Protein plays a critical role in weight loss and maintenance. By preserving and building lean muscle tissue and increasing the number of calories you burn during digestion, protein can help increase the amount of energy (in calories) you expend each day, promoting weight loss. It also helps to fight off hunger. Weight loss can be more difficult with an inadequate amount of protein.
Protein is found in the diet in two forms:
Animal proteins: Protein in the form of beef, poultry, fish, game meats, eggs, and cheese
Plant-based proteins: Protein from non-animal sources, such as tofu and other soy products, beans, and lentils
Before you get too wrapped up in eating all the protein you can get your hands on, remember the three types of protein: lean protein, medium-fat protein, and high-fat protein. Protein that contains a higher amount of fat also contains a higher number of calories per ounce. And because most high-fat protein also comes from animal sources, it’s usually in the form of unhealthy, saturated fats.
As you begin to add proteins to your meal plan, make sure to select lean proteins over the high-fat ones. Here’s the skinny on the differences:
Lean protein: Approximately 30–40 calories per ounce and 3 grams of fat or less per ounce
Medium-fat protein: Approximately 45–55 calories per ounce and 5 grams of fat per ounce
High-fat protein: Approximately 80–100 calories per ounce and 8 grams of fat per ounce
Because medium- and high-fat proteins contain a higher number of calories per ounce, consuming these types of proteins too often can slow your weight loss efforts. And, if they come from a source with an increased amount of saturated or trans fats, these proteins can increase inflammation, which may cause you to pack on more belly fat. So choosing lean proteins on a regular basis is essential to your success.
Protein: The hunger fighter
One of the main reasons you need to consume an adequate amount of protein when trying to lose or maintain a healthy body weight is that protein helps fight hunger. Unlike carbohydrates, which digest quickly, protein takes much longer to process.
This slow digestion helps you feel satisfied for a longer period of time. And if you aren’t feeling hungry, you’re probably not suffering from food cravings or eating too quickly, which are behaviors that can contribute to weight gain.
Visualize yourself eating a big bowl of enriched white flour pasta with nothing but tomato sauce on top. How long do you think this meal will keep you full? One hour? Two? Now picture yourself sitting down to eat out of the exact same bowl, but this time you fill it with pieces of grilled chicken instead.
You may not even be able to finish eating it, and, if you do, you’ll feel uncomfortably full for four hours or more.
Don’t go and stuff yourself with huge bowls of chicken. The moral of the story is this: For the same number of calories, protein keeps you feeling much more satisfied for a longer period of time. And this benefit prevents you from eating too-large portions of other foods, which can pack on the pounds. Include a source of lean protein at each meal to avoid becoming too hungry in between meals and snacks.
Don’t worry if you’re a vegetarian or vegan. Plant-based proteins work perfectly at helping to control appetite. So if you don’t consume any form of animal protein, adding a food like soy beans, lentils, or even tofu to your plate at each meal is important.
Protein: The metabolism booster
The most exciting benefit of eating protein is that it can help you burn more calories, therefore boosting your metabolism. Protein contains a high thermic effect. A thermic effect is the amount of energy (in calories) your body needs to burn in order to break down, digest, and metabolize a food.
Because protein contains a higher thermic effect than other macronutrients, it causes your body to burn more calories to digest it than if you ate a carbohydrate or fat.
Its high thermic effect isn’t the only way protein helps to boost metabolism. Your muscle tissue, which is made up largely of protein, is the most metabolically active tissue in your body. As a result, it burns many more calories than fat cells or other tissues.
When you start to lose weight, you can lose not just fat mass but muscle mass as well. If you lose too much muscle mass, your metabolism slows. Because muscle burns such a large number of calories, losing muscle means you burn fewer calories overall during the day, slowing your metabolism.
As a result, further weight loss and even weight maintenance may become difficult. Protein, however, contains an amino acid called leucine, which helps protect you against muscle losses while you’re losing weight. So be sure to consume an adequate amount of protein as you shed pounds.