Weight not going down: which values you should check
The essentials at a glance
There are four explanations for a plateau on the scale, and you can check three of them without laboratory tests. The most common is the measurement itself, because fluid and intestinal contents shift weight over several days more than any change in body fat. Energy balance comes next, followed—much less often—by a medical cause.
This article ranks the four explanations by frequency and shows, for each one, what you can check yourself. Whenever an institution cites a figure, it is given here with its name and year. Where no such figure exists, that is also stated.
You will first read what a plateau actually describes and when it should be medically evaluated. Next come energy requirements, measurement, three common explanations fact-checked, and the blood values that can actually say something about it. The limits are covered at the end.
What to expect in this article
1. What a plateau on the scale actually describes
2. When a plateau belongs in a doctor’s office
3. Why your requirements are lower than you suspect
4. Why the scale provides the least reliable number
5. Three common explanations fact-checked
6. Which blood values can explain a plateau
7. Comparing the explanations
8. What you will do over the next four weeks
9. How to measure your values at home
10. Limitations: what a blood test does not explain
11. What to start with this week
Frequently asked questions
Sources
What a plateau on the scale actually describes
The statement “the weight isn’t going down” rarely describes what it appears to describe. It usually describes an observation over a few days, and over a few days body weight is not a reliable measure.
An adult carries several kilograms of fluid, intestinal contents, and stored carbohydrates, and these components fluctuate daily. They change the number on the scale without any change in body fat.
A genuine plateau can therefore only be said to exist when two weekly averages at least three to four weeks apart are at the same level. Anything shorter is noise.
Key takeaway
A plateau exists only when two weekly averages several weeks apart are at the same level—not when the scale shows the same number on three mornings.
This distinction is not mere semantics. It determines whether you are addressing a problem or a measurement fluctuation—and in the latter case, every measure leads you in the wrong direction.
What the number on the scale consists of
The scale shows a total, not its composition. That total includes muscle, bone, organs, body fat, fluid, and the contents of the digestive tract.
Two of these components change within hours. Intestinal contents depend on when and how much you last ate, while fluid responds to salt, carbohydrates, and unaccustomed exertion.
Body fat, by contrast, changes on a scale that remains invisible from one day to the next. A moderate deficit produces a few hundred grams per week, and that amount is smaller than the daily fluctuation.
This leads to an uncomfortable insight. The number you read every morning contains the information you are looking for, but it does not contain it on its own.
Why a plateau after several weeks is normal
Even with a functioning plan, the curve does not progress evenly. It follows a staircase pattern, with weeks without visible change followed by periods in which several weeks' worth of progress becomes visible at once.
The reason once again lies with fluid. It temporarily offsets changes until it no longer does, and then the number appears to jump.
Anyone familiar with this staircase pattern does not stop during the flat phase. Anyone unfamiliar with it changes the plan precisely there and thereby loses comparability.
When a plateau belongs in a doctor's office
This chapter deliberately appears before all explanations. A text that places the criteria for stopping at the end fails to reach precisely the reader for whom they are intended.
The most common medical cause associated with weight is hypothyroidism. In countries such as Germany, approximately 5 in 100 people have this condition (IQWiG, 2024), and its symptoms include mild to moderate weight gain in addition to fatigue and dry skin.
Documented source
“An elevated TSH level in the blood may be a sign of hypothyroidism.”
Institute for Quality and Efficiency in Health Care (IQWiG)
Hypothyroidism, as of 2024
TSH stands for the hormone with which the pituitary gland stimulates the thyroid. When the thyroid becomes less active, the pituitary gland increases production to counteract this. That is precisely why an elevated level is an indication, not the opposite.
The signs that call for an appointment before taking any action
These signs should be medically evaluated
Weight gain without changing your habits
over several weeks, with no changes to eating or physical activity
Persistent fatigue lasting for weeks
that does not improve with sleep and rest
Marked sensitivity to cold and dry skin
newly occurring and without an identifiable cause
Changes in the menstrual cycle
that coincide in time with the change in weight
New medications
whose onset coincides in time with the plateau
A single sign means little on its own. The picture becomes noticeable when several occur simultaneously and persist for weeks.
Many people who research this topic have already visited a medical practice and returned dissatisfied. They are not naive; they are missing a data point, not a promise.
For them, this chapter is a reminder that a second appointment with a specific question often helps more than the first one without one. “I don’t feel well” leads to a different examination than “my weekly average has been unchanged for six weeks, and I’m tired all the time.”
Why Your Needs Are Lower Than You Suspect
The second most common explanation is misjudging one’s own needs. This happens because the breakdown of calorie needs looks different from what most people assume.
What Makes Up Calorie Needs
Average shares of total calorie needs
Source: Institute for Quality and Efficiency in Health Care (IQWiG), Causes of Obesity, as of 2022
Resting energy expenditure is the energy used for heartbeat, breathing, and body temperature. According to IQWiG (2022), it accounts on average for around 70 percent of total calorie needs, while movement and work contribute around 20 percent and digestion the remaining roughly 10 percent.
This leads to an uncomfortable calculation. The portion you burn through exercise is the second-smallest, and a single snack can offset it.
How Small the Difference Can Be and Still Have an Effect
IQWiG illustrates the scale of the effect, though in the opposite direction: Anyone who consumes 50 more kilocalories per day than they burn could theoretically gain around 2 kilograms over a year (2022).
Fifty kilocalories is a sip of juice or half a cookie. A difference of this size can neither be remembered nor estimated, which is precisely why a plateau lasting months is often not a mystery but an unnoticed small detail.
According to IQWiG, resting energy expenditure itself depends primarily on the proportion of muscle mass in body weight (2022). It therefore changes over months with training status, not over days with the meal plan.
Why Estimates About Food Are Almost Always Off
The second half of the problem lies on the other side of the equation. Energy needs can be estimated, and so can intake, and both estimates can deviate in the same direction.
This has less to do with self-deception than with the structure of everyday life. Much of what people eat happens incidentally: the leftovers from a child’s plate, the pastry at the office, the sip from a bottle in the car.
Then there are the portions. Oil in the pan, cheese on bread, and milk in coffee are rarely measured, yet these three in particular pack a lot of energy into a small volume.
That is precisely why this article ends with a record, not a bill. Writing things down makes visible what guessing systematically overlooks, and it takes less effort than any formula.
Why the scale provides the least reliable number
The scale measures everything at once: body fat, muscle, bone, fluid, and the contents of the digestive tract. If any one of these components changes, the number changes without affecting the others.
Fluid fluctuates the most. It responds to salt, carbohydrates, the menstrual cycle, and unaccustomed exertion, and this response masks the small changes that matter when losing weight.
How to weigh yourself meaningfully
Weigh yourself twice a week at the same time of day, preferably in the morning after getting up. Record the value and calculate the average at the weekend.
Only averages should be compared with averages, over several weeks. Two individual morning readings a week apart say nothing, no matter how conclusive they look.
It also helps to use a second measure that does not respond to fluid: waist circumference, measured at the same spot and likewise at weekly intervals. If your waist measurement changes while the scale stays the same, the plan is working.
What pushes the number up in the short term
Four factors can shift weight within one or two days without changing body fat. Knowing them prevents most misinterpretations.
Salt binds water. A salty meal in the evening shows up on the scale the next morning and disappears again over the following days.
Carbohydrates have a similar effect. They are stored as glycogen, a short-term energy reserve, and this reserve binds additional fluid. That is why someone who resumes eating normally after a low-carb phase sees an increase that is not a relapse.
For women, the menstrual cycle is another factor. During the second half of the cycle, the body often retains more fluid, making comparisons between two weeks more difficult. It is therefore more useful to compare the same phase of the cycle over several months.
Unaccustomed exertion works in the same direction. After a new training session, the muscles under stress respond with temporary water retention, which looks like a setback on the scale.
Why body-fat scales tend to increase confusion
Scales with body-fat analysis promise precisely the breakdown that is missing. However, they do not measure body fat; they estimate it based on the body's electrical resistance.
This resistance depends on water content. As a result, the displayed body-fat percentage responds to the same factor that already causes weight fluctuations, and both figures fluctuate together in the same direction.
We have no substantiated information from the reviewed sources about the accuracy of such devices in everyday use, so no figure is provided here. They can still be used sensibly: treat the displayed value as a trend over months, not as a snapshot.
Anyone tracking both at the same time has two fluctuating numbers instead of one. In this situation, waist circumference is the steadier measure because it does not respond to water content.
Chapter at a glance
The scale measures body fat, muscle, fluid, and intestinal contents as a single number. Fluid fluctuates the most and responds to salt, carbohydrates, the menstrual cycle, and unaccustomed exertion. The measurement becomes meaningful only as a weekly average over several weeks, supplemented by a second measure such as waist circumference, which does not respond to fluid levels.
Three common explanations fact-checked
The following three statements come up in almost every conversation about a plateau. All three contain a kernel of truth and nevertheless lead in the wrong direction.
Checked against the evidence
Common belief
“My metabolism is broken; nothing works anymore.”
Evidence-based
Resting energy expenditure accounts for around 70 percent of calorie requirements and depends mainly on the proportion of muscle mass in body weight (IQWiG, 2022). It is therefore a slowly changing factor, not a switch that can fail.
Common belief
“I just need to exercise more, then things will start working again.”
Evidence-based
Exercise helps with weight loss and has additional health benefits, but without adjusting the diet it is generally not enough for substantial weight loss (IQWiG, 2022). Physically active participants lost almost two kilograms more after twelve months.
Common belief
“Two more kilograms in one week means two kilograms of fat.”
Evidence-based
An average of just 50 kilocalories per day above requirements theoretically adds up to around 2 kilograms over a year (IQWiG, 2022). A change of this magnitude within one week therefore consists predominantly of fluid and intestinal contents.
The common mistake in these three statements is impatience. They explain an observation over days with a process that takes months.
Which blood values can explain a plateau
Once measurement and energy balance have been checked and the plateau persists for weeks, the question of lab values arises. Four are regularly mentioned in this context.
TSH as an indicator of thyroid function
The most important value is TSH. According to IQWiG (2024), an elevated TSH level in the blood may indicate an underactive thyroid, which affects approximately 5 in 100 people in countries such as Germany.
The key point is to set realistic expectations about the magnitude. IQWiG lists slight to moderate weight gain as a symptom, not substantial gain. Hypothyroidism therefore rarely explains the whole picture.
Cortisol, long-term blood sugar, and iron
Cortisol is the hormone produced by the adrenal cortex that rises under stress. It is measured in blood and provides a value at the time of sampling, not a daily profile.
Long-term blood sugar, abbreviated as HbA1c, describes the average blood sugar level over the past several weeks. It is one of the values that adds to the overall picture rather than providing an answer on its own.
A low iron store, measured as ferritin, does not explain weight. But it does explain fatigue, and fatigue reduces everyday movement—precisely the part of energy expenditure that already accounts for around 20 percent.
These values only form a picture when considered together. A single abnormal value is a data point, not an explanation, and its interpretation belongs in a medical practice.
Why a single value is rarely enough
Reference ranges depend on the laboratory, the method, and age. The same numerical value may be considered normal in one laboratory and borderline in another because the measurement methods differ.
Then there is the timing. Cortisol follows a pronounced daily pattern, and two values are comparable only if they were taken at the same time of day. A single value in the afternoon describes a different point on the same curve than one taken in the morning.
And finally, no laboratory value tells you why it is the way it is. It shows that the body is responding. Whether the reason is lack of sleep, a work situation, or an illness does not appear in any blood count.
That is why the order in this article is structured as it is. First the measurement, then the record, then the values—and the values always together with what you observed over four weeks.
What is deliberately omitted from this chapter
There are significantly more values circulating online than the four listed above. These include insulin, leptin, vitamin D, and the composition of the gut microbiome, each accompanied by the claim that they explain a plateau.
For none of these connections did we find documented information about weight change in the sources reviewed for this article. That is why they are presented here without a figure or recommendation.
This is not a statement against these values. It is a statement about what can be substantiated by the sources reviewed, and anything beyond that belongs in a conversation with a doctor rather than in an article.
How one of these values is assessed in detail is illustrated by the article on vitamin D deficiency and weight, which describes the pathway through fatigue and everyday movement.
The explanations compared
The three columns are arranged in the order in which they should be checked. The first is the most common, and the last the rarest.
| Criterion | Measurement and fluid | Energy balance | Medical cause |
|---|---|---|---|
| How to recognize it | The number fluctuates greatly over several days, but the weekly average still decreases | Two weekly averages four weeks apart are at the same level | Additional symptoms over several weeks, such as fatigue or feeling cold |
| What you can check yourself | Weigh yourself twice a week at the same time and measure your waist circumference as well | Write things down for two weeks without evaluating them, including beverages | Note symptoms and their timing; list medications |
| What a measurement contributes | Nothing; only the weighing method helps here | Little, because the record carries more weight than any laboratory value | A lot, because TSH and other values are the starting point here |
| Next step | Change the measurement method and wait four weeks | Evaluate the record and change one single thing | Appointment at a medical practice, with the record in hand |
The table is ordered by the sequence of checks, not by severity. We have no substantiated information about what proportion of plateaus is attributable to each of the three explanations, so none is provided here.
What you do over the next four weeks
Four weeks is the shortest period in which a plateau can be distinguished from a fluctuation. Anything decided before then is guesswork.
A plateau is not a finding but an observation that needs four weeks before it means anything.
A plateau is not a finding but an observation that needs four weeks before it means anything. During this time, you change exactly two things, and both concern measurement, not eating.
First, weigh yourself twice a week at the same time of day and calculate weekly averages. Second, write down what you eat and drink without changing or evaluating anything.
After four weeks, you have two comparable averages and a picture of your baseline pattern. Only then can you decide whether an adjustment or an appointment is needed.
The objection is valid: waiting four weeks feels like doing nothing. More precisely, it is the only activity that produces usable data, and without it every intervention starts from zero again.
What you decide after the four weeks
At the end of the four weeks, three things are available: two weekly averages, two circumference measurements, and one record. These lead to three possible conclusions.
If the weekly average decreases even though it did not feel that way, the problem was the measurement, not the plan. Then everything stays as it is, and only the weighing is continued.
If the average is available and your waist circumference has decreased, the plan is still working. This combination occurs particularly at the beginning of a change and is not a contradiction.
If both values are available and the record shows no explainable gap, the order is clear: first an appointment at a medical practice, then everything else. Bring the record and both averages; this will shorten the medical history.
How to determine your values at home
Two tests from mybody®x (MYBODY Lab GmbH) measure the values mentioned in this article from capillary blood obtained at home through a finger prick. Both include TSH, cortisol, and long-term blood sugar.
They help you prepare for a conversation at the doctor's office; they do not replace it. An abnormal value should be medically assessed, and the reference ranges on your own report are authoritative.
Blood test from capillary blood
Hormon & VitalCheck for Women
Nine biomarkers from capillary blood, including TSH, cortisol, prolactin, SHBG, folic acid, long-term blood sugar, and blood lipids, plus blood count values. What the test does not do: It does not provide a diagnosis, measures cortisol at only one point in time, and does not explain why your weight behaves the way it does.
Laboratory analysis 3–5 working days after receipt of the sample
Information from the product page, accessed 07.08.2026
Blood test from capillary blood
Hormon & VitalCheck for Men
Eleven biomarkers from capillary blood, including TSH, cortisol, testosterone, PSA, long-term blood sugar, creatinine, uric acid, eGFR, and blood lipids. What the test does not do: It does not replace medical evaluation, measures cortisol at only one point in time, and does not indicate what is causing a strain.
Laboratory analysis 3–5 working days after receipt of the sample
Information from the product page, accessed 07.08.2026
A measurement is useful once the four weeks of observation are behind you and the plateau persists. Before that, it provides a number without context.
Limitations: what a blood value does not explain
A laboratory value describes a condition, not a cause. It shows that the body is reacting, not what it is reacting to.
For the thyroid, this means specifically: An elevated TSH level may be a sign of hypothyroidism (IQWiG, 2024), and the associated outcome is slight to moderate weight gain. Anyone hoping this will explain twenty kilograms will be disappointed.
The tests themselves have the limitations stated on the product page. They measure one point in time, do not provide a diagnosis, and do not replace medical assessment.
And a boundary for our own part: We have no substantiated information on how often a plateau is attributable to an abnormal blood value. An estimate would be the worse error.
What to start with this week
Change how you weigh yourself before changing anything about your diet. Twice a week at the same time of day, record the values, and calculate the average at the weekend. It takes two minutes and replaces four weeks of guesswork.
At the same time, keep a record for two weeks of what you eat and drink. Without evaluating or changing anything. Be sure to include beverages, because in almost every record they are the biggest surprise.
It started with the observation that nothing was changing. After four weeks of careful measurement, you will know whether that is true. Often, that is the whole answer.
Frequently asked questions
When is a weight plateau really a plateau?
Only when two weekly averages, taken at least three to four weeks apart, are the same. Over a few days, weight fluctuates so much because of fluid and intestinal contents that small changes in body fat are lost in the noise. Therefore, weigh yourself twice a week at the same time of day and compare only average with average.
Could my thyroid be to blame if I cannot lose weight?
It could be part of the explanation. In countries such as Germany, around 5 in 100 people have an underactive thyroid, and its symptoms include mild to moderate weight gain (IQWiG, 2024). An elevated TSH level in the blood can be a sign of this. Interpreting the value belongs in a medical practice, especially if fatigue, sensitivity to cold, or dry skin also occur.
Why am I not losing weight even though I exercise?
Because physical activity accounts for the smaller share of calorie needs. According to IQWiG (2022), resting energy expenditure makes up around 70 percent on average, while movement and work account for around 20 percent. Exercise helps with weight loss, but without dietary adjustments it is generally not enough for substantial weight loss. In studies, physically active participants lost nearly two kilograms more after twelve months.
How much deviation in my eating is enough to keep my weight from changing?
Very little. The IQWiG calculates that just 50 kilocalories a day above your needs could theoretically mean around 2 kilograms of weight gain over a year (2022). Fifty kilocalories correspond to a sip of juice or half a cookie. A difference of this size cannot be estimated; it can only be made visible through a record.
Which values should I have checked if my weight has plateaued?
In connection with weight, the values most often mentioned are TSH as an indicator of thyroid function, cortisol as an adrenal cortex hormone, long-term blood sugar HbA1c, and the iron-storage protein ferritin. None of these values can explain weight on its own. Together, they provide only a picture, and that picture needs to be medically interpreted. Four weeks of careful observation should come before any measurement.
Next step
When you have completed four weeks of observation
If the plateau persists, the two hormone checks measure TSH and cortisol, along with long-term blood sugar, as a starting point for the conversation at your doctor’s office. They do not replace a medical evaluation.
Hormone & Vital Check for Women Hormone & Vital Check for MenRead more
You might also be interested in
A look at behavior and everyday life if you are less interested in the numbers and more interested in habits.
A single value explained in detail, through the lens of fatigue and everyday activity.
Sources
- Institute for Quality and Efficiency in Health Care (IQWiG): Underactive thyroid (hypothyroidism) (as of 2024) – gesundheitsinformation.de
- Institute for Quality and Efficiency in Health Care (IQWiG): Causes of obesity (as of 2022) – gesundheitsinformation.de
- Institute for Quality and Efficiency in Health Care (IQWiG): Weight-loss programs and medications (as of 2022) – gesundheitsinformation.de
- Institute for Quality and Efficiency in Health Care (IQWiG): Severe overweight (obesity) (as of 2022) – gesundheitsinformation.de
The verbatim quote about the TSH level comes from source [1], as do the figure of 5 in 100 people and the description of the symptoms. The breakdown of calorie requirements into approximately 70, 20, and 10 percent, the relationship between resting metabolic rate and muscle mass, and the calculation involving 50 kilocalories over one year come from [2]. The information about the contribution of physical activity after twelve months comes from [3], while the assessment of the importance of exercise comes from [4]. Information about price, biomarkers, sample type, and laboratory comes from the mybody®x product pages, accessed on 08/07/2026; processing times follow the central requirements for blood tests. All sources were accessed and reviewed on 08/07/2026.
mybody®x Editorial & Specialist Team
Laboratory diagnostics Blood analysis interpretation Nutritional science Nutrigenetics
This article was created by the mybody®x editorial and specialist team. The team combines laboratory diagnostics, blood analysis interpretation, and nutritional science. Contributors are listed on the authors page.
Published on 08/20/2026 · Last updated on 08/20/2026
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 report is always authoritative.
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