The amount of protein you need daily depends on multiple factors including age, muscle mass, activity level, and health status.
Protein is one of the most important nutrients for body composition and satiety.
The DRI for dietary protein is 0.8g per kg of bodyweight. However, this is a very modest intake level that might not be suitable for people who are more active and looking for an improved body composition.
Not all proteins are equal.
Dietary protein is essential for our bodies because they are broken down into amino acids that the body is not able to produce by itself. If you ever see a nutrition label with a decent protein content but writing that says "not a sufficient source of protein", it most likely means that the amino acid profile of the protein is not complete enough. For the most part, animal sources of protein tend to be the most complete, however, people following a vegetarian or vegan diet can successfully consume a complete amino acid profile by planning ahead and using supplements such as protein powder.
Protein & Weight Loss.
Protein is an important factor to consider when approaching a weight loss plan. It's even more important when the overall goal is fat loss.
To reinforce basic thermodynamics, you must still eat in a caloric deficit to lose weight. However, the composition of the weight loss can be heavily impacted by the type of foods you are eating.
Eating protein has its benefits when compared to fats and carbs because it has a higher thermic effect -- meaning it requires the body to burn more calories to digest.
In addition to the thermic effect, protein can help to control the calories going into your body by reducing your appetite and signaling satiety in the brain. The increased feeling of fullness from dietary protein can help to mitigate excessive snacking and prolong the amount of time you need before you feel ready for the next meal.
Protein, Muscle, & Strength.
Protein, more specifically amino acids, are the building blocks of muscle tissue. Although there are other factors such as carbohydrates, water - glycogen storage - that can greatly contribute to muscle size and appearance, dietary protein is arguably the most important nutrient needed for muscle.
Fat loss may be easier for someone with more muscle mass because their maintenance calories will be higher, meaning they will be able to eat more food even during a caloric deficit.
Protein is high in nitrogen content, and there must be a net positive nitrogen balance for muscles to be preserved and built. This is important because one of the biggest risks of weight loss is muscle loss.
In my personal experience, 1 gram of protein per pound of bodyweight has been sufficient to keep me on track with my fitness goals. Of course, depending on my exercise and NEAT level, I sometimes consume up to 1.5 grams of protein per pound of bodyweight.
The amount of protein that is right for everyone is different, so switching to a diet plan with mostly whole-foods and a relatively high protein can be a great start to starting your fitness journey. Just remember that not all protein, carbs, and fats are created equal so it is crucial that you pay attention to your nutrient sources.
Note: All calories and food sources are not the same so I personally recommend swaying away from IIFYM-type diets. Foods have much more complexity than simply carbs, fats, and proteins such as polyphenolic compounds that your body needs to maintain and improve your overall health.
**Disclaimer: This is not medical advice. Please consult your doctor before making dietary/lifestyle changes.**