Arm and leg fat
Arm and leg fat is an estimate of the fat mass stored in the limbs, that is outside the trunk.
Short answer
Arm and leg fat is the sum of fat in the four limbs, that is the part of total fat outside the trunk. It is useful as a ratio to total fat mass rather than as a standalone number, and it changes over months.
What the value represents
Total fat mass says how much fat there is. It does not say where it sits — and that is usually the question people bring to the result.
Arm and leg fat is the sum of the fat mass of both arms and both legs from the segmental analysis. The rest of the fat sits in the trunk, where it is further divided into subcutaneous and visceral.
On its own the value has no scale. It only makes sense relative to total fat mass: two people with the same kilograms of limb fat can have a completely different fat distribution.
- The sum of the estimated fat mass of the four limbs, in kilograms.
- The part of total fat mass that does not sit in the trunk.
- A counterpart to visceral fat area, which describes the opposite region — inside the abdomen.
- It does not represent the distribution of fat within a limb or the share of subcutaneous fat in it.
How the value is produced
- A derived value. It is the sum of segmental fat of the right and left arm and the right and left leg.
- Segmental fat itself is an estimate derived from the measured impedance of each segment, not a direct measurement of fat.
- On the visceral fat result sheet the value appears as one component of the weight breakdown: subcutaneous fat, visceral fat, fat outside the abdomen, limb fat and fat-free mass.
- The uncertainty of the segmental estimate carries into the sum, so the value is no more precise than its inputs.
How to read the current value
- The value is the sum of the fat mass of both arms and both legs; the manual defines it exactly that way, from the segmental fat analysis.
- On the visceral fat sheet it is one component of the weight breakdown alongside subcutaneous fat, visceral fat, fat outside the abdomen and fat-free mass.
- Read it together with total fat mass. On its own it shows only part of the fat and has no scale without the whole.
- The device also sends reference limits for trunk fat without the corresponding main value, so those limits have nothing to accompany on the result.
How to read change over time
- The distribution of fat between limbs and trunk changes slowly; follow it over months, not weeks.
- Read a change together with total fat mass. If limb fat falls while total fat holds, the ratio changed, not the amount.
- Short-term swings reflect measurement conditions just like other body composition estimates.
General principles: how to read change between measurements →
What to read it with
- Fat mass and percent body fat – the overall amount.
- Segmental fat – the same information broken down by segment.
- Visceral fat area – fat inside the abdominal cavity, which does not belong here.
- Segmental lean mass – the muscle side of the same segment.
Common misunderstandings
- Lower limb fat is not automatically a better result. It only means there is less fat in the limbs; where the rest sits is answered by comparison with total fat mass.
- It is not a value for losing fat from a specific body part. Fat cannot be removed selectively from arms or thighs by training them.
- It does not describe the shape or circumference of a limb. Circumference also includes muscle, bone and water.
- It is not the same as subcutaneous fat. Subcutaneous fat is the layer under the skin anywhere on the body, including the trunk.
What can affect the result short term
- Hydration and measurement conditions, because the estimate derives from body composition.
- Food and drink shortly before the measurement.
- Training shortly before the measurement.
- Time of day and the shift of fluids into the lower body.
What to do next
- Always read the value next to total fat mass and percent body fat. Kilograms alone have no scale.
- When following fat distribution, add visceral fat area and waist circumference — they describe the region this value excludes.
- Follow the trend over months and under comparable measurement conditions; fat distribution changes slowly.
- If limb shape interests you, follow segmental lean mass alongside fat. Together they describe what is actually changing in the segment.
What the value does not determine
- It determines no health condition and no distribution of fat within a limb.
- It is an estimate derived from the segmental analysis, not a measurement.
- Reference limits for trunk fat arrive without the corresponding main value, so there is nothing to relate them to on the result.
- It excludes trunk fat, so on its own it does not describe the total amount of fat.
On terminology
- The manual uses the label Arm/Leg Fat and defines it as the sum of segmental fat of both arms and both legs from the segmental fat analysis section.
In more depth, with sourcesIn more depth: why limb fat is counted separatelyExpand the detailed explanation
Segmental bioimpedance analysis measures the impedance of five segments separately and estimates the composition of each. Limb fat is then a plain sum of the segmental fat of both arms and both legs — not a separate measurement but an aggregation that inherits the uncertainty of each segment.
Splitting fat into limbs and trunk is meaningful because the two regions behave differently. The manufacturer manual works with a weight breakdown in which subcutaneous fat, visceral fat, fat outside the abdomen, limb fat and fat-free mass stand side by side; each component answers a different question about fat distribution.
The same limitation applies as to other segmental estimates: individual segments carry more uncertainty than whole-body values, because arms and legs make up a small share of total mass and their impedance is more sensitive to posture and electrode contact. A trend over time is therefore more reliable than a single result.
Sources
- InBody 970 Result Sheet Interpretation (ENG_A_211104) — InBody Co., Ltd.
On this page
Related values
Related articles
Where to find it
The Visceral Fat Analysis, circumferences and basal metabolic rate.
- Reviewed by
- MojeInBody content team
- Date
An InBody measurement is not a diagnostic tool. Results do not determine health status and do not replace a medical examination.
FAQ
Frequently asked questions
Answers to what people ask most often about this value.
Does lower limb fat mean I am losing weight the right way?
Not necessarily. The value only says how much fat is in the arms and legs. Whether the development is favourable is shown by comparison with total fat mass and with visceral fat area, which describe the rest.
Can I lose fat specifically from my arms or thighs?
No. Fat is lost from the whole body according to energy balance, not according to which part is trained. Resistance training of an area changes the muscle, not the location of fat loss.
Explanations make the most sense alongside your own trend.
The public guide is open to everyone. The client portal adds your own value, history and the context of a specific measurement.