developing cognitive decline later in life. For every 5% of calories that came from plant protein instead of carbohydrates, researchers observed a 26% lower risk for developing dementia in study participants.

How much protein is too much?

The idea of an upper limit of protein intake is controversial. Some experts believe the recommended amounts are too low. Others believe we are overconsuming protein.

In general, the average person (not a body builder or an elite athlete) does not need high levels of protein and should not exceed 2 grams per kilogram; or about 125 grams per day for a 140-pound person.

A main concern with taking in too much protein is an overall dietary imbalance. Consuming excessive protein may lead to inadequate intake of carbohydrates and fats. It's important to maintain a well-rounded diet that includes a balance of all three macronutrients for overall health.

In addition, if you increase your protein intake without increasing physical activity, you may be taking in too many calories without expending enough, which could result in weight gain.