What Type and How Much Protein Your Body Needs According to Your Age and Lifestyle


The most concentrated forms of dietary protein are animal proteins, but that does not mean that they are the ones that our body absorbs more efficiently and, above all, after having fasted for at least 16-18 hours or exercised on an empty stomach.

Today we will review why protein is crucial for our body and what type of protein works best for you based on your activities and time of day.


Why do we need protein in our body?

There are many types of molecular proteins that contain different combinations of the 20 known amino acids. To date, around 10,000 different proteins have been identified in the human genome, but there are more, many more.

Protein is involved in virtually every function in the body. It builds and repairs all types of tissue, produces enzymes, hormones, and other substances, and it is also a component of bones, bones, teeth, skin, blood, nails, and hair.

The antibodies our bodies use to fight infection and prevent disease are made from proteins, as well as the enzymes that code our DNA to make new molecules.

Proteins also function as a communication system between cells, organs and tissues; and transport atoms and molecules throughout the body.

The ultimate reason why we need Protein is to preserve our muscle mass as we age as it is crucial for our health. Our muscle mass is expressed in every activity we do from standing up, walking, lifting objects, sitting down. Our muscle mass and strength take on immense value when we cannot perform these daily activities, having to rely on the support of other people, objects, or machines to perform them for us.

The decline in muscle mass leads to sarcopenia, a type of muscle loss (muscle atrophy) that occurs with aging and/or immobility. This is characterized by degenerative loss of skeletal muscle mass, its quality and strength.

The good news is that people over 30, 40, 60 and even 70 years old can recover a little muscle, strength, but above all, restore functionality to the body, thanks to strength training or weight exercises. The key to muscle recovery is in the strength and power to perform at least daily activities.

Strength training goes hand in hand with nutrition, specifically, adequate protein intake. But it is important to understand that there is a difference between absorption and utilization (synthesis).


Protein Absorption and Synthesis

The absorption of protein depends largely on the state of your intestinal flora to absorb this and other nutrients, as well as the ability of the liver to deaminate a food, although, sometimes, the kidneys also take care of it.

Aside from good gut health, efficient protein absorption also depends on the catalyst, that is, the stimulus in your body that makes it need to absorb this protein. The body is simply going to absorb the amount it needs of what it is requiring.

According to Professor Stuart Phillips, Director of the Physical Activity Center for Excellence, Center for Nutrition, Exercise and Health Research, Department of Kinesiology at McMaster University, Canada, in a talk on Building Muscle with Resistance Exercise and Reassessing Protein Intake, indicates that the minimum protein intake for an adult person is 1.2 grams per kilogram of body weight; while athletes and the elderly can benefit from up to 1.6 grams per kilogram of body weight.

This is, according to Phillips because,

“As we get a little older, people's appetite decreases. People tend to gravitate towards different ways of eating, and protein actually makes up a much smaller percentage of the diet. So, by the time you think you need more protein and want to support lean muscle mass as you age, most people's protein intake is actually declining to levels where it becomes limiting to the amount of muscle they can build.”

As we age, muscle maintenance and mobility are in part promoted by protein intake. At present, certain social groups must specifically pay attention to adequate consumption:

  • Overweight and sedentary people who can benefit from caloric restriction (0.8 g per kg of weight).
  • Young and healthy, active people who need a higher protein intake (1.2 g. per Kg of weight),
  • Athletes and older people who must prevent and/or combat sarcopenia who need even more protein (1.6g per kg of weight).


Digestion Rate Can Affect Protein Utilization

Just as important as getting an adequate amount of protein is that it be absorbed efficiently. Consuming protein does not mean that you are absorbing 100% of it. There is a limit to the amount of protein the body can absorb in one sitting; and the maximum rate at which a “fast absorbing” protein can be absorbed is 8-10 grams per hour. That is, you might have to space protein intake at least in two meals unless you are doing the protocol of only one meal a day.

Several studies have been published using different types of protein such as whey, soy, pea isolates, egg, casein and beef, the results have shown that certain types of protein are absorbed better and faster than others.

According to a study published by the Journal of the International Society of Sports Nutrition, to maximize anabolism, protein should be consumed with a target intake of 0.4 g/kg/meal in a minimum of four meals to reach a minimum of 1.6 g/kg/day. Using the maximum daily intake of 2.2 g/kg/day reported in the literature spread over the same four meals, a maximum of 0.55 g/kg/meal would be needed.


How to divide my protein intake throughout the day or better, what is the ideal time to consume protein?

Phillips says that the only people who really need to be vigilant about timing their protein intake are athletes aiming for a competition or an Olympic medal, the rest of us mortals can break the fast with protein, meaning that their first meal be when you consume the highest and best quality protein.

At the same time, other studies on protein consumption indicate that the human body is not designed to absorb more than 20-25 grams of protein per meal, unless you have just finished a strong workout or from a lot of activity; the rest of that Protein can go to other parts of the body or will be converted to urea.

The body will simply absorb only what it needs to meet its needs and will try to eliminate what is left over. In this sense, it is not worth consuming exaggerated amounts of protein or protein shakes, unless you have just finished a strong workout or are being physically active, makes more sense to adhere to the parameters mentioned, according to your lifestyle.


Fast-absorbing proteins and other options

A fast-absorbing protein is one that is absorbed within 2 hours. Intermediate-absorbing protein takes 3 to 3 ½ hours to digest and slow-absorbing protein takes 4 hours or more.

Whey protein: Fast absorption

  Isolated pea protein: Intermediate absorption


Hard boiled eggs: Intermediate absorption


Red meat: Intermediate but slower absorption than eggs or isolated pea protein.


Bone broth: Intermediate absorption, but being like shredded meat, it's closer to being a fast-absorbing protein. The same happens with other minced animal proteins.


Amino acid complex: In general, quickly absorbed, although it depends on the brand and if it is slow-releasetype.

Casein (dairy): Slow absorption

Casein, present in dairy products, although it can have an inflammatory effect on some people, is a slowly absorbed protein that is best consumed with your last meal as it protects the body from protein degradation and oxidation of the amino acid leucine.



A fast absorption protein immediately at the end of training, to provide the necessary "building blocks" to rebuild tissue and replenish. However, once that protein is absorbed, the body will not have available protein to replenish with and will be exposed to not being able to rebuild muscle.

Keep in mind that the metabolism is active for up to 17 hours after strength training; and about 48-72 hours during which it will be using amino acids for muscle recovery and muscle protein synthesis. So for the hours that follow, it is advisable a more stable or intermediate absorption protein.

Vegetarians and those with very active metabolisms that need to maintain their muscle mass can benefit from an amino acid complex to support muscle rebuilding as the hours go by after training, or even during training where you are not consuming any food.

Products based on casein such as dairy products and that are slowly absorbed are best left for later meals or the last meal of the day.

Note that the speed of absorption of protein will be affected if it is consumed with fiber or fat, since adding nutrients would slow down the absorption process.

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