Protein, protein powders and muscle building. Are protein supplements suitable for teenagers ?
Almost every list of New Years Resolutions has “getting into shape” at number one, a resolution to be fitter, more toned or have a different body. Historically this would have meant being smaller or thinner but now it is just as likely, particularly in boys, to mean a desire to bulk up, build muscle, get a six pack or be ripped.
Like googling ‘weight loss’, googling ‘muscle gain’ results in literally thousands of articles, YouTube clips and forums, offering a vast array of guaranteed methods to increase muscle and change your shape. Although often written with the best intentions, many programs are totally unsuitable for young people and completely without scientific basis. Almost all recommend the use of a protein supplement, powder or shake.
The total number of muscle fibres in the body is fixed at or soon after birth and muscle growth during your life predominantly works by lengthening and thickening these fibres. Between the age of one and the end of adolescence, muscle fibre diameter will naturally increase and results in a corresponding increase in total muscle mass and strength. The timing of this increase and how the muscle is distributed will vary between individuals and is determined by genetics as well as environment or training. In boys muscle as a proportion of body mass rises from ~42% at age 5, to ~53% at age 17. This change is not seen in girls whose muscle proportion stays at around 41%.
Muscle fibres are predominantly made from protein.
In adults approximately 16% of total body weight is protein. 43% of this is in muscle, 15% skin and 16% blood. Enzymes, hormones, neurotransmitters and many other key elements of the body are also protein based. All protein in the body is in a constant state of flux – all protein structures are constantly being broken down and rebuilt.
The recommended daily intakes of protein in the UK vary with age and are shown in the table below. These numbers are approximations built on a recommended intake of 0.75g/Kg bodyweight/day in adults and slightly more in adolescents and children. Research has shown children aged 7-10 years should consume 1.1-1.2 g/kg per day, and children aged 11-14yrs 1.0 g/kg per day to allow for all repair, growth and development. These numbers will be slightly higher in children who are in regular training but there is such a thing as too much protein, with high intakes having some quite serious side effects. There hasn’t been equivalent research in children but adult studies have shown that the maximum safe intake is between 2 and 2.5 g/kg of body weight per day. Intakes greater than this level may stress kidney and liver function, cause leaching of calcium from bones, kidney stones and fatigue. Use of whey products have also been associated with increased acne.
If energy intake is insufficient protein structures will be broken down to produce energy BUT if protein intake is higher than needed it is not stored as protein structures (eg Muscle) it is converted to and stored as fat.
|AGE IN YEARS||PROTEIN REQUIREMENT|
|11-14||MALE 42.1g FEMALE 41.2g|
|15-18||MALE 55.2g FEMALE 45.0g|
|19-50||MALE 55.5g FEMALE 45.0g|
|51 and over||MALE 53.3g FEMALE 46.5g|
PROTEIN IN THE DIET
A good list of common foods and their protein content can be found on the British Nutrition Foundation website or individual foods can be found at SELF Nutrition Data. A wide variety of nuts, seed, fruit and vegetables contain protein as well as the better recognised sources of meat, fish and dairy products. Protein intakes in the UK are good and even an active 16yr old boy’s requirement of 55-58g protein/day can be easily obtained in a standard diet without the need for supplementation.
Breakfast consisting of a slice of toast with peanut butter (~9g protein) and a glass of milk (~8g), a lunch of baked potato (~4g) with beans (~14g), salad and cheese (~5g) and a supper including a chicken breast (~35g), would give you a whopping total of 75g. Distributing total protein intake like this over all meals / snacks has been shown to be much better for muscle protein synthesis (25% higher) than if the protein is consumed just at an evening meal.
To successfully build muscle you need three things
- to work the muscle and
- to eat an adequate diet containing enough energy and the right nutrients.
Muscle is not fixed, all muscle is constantly being broken down and rebuilt.
- The right sort of exercise will ensure that as it is rebuilt, it will be built bigger and stronger.
- The right diet will ensure that there the right building blocks for growth are available.
- The wrong diet, with inadequate energy content will result in muscle being broken down (for energy) despite the right exercise being done.
Maintaining an active lifestyle is important for maintaining muscular fitness but to specifically build muscle, a specially designed resistance training program is needed. For this I would recommend talking to a qualified strength and conditioning coach. A progressive resistance training program can produce gains of 25-100% in as little as 3month but much of the early improvements in strength may be down to improved technique and an individual learning how to effectively produce force, rather than noticeable increases in muscle size.
Lasting gains in muscle mass may take 6months or longer and there is no scientific evidence that this can process can be sped up by using diet or supplements. A sample workout designed for college students can be found on Stack.com here.
MUSCLE BUILDING SUPPLEMENTS.
As I have shown above, using protein supplements is not strictly speaking necessary but if for some reason you feel that they may be needed, here are some things that you may want to know. I would recommend that you do not buy off the internet, there is no guarantee that you will be getting the best product for you or even the product you think you are getting. The best place to go is a specialist shop like GNC, where all the staff have specific training and are able to give you advice. Buying from a supermarket is fine when you are familiar with the products but many of the supplements contain added ingredients that are not suitable for children and it is not always clear.
All though there is no scientific evidence of any benefit, protein shakes are probably the most widely used supplement by teenagers. The shakes tend to consist of whey protein, although casein (also from milk), soy, egg, hemp, rice, and pea protein powders are also available.
Milk and egg protein is possibly the best starting place if you are looking at using supplements. Milk contains both whey and casein proteins and egg protein is of very high quality, easily digested and has a good mix of amino acids. I have written about milk (Milk the new sports drink & Cows Milk : healthy or bad for you) and eggs (Eggs for performance : Go to school on an egg) and their health benefits in previous posts and these are worth reading. Milk and Egg protein powders vary and its worth looking for ones with no added supplements. The benefit of having both whey and casein protein as well as egg protein is that they all have slightly different digestive profiles, giving you both quick release and slower digested protein. As I have said above all protein structures are constantly being broken down and rebuilt. Research has shown that whey protein is quickly digested and particularly good at promoting assimilation of muscle but has no effect on muscle breakdown. Casein is slower to digest and has a lower effect on muscle assimilation but also acts to slow muscle breakdown. This fact along with the many other benefitial nutrients in milk mean that many nutritionists favour the whole food rather than the processed factions of either whey or casein.
Whey protein was originally used as it is a handy by-product of cheese and Greek yoghurt making (so relatively cheap). Whey contains all of the nine essential amino acids that facilitate the healing and rebuilding of damaged muscles and is known for its fast digestion and assimilation. First generation whey protein powders (also known as concentrates ) had protein levels of only 30-40% and contained high amounts of the milk sugar lactose and fat. Modern whey powder concentrates however contain protein levels as high as 70-80% and reduced amounts of lactose and fat. They are generally slightly less processed than other forms of whey powder and may also contain good natural minerals and vitamins as well as other bioactive compounds from milk, such as growth factors, phospholipids, immunoglobulins, lactoferrin and conjugated linoleum acid, which although not associated with muscle building may have other health benefits.
Another sort of whey protein powder is a whey protein isolate. Isolates contain as much as 90-96% protein, the whey concentrate having been further processed to remove lactose sugar and fats. To do this the protein must be very carefully processed under low temperature and/or low acid conditions so as to not “denature” the protein. The advantage of a good whey protein isolate is that it contains more protein on a gram for gram basis but because of the complicated manufacturing process care must be taken when considering a cheap isolate brand. The most sort after type of isolate is known as ‘ion exchange isolate’ but there is no scientific evidence that it is superior. In the past isolates were thought to taste bad, modern isolates are better but be careful that this is not because there is lots of added sweeteners.
Whey protein hydrolysate or hydrolysed whey proteins contains protein that has been further processed and partially ‘broken down’ so they are absorbed faster. Whether this is a benefit for athletes is yet to be proven but it has been sown to be beneficial in burn victims, people with certain digestive disorders and pre-term infants. Early versions of hydrolysed protein tasted terrible and were very expensive but new brands have been coming out and despite little scientific backing have become popular with body builders..
Casein Protein is not as commonly used by body builders but is a good slow release protein source and is often used after exercise or in the evening before bed.
As well as individual protein powders, there are a number of blends on the market. These may include a range of proteins but are also often mixed with carbohydrates. A range of proteins are mixed with oats and marketed as breakfast supplements, or high levels of carbohydrates and marketed either as recovery drinks (ideally 4:1 carb:protein) or bulking drinks. A blended protein drink maybe of some benefit if it is correctly tailored to your needs and not too heavily processed.
OTHER SUPPLEMENTS OFTEN INCLUDED IN POWDERS.
Creatine has been popular with athletes, weightlifting and body builders for a while. It is meant to work by increasing the supply of ATP (the main energy source for muscles) to muscles during exercise, allowing for harder training and consequently stimulating greater muscle growth. Lots of people swear by it and there is good evidence that supplementation both increases phosphocreatine stores and allows greater training intensity and better recovery. Early research and popular press contained concerns about the use of creatine supplementation and kidney function in high doses or increased risk of muscle injury during exercise but trials have now ruled out many of the early concerns. It is still recommended that anyone with a pre-existing kidney function abnormality consults a doctor before use and supplementation can cause water retention and weight gain. Creatine has not been tested in children and I feel its use is unnecessary for adolescent athletes although it is common. A varied omnivore diet contains around 4g of creatine and elite or well trained adult athletes are found to benefit very little from supplementation.
Glutamine is the most abundant free amino acid in the body and as amino acids are the building blocks of protein / muscles it does have a role in muscle growth. Glutamine is produced in the muscles and is distributed by the blood to the organs that need it. Glutamine has also been associated with good gut function, the immune system, and in providing “fuel” (nitrogen and carbon) to many different cells in the body.
If the body uses more glutamine than the muscles can make (i.e., during times of stress), muscle wasting can occur and this has lead to the assumption that glutamine may prevent muscle breakdown in times of activity or stress.
Although thought to be safe with few side effects, there is no evidence that glutamine is benefiticial for building muscle and no research has been done in adolescents.
Branched-chain amino acids are essential nutrients that the body obtains from proteins found in food, especially meat, dairy products, and legumes. They include leucine, isoleucine, and valine. “Branched-chain” refers to the chemical structure of these amino acids. Leucine is known to be specifically important in muscle building acting as a switch to turn on muscle hypotrophy. Branched-chain amino acids are used to help slow muscle wasting in people who are confined to bed with some success but to build new muscle all the amino acids have to be there. Supplementing with any one amino acid can affect the absorption and availability of others and trails have not found any benefit when supplementing leucine or BCAAs alone.
Some people also use branched-chain amino acids to prevent fatigue and improve concentration. Branch chain amino acids have been tested in children and are thought to be safe but side effects including extreme fatigue and poor coordination are common.
Most diets in the UK are high in protein and it is unlikely that eating extra protein will have an impact on muscle growth or training adaptation. If you are concerned that your diet may be too low, or your intake is uneven over the day it is worth making sure you have at least one high protein food at each meal. It is also possible to eat high protein snacks such as nuts or cheese.
Although I think almost all supplements are unnecessary the temptation for teenagers to seek performance in a bottle is understandable. If you decide to use a supplement its worth asking
- Is it necessary ?
- Is it safe?
- Are there potential side effects ?
- Is it cost effective
- Might it contain a banned substance ?
Many protein supplements and recovery drinks are also laced with added minerals and vitamins. Although these may be beneficial, it’s worth remembering that too much of anything may be harmful and that research has tended to find that real food is better.