During January, I like most people, found myself sweating my slightly larger than normal behind at the gym in order to lose the holiday weight and get my New Year’s resolutions on the right foot. Apart from dodging the hundreds of people that flock the gym in Janurary, I also found myself being nearly elbowed in the face by all the people shaking their bottles like in was a Shake Weight dumbbell. As I looked around almost all body types, genders and fitness levels were sculling their powdered protein and water solutions. It seemed to be that people had replaced their chocolate desserts with chocolate protein shakes, as if it would dramatically change them into the next Arnie or Emily Skye. As Carrie Bradshaw would say if she shopped at GNC rather than Gucci, ‘I couldn’t help but wonder, do all these people really need to drink protein shakes?’
Protein is used for the growth and repair of cells in the body including muscle cells. Protein is made up of a range of 20 long chain amino acids. Of these amino acids, 8-9 of them are called essential amino acids, meaning that the human body does not make them and need to be eaten. When choosing protein powders, most dieticians advise the importance of choosing ones with all essential amino acids, in particular leucine. Leucine has been shown to “play a critical role in stimulating muscle protein synthesis” which could assist those whom are trying to rebuild muscle cells after exercise.
Just consuming excess protein will not make your muscles grow. The DAA advises that the best way to build muscle is to engage in muscle strengthening exercises and that although protein can be used as an energy source, carbohydrates are the preferred energy source for exercise. Most Australians get their recommended protein intake from their diet. Sports Dietitians Australia also explain that athletes with higher protein needs tend to increase their protein intake from their appetite and hence supplementation may not always be necessary for athletes. Foods high in protein including lean meats, eggs and legumes. Healthy women aged 19-70 are recommended 46 g/day (0.75 g/kg) of protein and 64 g/day (0.84 g/kg) for healthy men the same age. Protein needs are individual to each person based on gender, exercise level, occupation and health status.
Protein shakes are often consumed for two reasons, weight gain or muscle gain and weight loss or fat loss. The popularity of protein shakes may be down to their convenience, (sometimes) deliciousness or just clever marketing. Health professionals often advise that for adequate synthesis, protein should be consumed no later than 30 minutes after a workout. Therefore protein shakes can be an effective way to get that protein hit in that short window.
Whether you decide that these liquid beverages are for you or not, it is important to understand the differences between the types of protein and what exactly each one does.
Whey protein is probably one of the most popular protein powders available on the market. It is a by-product of cheese making, which results in 20% whey and 80% casein (discussed below). It is popular because it is a high quality protein and is easily digested. It has been used in both weight loss and weight gain products for its high satiety and high levels of protein synthesis amino acid leucine. Whey products can also be useful for lactose sensitive individuals. Whey protein also comes in a variety of forms
- Whey Protein Concentrate (WPC): tends to be the cheapest option of whey powders. Contains small amounts of lactose and typically contains 70-80% protein by weight.
- Whey Protein Isolate (WPI): Further filtration of WPC produces WPI. It contains roughly 90% protein by weight, with limiting lactose and also with very small amounts of fat.
- Whey Protein Hydrolysate (WPH): Tends to be slightly bitter and more expensive than other protein powders. Supposedly has rapid digestion and absorption due to shorter amino acid chains. However evidence on this is conflicting.
Casein makes up 80% of the protein in dairy milk. Casein clots in the acidic stomach therefore it is slower to digest. This means that although there is a slower digestion of amino acids into the muscles, it does mean that absorption may be higher due to greater exposure in the gastrointestinal tract. Casein hydrolysates are available for faster digestion. Also be sure that you are not allergic to the casein protein.
Soy protein is a vegetable protein that has all 8 essential amino acids. Most of the fat, fibre and carbohydrates are removed from powders. Soy protein could be beneficially for heart health as some isoflavones can have antioxidant effects and is also cholesterol free. Soy protein like whey protein, is rapidly digestible however tends to be much cheaper than whey.
The Cancer Council does not support the use of soy protein supplements as large amounts of soy potentially could have negative impacts on women with existing or previous breast cancer. In contrast however phytoestrogens have been shown to reduce menopausal symptoms in some women.
Too much of a good thing?
You may not have thought about it but consuming too much protein can be a bad thing. Unlike glycogen, amino acids are not stored in the body for later use. Instead the body aims to keep itself in nitrogen balance and excretes excess nitrogen via urine, sweat and faeces. Therefore consuming more protein than you require can actually be redundant (and expensive). However when there is a significant excess of protein, an excessive amount of ketone bodies can be made. As your kidneys try to ‘flush out’ the toxic ketones, excessive water is lost, which could lead to dehydration and dizziness.
There are many advantages and disadvantages to protein shakes. Before changing your diet or exercise regime it is important that you speak to your local GP, dietitan or pharmacist to evaluate your individual protein and nutrition needs.
- Sports Dietitians Australia. Protein and Amino Acid Supplementation for Athletes – Fact Sheet. http://www.sportsdietitians.com.au/content/2562/ProteinandAminoSupplementationforAthletes/ (accessed 22 January 2015).
- Whitney E, Rolfes SR, Crowe T, Cameron-Smith D, Walsh A.Understanding Nutrition: Australian and New Zealand Edition. South Melbourne, Australia: Cengage Learning Australia Pty Limited; 2011.
- Brown A. Understanding Food: Principles and Preparation, 4th ed. Belmont, CA: Wadsworth Cengage Learning; 2011.
- Caspero A. Protein and the Athlete – How Much Do You Need? http://www.eatright.org/resource/fitness/sports-and-performance/fueling-your-workout/protein-and-the-athlete (accessed 24 January 2015).
- Dietitian Association of Australia. Protein. http://daa.asn.au/for-the-public/smart-eating-for-you/nutrition-a-z/protein/ (accessed 24 January 2015).
- National Health and Research Council. Protein. https://www.nrv.gov.au/nutrients/protein (accessed 23 January 2015).