Protein 101

Eating the right amount of protein is an important part of maintaining a healthy weight. And it’s no secret that maintaining a healthy weight can help lower your cancer risk.

But protein is often misunderstood and there are many myths surrounding it. We asked Joan Elizondo, senior clinical dietitian, to answer some common questions about protein. 

What is protein? Why is it so important?

Proteins are large molecules made of amino acids that help us build and repair muscle. It’s essential for the body to function properly. If we don’t get enough, our bodies will use what we already have and break down our muscle.

If you’re not getting enough protein, you may get tired easily. You also may lack the strength necessary to exercise -- a key factor in maintaining a healthy lifestyle.

What is a complete protein?

Protein is made up of chains of amino acids.

There are 20 different amino acids. Of those, the body can’t make nine on its own. These are known as essential amino acids.

A food is considered a complete protein if it contains equal parts of all nine essential amino acids.

Animal proteins, like meat, fish, eggs and dairy, are all considered complete proteins because they contain all the essential amino acids.

So, is animal protein better for you than plant protein?

Not necessarily. Some plant-based proteins, like quinoa, buckwheat, hempseed and soy, are complete proteins.

You also have the option of combining two incomplete plant-based proteins, like rice and beans, to create a complete protein. You don’t even have to eat them in the same meal, just in the same day.

At MD Anderson, we recommend a mostly plant-based diet. That means, two-thirds of your plate should be plant-based foods and the other third or less can be animal-based food.

How much protein should you have?

The average person should have 0.8 grams of protein per kilogram of body weight. (To convert your weight from pounds to kilograms, divide your weight in pounds by 2.2.) So someone who weighs 150 lbs should have 54.6 grams of protein each day.

Depending on your lifestyle, you may need more protein. Athletes, body builders, pregnant women, cancer patients and those preparing for surgery typically need more. Talk to your health care provider or dietitian about your protein needs. 

Is it possible to eat too much protein?

Whenever you start focusing on one food group, you’re more likely to forget about the others and miss out on the important nutrients your body needs from fruit, vegetables and whole grains. Eating too much protein can lead to unwanted weight gain, which can add to your cancer risk.

Does it matter what time of day you consume protein?  

It’s important to eat it throughout the day. Your body needs about 30 grams of protein every three to four hours to build and repair muscle.

Often, many of us don’t get the protein we need early in the morning. Many common breakfast foods, like cereal or bagels, contain more carbohydrates than protein. By eating a little bit of protein with each meal starting with breakfast, we can balance our energy and are more likely to stay satisfied for longer periods of time. 

Request an appointment at MD Anderson's Lyda Hill Cancer Prevention Center online or call 877-632-6789.

View a printable version of our Protein 101 Guide.