What’s the Deal with Protein and Weight Loss?

Published: June 24th, 2013   |   Author: Jackie Gentilesco

Seek leaner sources to support a healthy weight.

When you think “protein” you may instantly think of infomercial supplements, power shakes, and juicy steaks, but they aren't the best ways to get this vital nutrient. Eating the right proteins can help you lose weight and maintain lean muscle mass.
Why You Need Protein
Protein is an essential nutrient for cell growth and maintenance, disease prevention, satiety, and various functions of the body. “While it is easy to associate it with muscle growth in athletes, an adequate supply of quality protein in the diet is also important for maintaining the muscle mass we already have. Protein is not just for athletes,” says Shane M. Rutherfurd, MSc, PhD, senior research officer at Riddet Institute in New Zealand and a leading researcher on protein. 
Protein also keeps our muscles toned as we lose weight, says Tina Marinaccio, RD, CPT, and owner of Health Dynamics in Morristown, New Jersey. “When you lose weight, you lose lean body mass, so following a low-fat, high-protein diet during your weight loss phase can help you preserve more of your muscle mass.” Because protein supports muscle density, it’s also especially important to eat it as we age, Marinaccio and Rutherfurd agree.
How It Curbs Cravings
Protein takes two times longer to digest than carbohydrates, which break down in an hour or so, Marinaccio says. “Protein is less energy dense than fat and is more satiating than carbohydrates and possibly fat,” Rutherfurd says. Plus, it keeps hunger hormones in control, Marinaccio says. If you aim for a diet of 40% whole grains, 30% lean protein, and 30% healthy fats (anything with omega-3 fatty acids), you are sure to feel satisfied from your meals, she says.
How Much Do You Need?
Generally, Americans get sufficient amounts of protein. According to the CDC, women ages 19-70+ should have 46 grams of protein daily, preferably from a lean source (see list below). Men in the same age group should get 56 grams of protein daily.
If you’re trying to lose weight, Marinaccio recommends increasing your lean protein intake to 90-100 grams per day and following a 1,200-1,400 calorie diet (measurements based on a 140-pound woman). 
Where to Get Lean Protein
Not all proteins are created equal. Look for sources that are closest to their natural form, and skip processed foods, Marinaccio says. While meat, dairy and eggs are “complete” proteins, meaning they contain the proper amount of amino acids to help protein carry out its various functions, they’re not always the healthiest because of high fat content.
Instead, Marinaccio suggests focusing on plant-based proteins. While most plant proteins are incomplete (meaning they should be combined with other “incompletes” to be a sturdy source of protein), it’s nothing to stress over. A varied diet is all you need. “You don't have to worry about not getting the right number of amino acids in a single food, just get a variety of foods, which could include plant protein sources, and your body is smart enough to sort out the rest!” Marinaccio says.
Smart Sources
Try these healthy choices from Marinaccio:

  • Soy products, such as firm tofu (1 cup, 40g protein) or edamame (1 cup, 22g protein) “Soybeans are superior to other beans in that they already contain a good amino acid balance,” Marinaccio says.
  • Yogurt—especially Greek yogurt, which is higher in protein than other yogurts (6 ounces, 18g protein)
  • Plant-based proteins, such as spirulina or legumes (e.g. 1 cup black beans, 15g protein)
  • Any kind of fish (e.g. 1 ounce of smoked salmon, 7g protein)
  • Egg whites (2 eggs, 7g protein)
  • Meat that’s at least 93% lean (e.g. 1 ounce pork tenderloin, 7g protein)
  • Low-fat, low-sodium cheese (1 ounce, 7g protein)
  • Textured vegetable protein aka “TVP” (1/4 cup, 7g protein)
  • Chopped nuts, which can be sprinkled onto cereal or yogurt (1 ounce, 6g protein)
  • Nut butters, but watch portion size (1 tablespoon, 4g protein).

As for proteins to avoid, skip protein shakes, fatty meats, and frozen meals which can be high in sugar, saturated fat, salt, and fillers. 
The Bottom Line
Protein is an important part of supporting a healthy body, and eating a well-rounded diet with lean protein sources can help you lose weight, improve satiety at meals, and support vital functions. 
Related Links
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