7 Day Protein Diet

Protein builds strong muscles and can help you feel more satisfied on fewer calories — so why wouldn't you try a one-week protein diet? For those seven days, you won't eat only protein, but you will eat quite a lot of it. Therefore, it's important that you choose the healthiest sources.

People decide to try a high-protein diet meal plan for two main reasons: because they're trying to build muscle or because they want to lose weight — or both. Protein plays a central role in accomplishing both those goals.

For muscle-building, protein is king among the macronutrients. Comprised of essential amino acids that your body uses to build all the tissues of your body — muscle, skin, bones — getting enough of this macronutrient each day is crucial for achieving your strength and mass gains. Resistance training breaks down muscle fibers; in response to the stress, your body adapts, repairing the tissues and rebuilding them stronger and larger. Without adequate protein, it can't do this effectively.

The benefits of a seven-day protein diet for weight loss are manifold:

Satiety: Protein ingestion triggers the production of hormones involved in signaling fullness to the brain, according to an article published in September 2013 in the International Journal of Obesity. This makes it easier to stop eating sooner, which can help control calorie intake.

Metabolism: Your body expends more energy breaking down protein than it does the other macronutrients — carbohydrate and fat. According to a review article published in November 2014 in Nutrition & Metabolism, protein digestion temporarily boosts base metabolic rate by 15 to 30 percent. In contrast, the increase from carbohydrate is only 10 to 15 percent and from fat, it's just 0 to 3 percent.

Preserving muscle mass: Even without resistance training, your body is able to maintain muscle mass when it has enough protein. This is especially important when you're reducing your calories for weight loss, because your body may burn more lean muscle mass and stored carbohydrate than fat in the beginning, according to an article published in March 2014 in the Journal of the Academy of Nutrition and Dietetics.

Although building more muscle mass while dieting is ideal, maintaining it is necessary — muscle mass is more metabolically active than fat; the more you have, the more calories your body burns even while you're sleeping.

Read more: 8 Unconventional Protein Sources and Tips to Add More Protein to Your Diet

Your protein needs vary according to a few factors: your goals, your total calorie intake and your current body weight. General recommendations for adequate protein intake for healthy adults from the National Academies of Medicine are 46 grams daily for women and 56 grams daily for men. This is based on an estimated 0.8 grams of protein per kilogram of body weight for the average person.

But this is not going to be enough protein for a successful, high-protein diet. If you're putting your time in at the gym, you're likely going to need quite a bit more protein than the recommendation for the general population. According to both the Academy of Nutrition and Dietetics and the International Society of Sports Nutrition, regular exercisers who want to build and maintain muscle mass need between 1.2 and 2 grams of protein per kilogram of body weight each day.

If weight loss is your aim, research shows that somewhere in that same range is a good target. In a randomized, controlled trial published in Obesity Facts in June 2017, 118 adults with metabolic disorder followed either a standard protein diet, providing 0.8 grams per kilogram of body weight, or a high-protein diet meal plan providing 1.34 grams of protein per kilogram of body weight, for a period of six months.

Among those who adhered to the diets 75 percent of the time, those who ate more protein lost significantly more weight than those who ate the standard amount.

On a one-week protein diet, the sources matter just as much as the amount of the macronutrient they provide. There are many unhealthy foods that provide protein — such as pizza and hamburgers — but those aren't going to help you reach your goals and stay healthy at the same time.

If you're hitting it hard in the gym, you have a little more leeway with your calories. You might be able to indulge a little more in higher-calorie, high-protein foods, such as nuts and cheese. But if your goal is weight loss, you're going to have to be more judicious about the foods you pick, so you don't bust your calorie budget.

For either group, some of the highest-quality sources of protein include:

• Chicken breast
• Fish
• Shellfish
• Beans and peas
• Tofu, seitan and tempeh
• Eggs
• Nuts
• Dairy

Should you choose low-fat products? It depends. If you're really watching your calories, choosing low-fat milk and yogurt might be a better choice as they are slightly lower in calories. For example, there is about a 50-calorie difference between whole-milk Greek yogurt and low-fat Greek yogurt, according to USDA data.

The low-fat yogurt also has almost 2 extra grams of protein. If you eat a lot of dairy, it's also better to go with the low-fat version because of the saturated fat content. However, if you eat one or two servings a day, Harvard Health Publishing says there's no heart health risk.

Read more: 7 Popular Protein Myths Totally Busted by Science

Meat lovers won't like to hear that red meat should be eaten only occasionally in a healthy, high-protein diet. And processed meats like bacon, sausage, hot dogs and deli meats should be avoided because they increase the risk of heart disease and diabetes, reports Harvard.

If your goal is close to 100 grams of protein per day, you might wonder how in the world you are going to fit that much in your diet. Don't worry — it's easier than it seems. Aim to get an average of 25 to 35 grams of protein at each meal, and add snacks if necessary.

For a high-protein breakfast, a smoothie is a nutritious option that is great on the go. A high-quality protein powder without added sugar or some collagen powder can give you 10 to 20 grams of protein per scoop. You can then add some Greek yogurt, dairy or plant-based milk, fruits, vegetables and chia or flax seeds.

Of course, eggs are a go-to, high-protein breakfast food, but they're not just for breakfast. Egg sandwiches, omelets and scrambled eggs with lots of veggies make delicious quick lunches and dinners. Add some beans or tofu to your eggs for a plant-based protein boost.

Chicken and fish easily provide a good portion of a meal's protein quota in a 3.5-ounce serving. Pair either with sauteed spinach or broccoli and a serving of whole grains, all of which are nutritious sources of plant-based protein.

Then, depending on your calorie needs, you might also be able to fit in a snack or two. Nuts, nut butter and cheese are healthy, protein-packed options that will keep you satisfied until your next meal.