Guide to Protein Powder

All you need to know about protein powder and what to buy.

Whether you’re an athlete or looking to lose some weight, protein powder can be a useful tool. However achieving your aims requires a little knowledge about how protein works, which products are suitable and how to use them.

We have brought that information together to help you decide on the products best for you and your goals.


It’s actually less about the protein and more about the amino acids, but its protein which contains these amino acids we need to live. Proteins are made up of chains of amino acids which are linked together by peptide bonds. During digestion the hydrochloric acid in your stomach breaks protein down into smaller peptide chains and amino acids which are absorbed by your body for use.

While your body can make most of the amino acids it needs, there are 9 considered essential which the body cannot create and we must consume.


Once you have consumed protein and absorbed the amino acids, they are put to work throughout your body. Amino acids are used in every part of the body to make all kinds of tissues, enzymes and hormones. This includes your organs, bone, skin, hair and of course muscle. Of course we are most interested in that muscle development and repair!


Ok, we are all unique so this is an inexact science. However there has been a lot of research and there are some good rules to follow when it comes to recommended protein intake.

Consider first that not all protein sources have all of the essential amino acids. If you use protein sources like dairy, eggs or beef you dont need to worry too much as they all contain good levels of amino acids.

If your vegan however, things get a little more complicated. While plant based protein can be very high in certain essential amino acids, few plant based sources have a good level of all the essential amino acids. In fact the only vegan source with a good level of all amino acids is soy. If you are vegan its best to make sure you get your protein from multiple plant based sources. We recommend a blend of rice and pea protein powder.

The next thing you need to consider is your proteins bioavailability to the body. The amount of protein that the body can digest varies depending on the source. There is already a great deal of research on this and we have provided the bioavailability index for various products in a table for you. These indicate the approximate percentage of protein from a source that can be digested by the body. When the score is lower, you need to consume more of the protein over a longer period in order to get the same benefit as a product like whey which has a bioavailability index of 100.

Bioavailability Index
Whey Isolate
  • 100 - 159100%
Whey Concentrate
  • 104100%
Whole Egg
  • 100100%
  • 9191%
Egg White
  • 8888%
  • 8374%
  • 8080%
  • 7777%
  • 6565%
  • 5959%

The next factor to consider is body size. The easiest way to calculate protein intake is as a portion of a persons body weight. This is inexact as Recommended Daily Intake (RDI) does not take into account physical activity above the average. So use the following calculation as a guide only for the average person with average physical activity. We have provided a suggested lower and upper recommendation based on athletic activity. However we recommend you confirm an intake level with your health care professional.

Weight RDI Athlete (low) Athlete (high)
90lbs 41kg 33 56 82
95lbs 43kg 34 59 86
100lbs 45kg 36 62 91
105lbs 48kg 38 65 95
110lbs 50kg 40 68 100
115lbs 52kg 42 71 104
120lbs 54kg 44 74 109
125lbs 57kg 45 77 113
130lbs 59kg 47 80 118
135lbs 61kg 49 83 122
140lbs 64kg 51 86 127
145lbs 66kg 53 89 132
150lbs 68kg 54 93 136
155lbs 70kg 56 96 141
160lbs 73kg 58 99 145
165lbs 75kg 60 102 150
170lbs 77kg 62 105 154
175lbs 79kg 64 108 159
180lbs 82kg 65 111 163
185lbs 84kg 67 114 168
190lbs 86kg 69 117 172
195lbs 88kg 71 120 177
200lbs 91kg 73 123 181
205lbs 93kg 74 126 186
210lbs 95kg 76 130 191
215lbs 98kg 78 133 195
220lbs 100kg 80 136 200
225lbs 102kg 82 139 204
230lbs 104kg 83 142 209
235lbs 107kg 85 145 213
240lbs 109kg 87 148 218
245lbs 111kg 89 151 222
250lbs 113kg 91 154 227


The following 9 essential amino acids are critical for muscle development, muscle energy synthesis, the circulatory and nervous system. These amino acids are essential for healthy muscle development, maintenance, performance and endurance.


Leucine stimulates muscle growth and moderates insulin in the body.


Isoleucine helps produce haemoglobin which carries iron in the blood.


Lysine is used for mineral absorption, muscle repair and growth in the body.


Methionine is used for muscle growth and the production of creatine.


Phenylalanine is used to make epinephrine, norepinephrine and l-dopa.


Threonine is used to create collagen, elastin and muscle.


This amino acid is used to make the neurotransmitter serotonin.


Valine helps in the supply glucose to muscles for use as energy.


Histidine helps in the production of healthy blood cells and histamine.


Your small intestine only has so many transporter cells and this limits the volume of amino acids your body can absorb each hour. Protein absorption varies dependant on the source and type of protein.

Maximum protein absorption rates

While there is much research on the topic, the results on absorption rates are somewhat inexact due to the difficulty in testing this process. The following table should be used as a rough guide.

Note: The digestive process takes approximately 2 to 3 hours. So as a rule of thumb, your body will not use more that 3 times the absorption rate over a 3 hour period. So when taking a whey isolate supplement, you would not require more than 30grams per 3 hour period.

ABSORPTION (Grams Per Hour)


The recommended daily allowance of protein is an inexact science, as your own personal goals and athletic activities contribute to your protein requirements. Figures provided in this section are based on maintenance of current muscle mass. Where additional exercise and muscle building is occurring there is a higher requirement for protein intake.

As a general rule of thumb the following table outlines the calculations for the average person. However these figured do not take into account increased physical activity that an athlete or body builder requires. Therefor the following table should be used as a guide to the absolute minimum daily allowance.

Protein requirements are higher for those performing more rigorous exercise or athletic training. Athletes require higher levels of protein due to increased muscle damage repair as well as support for greater muscle growth, muscle endurance and energy synthesis for muscle cells.

Protein per pound Protein per kg
4 – 13 years 0.43g 0.95g
14 – 18 years 0.39g 0.83g
19+ years 0.36g 0.80g