Determining your metabolic type: what can and cannot be measured
The most important points at a glance
There is no metabolic type as a fixed category in any vetted source. We searched the consumer advice center, the DGE, the BfR, IQWiG, and the MSD Manual: neither carbohydrate type nor protein type nor a faster or slower metabolism appears there as a recognized concept. The North Rhine-Westphalia Consumer Advice Center states that personalized dietary recommendations from commercial providers are not evidence-based (2023).
Instead, other things can be measured, and measured precisely. The DGE provides a formula for resting energy expenditure, along with PAL factors between 1.2 and 2.4 for calculating total energy expenditure. Reference ranges with numerical values exist for blood values such as HbA1c, fasting glucose, cholesterol, and TSH. This is the level at which something can be determined.
You will first read where the typology comes from and what the evidence says about it. This is followed by the established metrics: basal metabolic rate, resting energy expenditure, the PAL factor, and blood values with their reference ranges. Finally, we explain what a genetic test can and cannot do in this context.
What to expect in this article
1. Where the typology comes from
2. What the evidence says about it
3. Basal metabolic rate: the precise definition
4. Three statements about metabolism put to the fact check
5. The formula used for the calculation
6. The PAL factor in numbers
7. Where energy goes in the body
8. Which blood values reflect metabolism
9. Four ways to determine metabolism
10. What a genetic test can do in this context
11. Limitations: what this article does not answer
12. What remains of metabolic analysis
Frequently asked questions
Sources
Where the typology comes from
The idea that people can be divided into metabolic types is intuitively appealing. It promises that there is a reason why the same diet affects two people differently, and that this reason can be named.
The underlying observation is correct. People respond differently, and the energy requirements of two people with the same weight may differ. The leap from this observation to fixed categories is the point at which the evidence ends.
Key message
Differences between people are well documented. Fixed types into which these differences can be sorted are not.
Why categories are so appealing
A category saves the work of observation. Those who know their type no longer have to try things out, but only look them up. That is the true selling point of typology.
The price of that is accuracy. An assignment that is not supported by evidence influences every decision without being verifiable. Those who eat according to their type and do not succeed look for the error in themselves rather than in the classification.
What the term means in everyday life
In conversations, metabolic type usually refers to one of three experiences. The first is that someone gains weight easily despite eating little. The second is that someone tolerates certain foods less well than others. The third is that the same diet affects two people differently.
There are explanations for all three experiences that do not rely on typology. The first concerns the activity factor and the accuracy of one’s own estimate, the second concerns intolerances assessed through one’s own diagnostic process, and the third concerns adherence and baseline values.
The rest of this article works through these explanations. They are less catchy than assigning a type and have the advantage that each comes with a number.
What the evidence says about this
In 2023, the Consumer Advice Center NRW published a reprint on personalized nutrition and compiled the assessments of several professional organizations. One sentence from it summarizes the situation.
Documented source
“Personalized dietary recommendations, as currently offered primarily by commercial companies, are not evidence-based.”
Consumer Advice Center NRW
Personalized Nutrition, reprint from Knack•Punkt, as of 2023
We quote this sentence even though mybody®x itself offers DNA tests for nutrition. Omitting it would have been the more convenient choice. What this means for our own offering is addressed in Chapter 10, and it does lead to a consequence.
What the professional organizations specifically criticize
The same reprint quotes a DGE working group stating that it is currently not possible to provide personalized, evidence-based dietary recommendations based on genetic makeup or the composition of the gut microbiota.
The methodological core appears in another sentence: There is insufficient evidence from randomized controlled trials on the effectiveness of incorporating genetic tests into nutritional counseling. The criticism is therefore not that genetic differences exist, but that their usefulness for dietary recommendations has not been demonstrated.
A figure from the same document shows why. There are 941 known genetic loci for obesity, and 240 genetic loci have been identified for type 2 diabetes. Deriving a recommendation for action from hundreds of individual contributions is different from reading a single marker.
Basal metabolic rate: the precise definition
When the typology is set aside, the question of energy requirements remains. It can be answered, and the answer begins with a definition that is more precise than the everyday use of the word.
The Verbraucherzentrale describes basal metabolic rate as the energy required to maintain normal bodily functions. The DGE adds the measurement conditions: basal metabolic rate is the result of a measurement conducted under precisely standardized conditions—namely, in the morning after approximately eight hours of sleep, in a thermoneutral environment, and around twelve hours after the last meal.
Why something else is measured in practice
These conditions cannot be recreated in everyday life. Therefore, measurements use resting energy expenditure, which is determined under less strict conditions. The DGE states the difference: resting energy expenditure is approximately 10 percent higher than basal metabolic rate.
Ten percent may sound like little, but it is not. With 1,600 kilocalories, the difference is 160 kilocalories. Anyone comparing two values from two sources without checking which of the two quantities is meant is comparing two different things.
The same source mentions a third value that is often omitted. The thermic effect of food, meaning the energy required for digestion and processing, accounts for about 10 percent of total energy expenditure.
Three terms that cannot be used interchangeably
This leaves three values side by side, and each calculator site on the internet refers to a different one. Basal metabolic rate is the value under the strictest measurement conditions. Resting energy expenditure is around 10 percent higher. Total energy requirements result from multiplication by the activity factor.
When two calculators produce different results, they are usually not based on contradictory formulas but on different target values. This mix-up explains much of the confusion surrounding the subject.
For everyday purposes, this means checking first which of the three values a calculator provides. Without that information, the number cannot be interpreted and is useless for comparison.
Three statements about metabolism in a fact check
Three statements appear in almost every text on the subject. We test them against the sources we read for this article.
Claim and evidence
“I have a slow metabolism”
No reviewed source describes this as a fixed characteristic. What does exist is a calculable resting energy expenditure that depends on weight, age, and sex, as well as a PAL factor for activity. Both values explain differences between people without requiring a type for that purpose.
“My genetic test tells me how I should eat”
The North Rhine-Westphalia consumer advice center states that there is insufficient evidence from randomized controlled trials on the effectiveness of incorporating genetic testing into nutritional counseling (2023). A genetic test describes predispositions; it does not prescribe a meal plan.
“The right method can boost your metabolism”
The opposite direction is supported by evidence. According to the consumer advice center, basal metabolic rate decreases after crash diets because the body conserves energy. For this article, we did not find an institutional source supporting a method for increasing basal metabolic rate.
The three points have one thing in common. They treat metabolism as a characteristic you have, rather than as a calculation that can be performed. That exact distinction determines whether a number is produced.
The formula used for the calculation
The DGE publishes formulas that can be used to estimate resting energy expenditure. They require two figures: body weight in kilograms and age in years.
For women, it is: weight times 0.047, minus age times 0.01452, plus 3.21, with the result multiplied by 239. For men: weight times 0.047, plus 1.009, minus age times 0.01452, plus 3.21, with the result multiplied by 239. Both yield kilocalories per day.
A calculation example
For a 70-kilogram, 40-year-old woman, the formula gives: 70 times 0.047 equals 3.29. Minus 40 times 0.01452, or 0.58, leaves 2.71. Plus 3.21 equals 5.92. Times 239 is around 1,415 kilocalories per day.
This value is an estimate, not a measurement. Anyone who wants a more precise figure needs indirect calorimetry, which measures oxygen uptake and carbon dioxide output. This is a procedure for clinics and studies, not for home use.
What is notable about the formula is what it does not include. It contains no body type, gene variant, or category. The only input variables are weight, age, and sex.
The PAL factor in numbers
Multiplication takes you from resting energy expenditure to total requirements. The consumer advice center states the calculation simply: basal metabolic rate multiplied by PAL equals total energy requirements. PAL stands for physical activity level.
PAL factors according to the DGE
1,2–1,3
frail or immobile people
1,4–1,5
office workers, i.e. predominantly sedentary work
1,8–1,9
predominantly standing and walking activities, such as in retail or service
2,0–2,4
physically demanding work or competitive sports
Source: German Nutrition Society (DGE), Frequently Asked Questions About Energy Intake, and Consumer Advice Center NRW, Nutrition, Energy Expenditure, Calories (as of 2026)
What the range means
The factor between 1.2 and 2.4 is two. Applied to our example value of 1,415 kilocalories, this yields a range of around 1,700 to 3,400 kilocalories per day.
This is the true core of the observation from which the somatotype theory arose. Two people with the same weight and age can differ in their daily energy requirements by more than a thousand kilocalories. The reason is physical activity, not body type.
The calculation also shows the share of basal metabolic rate in total energy expenditure. With a PAL of 1.4, it is mathematically around 71 percent; with a PAL of 2.0, around 50 percent. These two percentages are derived from the DGE formula and do not appear verbatim in the source.
Where the body's energy goes
The consumer advice center breaks down which organs account for basal metabolic rate. Two figures are revealing because they contradict a widespread assumption.
The brain accounts for 25 percent of basal metabolic rate, while all muscles combined account for 18 percent.
The widespread assumption is that muscle mass is the decisive factor in basal metabolic rate. According to these figures, the contribution of muscle at rest is lower than that of the brain. Muscles consume a lot when they work and little when they rest.
What this means for everyday life
Strength training remains worthwhile, but the rationale shifts. The additional expenditure occurs mainly during the exertion, not afterward while sitting in an armchair. Anyone who presents muscle gain as a route to a permanently higher basal metabolic rate is exaggerating the scale of the effect.
Conversely, the brain's share explains why basal metabolic rate cannot be controlled voluntarily. One quarter goes to an organ whose energy expenditure is not significantly altered by either training or diet.
The leverage lies elsewhere
The three components of energy expenditure produce a clear hierarchy of how readily they can be influenced. Basal metabolic rate is largely determined by weight, age, and sex. The thermic effect of food is around 10 percent and depends on the amount eaten.
That leaves the activity component, and this is precisely where the range from 1.2 to 2.4 lies. It is the only component that can be changed by a decision, and at the same time the one with the greatest room for movement.
This puts the entire search for a type into perspective. Anyone who wants to know why their requirements differ from those of another person will usually find the answer in the PAL factor, not in a category.
It is important to note that the PAL factor reflects the entire day, not the exercise session. One hour of training raises the value only slightly on an otherwise sedentary day. What shifts the factor is the overall structure of everyday life.
Which blood values reflect metabolism
Where typology provides no number, laboratory values do. Reference ranges with clear thresholds exist for several measurements.
For HbA1c, IQWiG specifies three ranges: below 5.7 percent, equivalent to 39 millimoles per mole of hemoglobin, indicates no diabetes; 5.7 to 6.4 percent is considered an elevated risk; and from 6.5 percent, diabetes mellitus is present. For diagnosis, the same source gives a fasting blood glucose level above 126 milligrams per deciliter and a two-hour value above 200 milligrams per deciliter in the glucose tolerance test.
Blood lipids and thyroid
For LDL cholesterol, IQWiG gives a reference value below 130 milligrams per deciliter for adults over 18, equivalent to below 3.36 millimoles per liter. For HDL cholesterol, it specifies above 50 milligrams per deciliter for women and above 40 for men.
For the TSH level, which reflects thyroid function, the guideline of the German Society for General Practice and Family Medicine specifies age-dependent thresholds: A level above 4.0 milliunits per liter is considered elevated in people aged 18 to 70, above 5.0 in those aged 70 to 80, and above 6.0 in those over 80. The same guideline notes that laboratory reference ranges vary between 2.5 and 5.0.
The final half-sentence is the most important one in the chapter. Reference ranges differ between laboratories and methods. The range shown on your own report is always decisive.
Why these values show something different from energy needs
One misunderstanding is worth clarifying. Neither HbA1c nor TSH nor blood lipids say anything about how many kilocalories a person needs per day. They describe how the body handles what arrives.
The HbA1c value reflects a longer period than a single blood glucose measurement because it is attached to red blood cells and follows their lifespan. This makes it more robust against the effect of a single meal.
The TSH value, in turn, is a control signal, not a thyroid hormone. It shows how strongly the control center is signaling for more. That is precisely why it rises when the thyroid supplies too little, which initially contradicts everyday logic.
As for the question of metabolic type, the conclusion is this: These values also provide no category. They provide numbers with a reference range, and a value outside that range is cause for medical evaluation.
Four ways to determine metabolism
The table places the four common approaches side by side. The last two columns are decisive.
| Approach | What comes out of it | Institutional evidence |
|---|---|---|
| Formula according to the DGE | Resting energy expenditure in kcal per day, estimated from weight, age, and sex | The DGE itself publishes the formula and PAL factors |
| Indirect calorimetry | Measured rather than estimated value under standardized conditions | The DGE explicitly describes the measurement conditions for basal metabolic rate |
| Blood values | HbA1c, fasting glucose, blood lipids, and TSH with reference ranges | Reference ranges are stated numerically by IQWiG and in guidelines |
| Genetic test for nutrition | Description of genetic predispositions, no calorie target | No sufficient evidence from randomized controlled trials to support its inclusion in nutritional counseling |
The fourth line concerns our own offering, and it appears here unchanged. The next chapter clarifies what follows from it.
What a genetic test can do here
A DNA test for nutrition does not determine a metabolic type, because no such type exists. Nor does it provide a calorie target, because the formula in Chapter 5 together with the PAL factor is sufficient for that.
What it describes are genetic predispositions—that is, variants that do not change over the course of life. Whether and to what extent a dietary recommendation can be derived from them remains unclear based on the available evidence. The North Rhine-Westphalia Consumer Advice Centre explicitly takes a cautious view, and this finding also applies to our tests.
mybody®x works with a certified specialist laboratory in Germany, evaluates results in compliance with the GDPR, and has been active since 2016, including in the direct-to-consumer sector since 2022.
DNA test from saliva
DNA metabolic analysis | including a 28-day plan & recipe book
More than 80 genetic variations from a saliva sample, evaluated in 24 analysis reports, plus a 28-day plan with 60 recipes. What the test does not do: It does not determine a metabolic type, because this concept does not exist in any source reviewed. It does not provide a diagnosis or replace medical advice. The North Rhine-Westphalia Consumer Advice Centre considers nutrition recommendations based on genetics to be unsupported by evidence.
Product page information, accessed 11 August 2026
There is also a legal point to note. Genetic examinations for medical purposes in Germany are subject to the German Genetic Diagnostics Act. It requires a physician’s involvement and, before consent is given, information about the nature, significance, and scope of the examination.
Chapter at a glance
A genetic test describes predispositions and does not determine a metabolic type. For energy requirements, the formula and PAL factor are sufficient; for metabolic status, blood values together with their reference range are needed. Medical conclusions are subject to the German Genetic Diagnostics Act, which reserves such matters to physicians.
Limitations: what this article does not answer
Despite a targeted search, we did not find a statement from the German Federal Institute for Risk Assessment specifically on genetic tests for nutrition and weight loss. The BfR does not address this topic in the documents reviewed, so we make no claim about its position.
The two percentages for the share of basal metabolic rate in total energy expenditure, 71 and 50 percent, are derived from the DGE formula and do not appear verbatim in the source. We therefore label them as calculations in both places.
The special publication by the North Rhine-Westphalia Consumer Advice Centre names two commercial test products and their prices. We do not repeat these names because we generally do not name competitors. Nevertheless, the substantive assessment is provided in full in this text.
Finally, a boundary concerning our own role. Abnormal blood values should be medically assessed. This article provides reference ranges so that a finding can be understood, not so that anyone can assess themselves.
What remains of metabolic analysis
If you take one number away from this article, let it be your own PAL factor. It is the only variable you can influence yourself, and also the one with the widest range.
The calculation method is openly available. Resting energy expenditure from the formula, multiplied by the PAL value for your activity level. Between an office day with 1.4 and a physically demanding day with 2.0, the difference for our example value is around 850 kilocalories.
It all began with the question of one’s own metabolic type. The most honest answer is that the question is wrongly framed. What you have is a requirement, and it can be calculated rather than guessed.
Frequently asked questions
Does metabolic type really exist?
None of the sources reviewed for this article identifies metabolic type as a recognized concept. The North Rhine-Westphalia consumer advice center states that personalized dietary recommendations from commercial providers are not evidence-based (2023). Instead, resting energy expenditure, the PAL factor, and blood values with reference ranges can be measured.
How do I calculate my basal metabolic rate?
The DGE publishes a formula for resting energy expenditure. For women: multiply weight in kilograms by 0.047, subtract age in years multiplied by 0.01452, add 3.21, and multiply the result by 239. For men, add 1.009 as well. The result is kilocalories per day. According to the same source, resting energy expenditure is about 10 percent higher than actual basal metabolic rate.
What is the PAL factor?
The PAL factor reflects activity level and is multiplied by basal metabolic rate to determine total energy needs. The DGE gives values of 1.2 to 1.3 for frail or immobile people, 1.4 to 1.5 for office workers, 1.8 to 1.9 for predominantly standing jobs, and 2.0 to 2.4 for heavy physical work or competitive sports.
Which blood values indicate metabolism?
IQWiG classifies HbA1c below 5.7 percent as unremarkable, 5.7 to 6.4 percent as an increased risk, and 6.5 percent or higher as diabetes mellitus; for LDL cholesterol in adults, below 130 milligrams per deciliter. For TSH, the DEGAM guideline classifies values above 4.0 mU/l as elevated in people aged 18 to 70. Reference ranges depend on the laboratory and method.
Do muscles burn a lot of energy at rest?
Less than is often assumed. The consumer advice center puts the share of muscle in basal metabolic rate at 18 percent and that of the brain at 25 percent. Muscles primarily use energy during exertion. Strength training remains beneficial, but it does not increase basal metabolic rate to the extent often promised.
Next step
Two numbers instead of one category
Calculate your resting energy expenditure using the DGE formula and choose the PAL factor that matches your daily work routine. The result is more reliable than any type classification. Anyone who also wants to see the genetic level can find it in the DNA Metabolism Analysis.
DNA Metabolism Analysis Calculate calorie needsRead more
You might also be interested in
The calculation process in detail, if the number interests you more than the concept.
The genetic level in detail, including the cases in which it actually matters.
Sources
- Consumer Advice Center NRW: Personalized nutrition. Special print from Knack•Punkt, issue 1/23, as of 2023 – verbraucherzentrale.nrw
- German Nutrition Society (DGE): Frequently asked questions about energy intake, with formulas for resting energy expenditure and PAL factors – dge.de
- Institute for Quality and Efficiency in Health Care (IQWiG): Overview of laboratory values with reference ranges for HbA1c, blood glucose, and blood lipids – gesundheitsinformation.de
- DEGAM and AWMF: S2k guideline on elevated TSH levels in general practice, registration number 053-046, as of 2024 – register.awmf.org
The verbatim quote concerning the lack of an evidence base, the DGE working group's finding on genetic makeup, the reference to the lack of randomized controlled trials, the 941 and 240 gene loci, and the organ proportions of 25 and 18 percent come from source [1]. The definition of basal metabolic rate, the formulas, the 10 percent difference from resting energy expenditure, the thermic effect of food, and the PAL ranges come from [2]. The reference ranges for HbA1c, fasting glucose, LDL and HDL cholesterol come from [3], while the age-dependent TSH limits come from [4]. The information on the decline in basal metabolic rate after crash diets comes from the consumer advice center (as of 2022), while the regulations on physician oversight and informed consent come from the Genetic Diagnostics Act. Information on price, scope, sample type, and laboratory comes from mybody®x's product page, accessed on 11.08.2026. All sources were accessed and reviewed on 11.08.2026.
mybody®x Editorial & Expert Team
Laboratory diagnostics Nutritional science Blood analysis interpretation Nutrigenetics
This article was created by the mybody®x editorial and expert team. The team combines laboratory diagnostics, nutritional science, and the interpretation of blood analyses. Those who contribute to it are listed on the authors page.
Published on 29.01.2025 · Last updated on 11.08.2026
The content is intended for general information and does not replace medical advice, diagnosis, or treatment. Reference ranges depend on the laboratory, method, and age—the information on your test result is always authoritative.
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