Updated: Dec 16, 2020
I have studied nutrition science for several years now. In that time, I have come across many, many different theories and alternative medicine practices that have been used to assess and diagnose supposed nutritional deficiencies in people. So many of these are not based on sound science and, in some cases, defy the laws of chemistry, biochemistry, and physics. Such is the case in Nutrition Response Testing (NRT). Another name for this is Applied Kinesiology (AK). Many naturopaths and chiropractors use it to assess nutritional shortcomings and then sell supplements based on those deficiencies and “cure” many of their ailments. Let’s get started explaining what NRT is and why it isn’t a valid method for treating nutritional deficiencies and physiological problems.
First, there are two phases of NRT: the analysis and the personalized health improvement program. The investigation is performed simply by using your body’s muscle groups in combination with acupressure points to determine where the underlying weakness is in the body. Using the same technique, they supposedly design a natural health improvement program to help you handle what they find in the analysis.
STEP ONE: THE ANALYSIS
The analysis is done by testing the body's neurological reflexes and acupressure points. The acupuncture points are selected from the ancient Chinese acupuncture system, which is thousands of years old. Holistic health practitioners claim NRT is a study of how the different points on the body's surface relate to health and the flow of energy in every organ and function. This is false and cannot be proven biochemically. It sounds great, but you find them to be grossly misrepresented when you strip these theories down to the molecular level.
In Nutrition Response Testing, instead of connecting electrodes to the specific points being tested, the practitioner contacts these points with his/her hand. On the other hand, he/she will test the muscles of your extended arm. If the reflex being contacted is active, the nervous system will respond by reducing energy to the extended arm, and the arm will weaken and drop. This drop signifies underlying stress or dysfunction, which may be affecting your health. Again, there is nothing valid or scientific about this process. You do not measure a nutritional deficiency by testing this way. You CAN assess nutrient shortcomings by physical manifestations such as discolored skin, dry eyes or mouth, jaundice, acne, etc.
STEP TWO: PRESCRIBING SUPPLEMENTS
The next step is to test specific high-quality nutritional supplements against those weak areas to find which ones bring the reflexes back to strength. The supplements are costly and are personalized to correct the deficiency and restore the correct reflexive balance.
There is a limit to what supplements can do for you. Your body utilizes nutrients from real food much differently than in a concentrated form of a supplement. When you eat food, there are many other components, such as other vitamins, minerals, fiber, protein, carbohydrates, fat, etc. This matters in how they are biochemically processed. Expensive supplements are not a miracle cure, and in some cases, can do more harm than good.
Supposedly an NRT analysis is done on each client over numerous visits, revealing layers of dysfunction these can be addressed. Note: Without a biochemical examination, you could not assess nutrient deficiencies with this much accuracy.
WHY NRT OR APPLIED KINESIOLOGY IS WRONG
According to the Journal of the American Dietetic Association, 1988 Jun;88(6):698-704:
"Applied kinesiology is a technique used to assess the nutritional status on the basis of the response of muscles to mechanical stress. In this study, 11 subjects were evaluated independently by three experienced applied kinesiologists for four nutrients (thiamin, zinc, vitamin A, and ascorbic acid). The results obtained by those applied kinesiologists were compared with (a) one another, (b) standard laboratory tests for nutrient status, and (c) computerized isometric muscle testing. Statistical analysis yielded no significant interjudge reliability, no significant correlation between the testers and standard biochemical tests for nutrient status, and no significant correlation between mechanical and manual determinations of relative muscle strength. The subjects were exposed in a double-blind fashion to supplements of thiamin, zinc, vitamin A, ascorbic acid, and two placebos (pectin and sucrose) and then re-tested. According to applied kinesiology theory, “weak” (indicating deficiency) muscles are strengthened when the subject is exposed to an appropriate nutritional supplement. Statistical analysis revealed no significant differences in response to placebo, nutrients previously determined (by muscle testing) to be deficient, and nutrients previously determined (by muscle testing) to be adequate. Even though the number of subjects (11) and nutrients (4) tested was limited, THE RESULTS OF THIS STUDY INDICATED THAT THE USE OF APPLIED KINESIOLOGY(NRT) TO EVALUATE NUTRIENT STATUS IS NO MORE USEFUL THAN RANDOM GUESSING."
WHAT ABOUT THE REFLEXIVE RESPONSE THAT APPEARS TO BE HAPPENING?
According to Steven Novella, a clinical neurologist at sciencebasedmedicine.org, “… it is possible to distinguish genuine weakness from decreased effort. This is a distinction that clinical neurologists have to make all the time. If a muscle is genuinely weak, it will behave differently from a muscle that is not weak but where the person is giving less than full effort – for whatever reason, and regardless of whether or not they realize they are giving less than full effort. We will then describe such weakness as “effort-dependent” or “effort-limited.” One key feature of effort-limited weakness is that it tends to give way. The strength is greater at first but then will suddenly decrease or give way….
In other words – the weakness is not real; it is due to a decreased effort on the part of the subject due to (apparently) his belief that his muscles should be weak under the proper circumstances. In other words, – self-deception,”
THE BOTTOM LINE
Nutrition Response Testing has no basis in scientific fact. There have been several research studies done to prove this. Here are three:
The best way to correct nutrient deficiencies is to eat a diet rich in fruits and vegetables, lean meats, beans, lentils, limited low-fat dairy, whole grain, and other complex carbohydrates. If you need further direction on how to go about doing this, consult a Registered Dietitian who is most qualified to dispense advice on nutritional deficiencies, food allergies, and intolerances.,