Protein is one of the three macronutrients that your body needs to function properly. It is made up of amino acids, which are the building blocks of your muscles, bones, skin, hair, enzymes, hormones, and antibodies. Protein also helps you feel full and satisfied, which can support weight management and prevent overeating.
But how much protein do you need, and what are the best sources of protein? In this article, we will answer these questions and compare animal and plant-based protein sources in terms of their quality, quantity, and health effects.
How Much Protein Do You Need?
The amount of protein you need depends on several factors, such as your age, sex, body weight, activity level, and health goals. The Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight per day for adults. This is the minimum amount of protein you need to meet your basic needs and prevent deficiency.
However, this amount may not be optimal for everyone, especially if you are physically active, pregnant, breastfeeding, recovering from illness or injury, or trying to build muscle or lose weight. In these cases, you may benefit from increasing your protein intake to 1.2-2.0 grams per kilogram of body weight per day.
To calculate your protein needs, you can use this simple formula:
Protein (grams) = Body weight (kilograms) x Protein factor
The protein factor is the number of grams of protein you need per kilogram of body weight. You can choose a protein factor based on your activity level and health goals, as shown in the table below.
| Activity level | Health goal | Protein factor |
|---|---|---|
| Sedentary | Maintain health | 0.8 |
| Moderate | Maintain health | 1.0 |
| Active | Maintain health | 1.2 |
| Very active | Maintain health | 1.4 |
| Athlete | Build muscle | 1.6 |
| Athlete | Lose fat | 2.0 |
For example, if you weigh 70 kilograms and you are moderately active, your protein needs are:
Protein (grams) = 70 x 1.0 = 70 grams per day
It is important to note that these are general guidelines and your individual protein needs may vary depending on your specific situation. You can consult a registered dietitian or a doctor for more personalized advice.
What Are the Best Sources of Protein?
Protein can be found in both animal and plant-based foods, but not all protein sources are equal. There are two main criteria to evaluate the quality of protein sources: the amino acid profile and the digestibility.
Amino Acid Profile
Amino acids are the building blocks of protein, and there are 20 different amino acids that your body needs. Nine of these are essential, meaning that your body cannot make them and you need to get them from your diet. The other 11 are non-essential, meaning that your body can make them from other amino acids.
The amino acid profile of a protein source refers to the amount and proportion of each amino acid it contains. A protein source that has all nine essential amino acids in sufficient amounts is called a complete protein. A protein source that is missing or low in one or more essential amino acids is called an incomplete protein.
Animal-based protein sources, such as meat, poultry, fish, eggs, and dairy, are generally complete proteins, meaning that they provide all the essential amino acids your body needs. Plant-based protein sources, such as beans, lentils, nuts, seeds, and grains, are generally incomplete proteins, meaning that they lack or have low amounts of one or more essential amino acids.
However, this does not mean that plant-based protein sources are inferior or inadequate. You can still get all the essential amino acids you need by eating a variety of plant-based protein sources throughout the day or by combining complementary plant-based protein sources in the same meal. Complementary protein sources are those that have different amino acid profiles that complement each other, such as beans and rice, hummus and pita bread, or peanut butter and toast.
Digestibility
Digestibility refers to how well your body can absorb and use the protein you eat. The digestibility of a protein source depends on several factors, such as the type and amount of protein, the presence of other nutrients, the processing and cooking methods, and your individual digestive health.
Animal-based protein sources are generally more digestible than plant-based protein sources, meaning that your body can absorb and use more of the protein they provide. This is because animal-based protein sources have a similar amino acid profile to your body’s own proteins, and they have less anti-nutrients, such as fiber, phytates, and lectins, that can interfere with protein digestion and absorption.
Plant-based protein sources are generally less digestible than animal-based protein sources, meaning that your body can absorb and use less of the protein they provide. This is because plant-based protein sources have a different amino acid profile from your body’s own proteins, and they have more anti-nutrients, such as fiber, phytates, and lectins, that can interfere with protein digestion and absorption.
However, this does not mean that plant-based protein sources are ineffective or insufficient. You can still get enough protein from plant-based sources by eating more of them, choosing high-quality and minimally processed ones, and combining them with other nutrients, such as vitamin C, that can enhance protein digestion and absorption.
What Are the Health Effects of Animal and Plant-Based Protein Sources?
Protein sources are not only different in terms of their quality and quantity, but also in terms of their health effects. Animal and plant-based protein sources have different impacts on your health, depending on their type, amount, and frequency of consumption.
Animal-Based Protein Sources
Animal-based protein sources are rich in protein, but they also contain other nutrients, such as fat, cholesterol, iron, zinc, calcium, and vitamin B12, that can have both positive and negative effects on your health.
On the positive side, animal-based protein sources can help you meet your protein needs, as well as provide other essential nutrients that are important for your growth, development, immunity, and metabolism. Animal-based protein sources, especially lean and low-fat ones, can also support your muscle mass, strength, and performance, as well as your satiety and weight management.
On the negative side, animal-based protein sources can also increase your intake of saturated fat, cholesterol, sodium, and environmental contaminants, such as hormones, antibiotics, and pesticides, that can have adverse effects on your health. Animal-based protein sources, especially red and processed meats, can also increase your risk of chronic diseases, such as cardiovascular disease, type 2 diabetes, and some cancers, especially if you consume them in large amounts and frequently.
Therefore, it is important to choose animal-based protein sources wisely, and to moderate your intake of them. The World Health Organization (WHO) recommends limiting your intake of red meat to less than 500 grams per week, and avoiding processed meat as much as possible. The American Heart Association (AHA) recommends limiting your intake of saturated fat to less than 5-6% of your total calories, and choosing lean and low-fat animal-based protein sources, such as skinless poultry, fish, eggs, and low-fat dairy.
Plant-Based Protein Sources
Plant-based protein sources are not only rich in protein, but they also contain other nutrients, such as fiber, antioxidants, phytochemicals, vitamins, and minerals, that can have beneficial effects on your health.
On the positive side, plant-based protein sources can help you meet your protein needs, as well as provide other essential nutrients that are important for your health and well-being. Plant-based protein sources, especially legumes, nuts, seeds, and soy, can also support your heart health, blood sugar control, cholesterol levels, and inflammation, as well as reduce your risk of chronic diseases, such as cardiovascular disease, type 2 diabetes, and some cancers .
On the negative side, plant-based protein sources can also have some drawbacks, such as being less digestible, less complete, and less bioavailable than animal-based protein sources, as well as containing some anti-nutrients, such as phytates, lectins, and oxalates, that can impair the absorption of some minerals, such as iron, zinc, and calcium.
Therefore, it is important to choose plant-based protein sources carefully, and to optimize your intake of them. You can do this by eating a variety of plant-based protein sources throughout the day, combining complementary plant-based protein sources in the same meal, choosing high-quality and minimally processed plant-based protein sources, and enhancing the absorption of plant-based protein and minerals by soaking, sprouting, fermenting, or cooking them, and by consuming them with other nutrients, such as vitamin C, that can boost their bioavailability.
Conclusion
Protein is an essential nutrient that your body needs for multiple functions and benefits. You can get protein from both animal and plant-based sources, but they differ in terms of their quality, quantity, and health effects. Animal-based protein sources are generally more digestible, complete, and bioavailable than plant-based protein sources, but they also contain more saturated fat, cholesterol, sodium, and environmental contaminants, and can increase your risk of chronic diseases. Plant-based protein sources are generally less digestible, complete, and bioavailable than animal-based protein sources, but they also contain more fiber, antioxidants, phytochemicals, vitamins, and minerals, and can reduce your risk