PROTEIN—HOW MUCH DOES A BODY NEED?
With all the protein-heavy diets plus protein bars, shakes and powders we’ve been offered lately, you’d think we didn’t get enough protein. However, recent studies show just the opposite. For example in the article Are you getting too much protein, Kristi Wempen, a Mayo Clinic registered dietitian nutritionist says, “Contrary to all the hype that everyone needs more protein, most Americans get twice as much as they need. Even athletes are often getting more protein than they need, without supplements, because their calorie requirements are higher. And with more food comes more protein.”
Along with carbohydrates (sugars) and fats (read my recent posts on these: Sugar—the Sweet & Bitter Truth and Fats—the Bad, the Good & the Questionable), protein is an essential macronutrient. It is found in all cells of the body—muscle, bone, skin, and hair. It is the essential building block of body tissue. Protein also makes up the enzymes that power many chemical reactions and the hemoglobin that carries oxygen in your blood. Proteins, through their DNA replication function, are polymer chains made of amino acids linked together by peptide bonds. During digestion, proteins are broken down in the stomach to smaller polypeptide chains via hydrochloric acid and protease actions
Here’s more information from the Harvard School of Public Health (Read article): Our bodies make amino acids in two different ways: Either from scratch, or by modifying others. A few amino acids (known as the essential amino acids) must come from food.
- Animal sources of protein tend to deliver all the amino acids we need.
- Other protein sources, such as fruits, vegetables, grains, nuts and seeds, lack one or more essential amino acids.
Vegetarians and vegans need to be aware of this. People who don’t eat meat, fish, poultry, eggs or dairy products need to eat a variety of protein-containing foods each day in order to get all the amino acids needed to make new protein.
“Although adequate protein throughout the day is necessary, extra strength training is what leads to muscle growth—not extra protein intake,” says Wempen. “You can’t build muscle without the exercise to go with it. The body can’t store protein, so once needs are met, any extra is used for energy or stored as fat. Excess calories from any source will be stored as fat in the body.”
Also, extra protein intake can lead to elevated blood lipids and heart disease, because many high-protein foods are high in total fat and saturated fat. Extra protein intake, which can tax the kidneys, poses an additional risk to individuals predisposed to kidney disease.
How much protein do you need?
The sources I read advised a person get from 10 to 35 percent (a rather wide range!) of their daily calories from protein. So, if your needs are 2,000 calories, that’s 200-700 calories from protein (50-175 grams). The recommended dietary allowance to prevent deficiency for an average sedentary adult is 0.8 grams per kilogram of body weight. For example, a person who weighs 75 kilograms (165 pounds) should consume 60 grams of protein per day.
“Once you hit around 50 years old, sarcopenia starts to set in, which means you start losing muscle mass as you age,” says Wempen. “To help prevent this and to maintain independence and quality of life, your protein needs increase to 1 to 1.2 grams per kilogram of body weight.”
People who exercise regularly also have higher needs, about 1.2-1.5 grams per kilogram. Those who lift weights regularly or are training for a running or cycling event need 1.2-1.7 grams per kilogram. Thus, active seniors probably need 1.5 or more grams per kilogram. Excessive protein intake would be more than 2 grams per kilogram of body weight each day.
What are good protein sources?
Wempen says the healthiest protein options are:
- Plant sources, such as soy, nuts, seeds, beans and lentils
- Lean meats, such as skinless, white-meat chicken or turkey, and lean cuts of beef or pork
- A variety of fish
- Eggs
- Low-fat dairy
“Meet your dietary protein needs with these whole foods as opposed to supplements,” she says. “Supplements are no more effective than food as long as energy intake is adequate for building lean mass. Manufactured foods don’t contain everything you need from food, nor do manufacturers know everything that should be in food. There may be compounds in real foods that we haven’t even discovered yet that may be beneficial for the body. So always be careful of foods created in a lab.”
When is the best time to consume protein?
Wempen recommends that you spread out protein consumption evenly throughout the day. On average, she says, people tend to get most of their protein during evening meals and the least at breakfast. Certain recent studies show moving some protein from supper to breakfast can help with weight management by decreasing hunger and cravings throughout the day.
General recommendations are to consume 15-25 grams of protein at meals and in the early recovery phase (anabolic window) — 45 minutes to one hour after a workout. Studies show higher intakes (more than 40 grams) are no more beneficial than the recommended 15-25 grams at one time.
If you still want to use a protein supplement, Wempen advises to look for: About 200 or less calories, 2 grams or less of saturated fat, no trans fat or partially hydrogenated oils, 5 grams of sugar or less.
Eating a banana, Greek yogurt and a hardboiled egg will get you 19 grams of protein on average. A three-ounce chicken breast with a half-cup rice and half-cup vegetables amounts to 25 grams of protein. The recommended 15-25 grams per meal or post-workout snack is attainable. If these were meals, you would want to balance them out by including all food groups: protein, grain, dairy, fruit and vegetables. Most people ─ even athletes ─ can reach their protein needs by including a serving of dairy at each meal and a piece of meat the size of a deck of cards at lunch and supper.
“Protein should be an accompaniment to fruits, vegetables and whole grains. It should not be the entire meal,” says Wempen. The flipside of eating too much protein means that your body will take the excess calories and store it as fat.