What type and how much protein do you really need based on 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 are absorbed most efficiently, especially after having fasted for at least 16-18 hours or having exercised on an empty stomach.

Today we will review why protein is necessary and what type of protein works best for you depending 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 amino acids that we know.  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 is also a component of bones, teeth, skin, blood, nails and hair.

The antibodies our bodies use to fight infections and prevent disease are made of proteins, as are the enzymes our DNA uses to make new molecules.

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

The final reason is that we need to preserve our muscle mass as we age as it is crucial to our health.  Our muscle mass is expressed in every activity we do, from standing up, walking, lifting objects, sitting.  Our muscle mass and strength take on immense value when we are unable to perform these daily activities, needing the support of other people, objects, or machines to do 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. It is characterized by degenerative loss of skeletal muscle mass, quality, and strength.

The good news is that people over 30, 40, 60 and even 70 years old can recover some muscle, strength, but above all, return the functionality of the body, thanks to strength training or weight-bearing 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.

Protein Absorption and Synthesis (Utilization)

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

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

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

This is, according to Phillips, because

“As you get a little bit older, people’s appetites decrease . People tend to gravitate toward different ways of eating, and protein actually becomes a much smaller percentage of the diet. So, by the time I think you need more protein and you want to support muscle mass and lean mass as you get older, most people’s protein intake is actually decreasing to levels where it becomes limiting to how much muscle they can build. ”

As we age, muscle maintenance and mobility are partly promoted by protein intake. 

Nowadays, certain social groups specifically need to pay attention to adequate consumption:

• Overweight and sedentary people who may benefit from calorie 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 elderly people who must prevent and/or combat sarcopenia need even more protein (1.6 g per kg of weight).

Digestion speed affects protein utilization

Just as important as getting an adequate amount of protein is that it is 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 have to space out your protein intake over at least two meals unless you are following the one-meal-a-day protocol.

Several studies have been published using different types of protein such as whey, soy, pea isolates, egg, casein and meat, 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 over a minimum of four meals to achieve 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 do I divide my protein intake throughout the day or, better yet, what is the ideal time to consume protein?

Phillips says the only people who really need to be careful about timing their protein intake are athletes aiming for a competition or Olympic medal; the rest of us mortals can break the fast with protein, meaning our first meal is when we're consuming the highest quality protein.

At the same time, another study on protein consumption indicates that the human body is not designed to absorb more than 20-25 grams of protein per meal, unless it comes from finishing a hard workout or a lot of activity; the rest can go to other parts of the body or be converted into 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 regard, it is not worth consuming excessive amounts of protein or protein shakes, unless you have just finished a hard workout or a lot of activity, but try to adhere to the parameters mentioned, depending on your lifestyle.

Fast-absorbing proteins and other options

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

Whey protein : fast absorption

Isolated pea protein : intermediate absorption

Hard-boiled eggs : intermediate absorption

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

Bone or rib broth : intermediate absorption, but being like shredded meat, it is closer to being a fast-absorbing protein. The same occurs with other animal proteins.

Amino acid complex : generally fast-absorbing, although it depends on the brand and whether it is slow-release.

Casein (dairy): slow absorption

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

Conclusion

A fast-absorbing protein immediately at the end of training in order to provide the “bricks” necessary to rebuild tissue and replenish.  However, once this protein is absorbed, the body is left without protein sources to continue anabolism and is exposed to not being able to rebuild muscle.

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

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 pass or between meals after training, or even during training, where you are not consuming any food.

Products made from casein, such as dairy products, which are slowly absorbed, are best consumed during subsequent meals or during the last meal of the day.

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