Protein: How Much You Need, Best Sources, and What Happens If You Eat Too Much
- Melissa Nichols
- Jul 27
- 4 min read
Updated: 6 days ago
Protein is more than a fitness buzzword. It's a vital nutrient that your body needs every single day to function correctly. From muscle repair and immune defense to hormone production and metabolism, protein plays a role in nearly every part of your health.
But how much do you need? What kind is best for your lifestyle? And can you overeat?
Let's break it down.
Understanding Protein: The Essential Nutrient
Protein is a macronutrient that, when broken down or digested, produces amino acids. The nine essential amino acids help to grow and repair tissues, make hormones, provide energy, maintain healthy skin and nails, and build muscle.
Types of Proteins
Complete proteins contain all nine essential amino acids and include:
Beef
Poultry
Fish
Eggs
Dairy products
Soy
Quinoa
Buckwheat
Pistachios
Incomplete proteins contain some amino acids but not all nine. They need to be combined with other incomplete proteins to obtain all nine essential amino acids. Examples include:
Nuts
Seeds
Beans
Brown rice
Whole-wheat bread
Since vegans and vegetarians don't eat meat, they need to consume soy and various types of incomplete proteins to ensure they get all nine essential amino acids. An example of combining incomplete proteins is to eat a grain and a legume together. Both are incomplete, but together they contain all nine essential amino acids.
How Much Protein Do You Need?
Protein needs vary based on age, gender, activity level, and health goals. The Recommended Dietary Allowance (RDA) for protein is:
Group | RDA per kg of body weight |
Adult Women (sedentary) | 0.8 g x body weight in kg |
Adult Men (sedentary) | 0.8 g x body weight in kg |
Active Adults | 1.1–1.5 g x body weight in kg |
Older Adults (40+) | 1.0–1.2 g x body weight in kg |
Adults who exercise regularly | 1.1–1.5 g x body weight in kg |
Adults (65+) with acute or chronic illness | 1.2-1.5 g x body weight in kg |
Adults (65+) with severe illness, injury, or malnutrition | 2.0 g x body weight in kg |
Spacing protein intake throughout the day, rather than consuming most of it at one meal, may be more effective for muscle protein synthesis. The recommendation is 2-3 meals a day with 25-30 grams of protein per meal. These protein levels per meal would vary based on your protein needs.
The Importance of Protein as You Age
Once you're between the ages of 40 and 50, sarcopenia begins to develop. This condition is characterized by the loss of muscle mass that occurs with age. To prevent this and maintain independence and quality of life, protein intake needs to increase to approximately 1-1.2 grams per kilogram.
People who exercise regularly also have higher protein needs, ranging from about 1.1 to 1.5 grams per kilogram. If you regularly lift weights or are training for a running or cycling event, you need 1.2-1.7 grams per kilogram.
The PROT-AGE Study Group is an international consortium of experts dedicated to developing evidence-based recommendations for optimal dietary protein intake in older adults. They created the guidelines for protein intake described above for adults aged 65 and over.
Best Types of Protein by Diet Type
Whether you're an omnivore, vegetarian, or vegan, quality and variety matter.
Omnivores
Best protein sources:
Eggs – complete protein, easy to digest
Chicken, turkey, lean beef – rich in all essential amino acids
Fish – especially fatty fish like salmon (bonus: omega-3s)
Dairy – Greek yogurt, cottage cheese, milk
Vegetarians
Best protein sources:
Eggs and dairy – if included
Legumes – lentils, chickpeas, black beans
Tofu and tempeh
Quinoa – a complete plant-based protein
Vegans
Best protein sources:
Lentils and beans
Tofu, tempeh, edamame
Hemp seeds, chia seeds, flaxseeds
Pea and rice protein powders
Spirulina and nutritional yeast
Looking for the right protein powder? Check out the Resourcing section of my website that breaks this down. www.reformingyou.com
Can You Eat Too Much Protein?
Yes, but it's not common if you're eating balanced meals.
What Happens if You Overdo It?
Kidney strain – primarily a concern for those with pre-existing kidney conditions.
Dehydration – metabolizing protein requires more water.
Nutrient imbalance – high-protein diets can sometimes crowd out fiber and essential vitamins if not well-planned.
Note: Most healthy individuals can safely consume up to 2.2g/kg of body weight in protein without issues.
High-Protein Foods to Eat Regularly
Here's how to efficiently work protein into every meal:
Breakfast
Greek yogurt (17–20g per serving)
Eggs (6g each)
Protein smoothie with protein powder, seeds, and nut butter
Lunch
Lentil or chickpea salad (15–18g per cup)
Quinoa bowl with tofu and veggies
Turkey sandwich on whole-grain bread
Dinner
Baked salmon (22–25g per 3oz)
Stir-fry with tempeh and brown rice
Black bean tacos with avocado and veggies
Snacks
Cottage cheese (13g per ½ cup)
Hard-boiled eggs
Hummus with raw veggies
Protein bars (look for 10–20g per bar with clean ingredients)
The Bottom Line on Protein Intake
Protein isn't just for bodybuilders. It's essential at every stage of life, especially as we age, manage weight, or work to balance hormones.
Make it a goal to include high-quality protein at each meal. Whether you're plant-based or omnivorous, there are plenty of nutrient-dense options to support your body, energy, and long-term health.
Need help building a meal plan that meets your protein needs while supporting your health goals? Let's chat. Reforming You offers personalized health coaching designed to fit your lifestyle.