How Much Protein Per Day? The Latest Science Explained

How much protein per day is ideal? Here's the latest scientific knowledge on optimal protein intake for muscle building, weight loss, and more.

3 MIN READ — 03/05/2025

Proteins are the building blocks of life—but how much do you really need to stay healthy and fit? Whether you’re aiming to build muscle, lose weight, or simply maintain your health, your daily protein intake plays a crucial role. However, the optimal amount varies from person to person. Learn how to tailor your diet to meet your goals and ensure your protein intake matches your lifestyle.

What Is Protein and How Does It Work in the Body?

Proteins are essential nutrients for the human body and play a key role in many bodily processes. They help build and repair cells and tissues and are made up of amino acids, which serve as building blocks for various structures. Skin, hair, and muscles rely heavily on adequate protein intake. While the body can produce some amino acids, we must obtain the essential amino acids through food.

Essential Amino Acids:

  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine

Non-essential Amino Acids:

  • Alanine
  • Arginine
  • Aspartic Acid
  • Asparagine
  • Cysteine
  • Glutamine
  • Glutamic Acid
  • Glycine
  • Histidine
  • Proline
  • Serine
  • Tyrosine (essential for children)

Protein Per Kg: How to Calculate Your Optimal Intake

The German Nutrition Society (DGE) recommends a daily protein intake of 0.8g per kilogram of body weight. This guideline provides a baseline, but individual needs may vary, especially for those who are physically active. For ambitious amateur athletes and professional athletes, the DGE recommends 1.2 to 2.0g of protein per kilogram of body weight daily. In such cases, supplements can help meet these higher protein requirements to achieve optimal results.

How Much Protein per Day for Weight Loss?

If you're aiming to lose weight, reducing your protein intake is a common mistake you should avoid. Your protein needs remain the same, whether you're looking to lose weight or maintain it. Reducing protein too much can result in muscle loss—something you want to avoid during weight loss. For individuals who are underweight or overweight, the recommended protein intake should always be calculated based on a normal weight as there are no specific reference values for these conditions.

How Much Protein per Day for Muscle Building, Health, and Body Composition?

For maintaining normal bodily functions and a healthy body composition, the DGE guidelines are generally sufficient. However, if your goal is to build muscle and achieve rapid progress, your protein intake can be higher. That said, you don’t need to overdo it—muscles are only about 20% protein, the rest is mainly water. If your weekly training exceeds five hours, it may be worth increasing your protein intake and considering supplements to meet your needs.

For general health and fitness, it's also important to control body fat and increase muscle mass. For women aged 20 to 79, the recommended body fat percentage is 21 to 35%, while for men it should be between 8 and 24%.

Protein Sources: Which Foods Provide the Best Amount?

Here are some of the most important plant-based protein sources:

  • Grains and pseudograins (e.g., rice, oats, and bread)
  • Legumes like soy, lentils, and beans
  • Rapeseed
  • Nuts

And these are some key animal-based protein sources:

  • Game
  • Tuna
  • Mature cheese
  • Low-fat milk
  • Yoghurt
  • Eggs

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Micronutrients for Protein Metabolism

If you want to support protein metabolism, micronutrients play an important role. For example, biotin, zinc, and chromium contribute to the normal metabolism of macronutrients, including protein. Molybdenum helps metabolise sulphur-containing amino acids, and vitamin B6 is also crucial for a normal protein metabolism. It's important to ensure your diet includes these micronutrients.

Protein and Collagen: Why Your Body Needs Protein for Collagen Production

Collagen production relies on two key amino acids—proline and glycine. These are among the building blocks that make up proteins. If you want your body to produce more collagen, you need to focus on a protein-rich diet. If you're unable to get enough protein from meals, supplements can be useful, especially during periods of intense training.

At a Glance

  • 01.

    The German Nutrition Society recommends 0.8g of protein per kilogram of body weight daily, though athletes and active individuals may require up to 2.0g for muscle building and optimal performance.

  • 02.

    Adequate protein intake is crucial for maintaining muscle mass during weight loss. Reducing protein can lead to muscle loss, something you want to avoid when dieting.

  • 03.

    Both plant and animal protein sources provide essential amino acids. Additionally, micronutrients such as biotin and zinc play a critical role in supporting protein metabolism and keeping the body in balance.

Article Sources

Food supplements are not a substitute for a balanced and varied diet and a healthy lifestyle. Do not exceed the indicated daily intake. Keep out of reach of children. Please inform and consult your doctor before consuming this product. Not suitable for children and adolescents under 18 years, pregnant or breastfeeding women. Refrain from taking other food supplements containing zinc. Persons taking anticoagulant medication should seek medical advice before consuming vitamin K-containing supplements.

* Genuine reviews from customers who received a review link after purchase.

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º Food Supplement. In combination with a healthy diet and exercise.

⟡ Survey on the awareness of multi-nutrient powders with 211 consumers aged 18 to 49 in Germany, 09/24.

↡ Survey of 527 AG1 customers after 12+ days of use, 2024. The survey was conducted on a previous version of AG1’s continually evolving formulation. The survey results can be transferred to the current version of the formula due to no or scientifically negligible changes in supporting nutrients. Vitamins C, B6, B12, riboflavin, niacin, pantothenic acid, and folate help reduce tiredness and fatigue. Pantothenic acid supports mental performance. Calcium supports normal digestive enzyme function, while biotin maintains normal mucous membranes, such as the gut lining.

◊ Comparison (2025) with individual supplements in comparable amounts that are typically sold at retail: vitamin B complex, vitamin A, vitamin C, vitamin E, bacterial cultures, zinc, magnesium, calcium, selenium, chromium, manganese, molybdenum, coenzyme Q10, greens powders (from sea algae such as spirulina, barley leaf, wheatgrass, dandelion, spinach powder, etc.), mushroom supplements (reishi, shiitake).

‡ Survey of 144 verified customers from 12 European countries who have been taking AG1 for an average of 9 days.


Research Studies
a. In a triple-blind, randomised, placebo-controlled parallel-designed clinical trial evaluating nutrient biomarkers and microbiome shifts in 105 healthy adults ages 20-59 over the course of 12 weeks.
b. In a double-blind, randomised, placebo-controlled 2-week cross-over clinical trial assessing microbiome shifts in 20 active adults ages 19-37.
c. In a double-blind, randomised, placebo-controlled 2-week cross-over clinical trial assessing microbiome shifts of 24 healthy adults with occasional GI distress ages 26-59.
d. In a double-blind, randomised, placebo-controlled cross-over clinical trial assessing bioavailability in 16 healthy adults ages 18-42 over the course of 8 hours.
The studies were conducted on a similar version of AG1's continually evolving formulation. The transferability of the study results is ensured because of comparable ingredients and amounts.

Immune System

1: With vitamins A, C, B6 and B12 as well as folate, zinc, copper and selenium, AG1 contributes to the normal function of the immune system. Vitamin C contributes to maintain the normal function of the immune system during and after intense physical exercise.

Energy; Metabolism

2: Vitamins C, B6, B12, riboflavin, niacin, pantothenic acid and magnesium contribute to normal energy-yielding metabolism and to the reduction of tiredness and fatigue. With vitamins C, B6, B12, as well as thiamine, riboflavin, niacin, biotin, pantothenic acid, calcium, phosphorus, copper and manganese, AG1 contributes to normal energy-yielding metabolism. Magnesium contributes to electrolyte balance. Biotin, zinc and chromium contribute to normal macronutrient metabolism.

Cell Protection

3: With vitamins E and C as well as riboflavin, zinc, copper and selenium, AG1 contributes to the protection of cells from oxidative stress. Phosphorus contributes to normal function of cell membranes. Folate, Vitamin B6 and B12 contribute to normal homocysteine metabolism.

Mental Performance; Psychological Function; Nervous System

4: With pantothenic acid, AG1 contributes to normal mental performance. Zinc contributes to normal cognitive function. With vitamins C, B6, B12, B1, B3 and B7 AG1 contributes to normal psychological function and to normal functioning of the nervous system. Calcium contributes to normal neurotransmission.

Skin, Hair & Nails

5: With vitamins A, as well as riboflavin, niacin, biotin and zinc, AG1 contributes to the maintenance of normal skin. Vitamin C contributes to normal collagen formation for the normal function of skin. Vitamin B7, zinc and selenium contribute to the maintenance of normal hair. Zinc and selenium contribute to the maintenance of normal nails.

Hormonal System

6: With vitamin B6, AG1 contributes to the regulation of hormonal activity. Zinc contributes to the maintenance of normal testosterone levels in the blood. Selenium contributes to the normal thyroid function. With chromium, AG1 contributes to the maintenance of normal blood glucose levels.

Digestion

7: Calcium contributes to the normal function of digestive enzymes. Biotin AG1 contributes to the maintenance of normal mucous membranes (e.g. intestinal mucosa).

Muscles

8: With calcium and magnesium, AG1 contributes to normal muscle function.