The key terms around weight trend, weight loss and body composition, each explained in one to three sentences. Every term has its own anchor and links to matching articles, calculators and topics.
Also: body mass index
BMI is body weight in kilograms divided by the square of height in meters. The WHO classifies adults below 18.5 as underweight, from 25 as overweight and from 30 as obese. BMI does not distinguish between fat and muscle and is therefore only a rough guide.
Read more: BMI healthy range by height: the table and what it missesBMI chart by heightWeight loss
Also: body fat
Body fat percentage states what share of body weight is fat. Body fat scales estimate it via bioelectrical impedance, which depends heavily on hydration, so single readings vary considerably. Here too, the trend over several weeks says more, complemented by waist circumference.
Read more: Water weight vs fat: how to tell what the scale is showingBulk & Cut
Also: recomp
Body recomposition means losing body fat and building muscle at the same time. Weight often stays almost the same, while waist circumference and body fat percentage go down. The scale alone therefore cannot show a recomposition.
Read more: Bulk & Cut
Also: energy deficit
A calorie deficit exists when, over a period of time, you take in less energy than your body uses. As a rough rule of thumb, 1 kg of body weight equals about 7,700 kcal, so a daily deficit of 500 kcal gives roughly 0.45 kg per week. Because energy expenditure drops as you lose weight, the pace slows over time at the same intake.
Read more: Calorie deficit calculator: why 7,700 kcal per kg misses your weekCalorie deficit and goal dateWeight loss
A dose marker is an entry in the weight history that records the date and new dose of a medication change, for example during GLP-1 treatment. It lets you compare the weekly rate before and after the change. The comparison shows a link in time, not a cause; your doctor decides on the dose.
Read more: Semaglutide weight loss timeline: what a normal curve looks likeGLP-1 medication
Also: Holt's method
Holt's double exponential smoothing smooths not only the level but also the slope of the weight curve. As a result, it lags less than a simple average during steady loss or gain and can be extended across gaps in the data. After a change of direction it can briefly overshoot.
Read more: How to Calculate Trend Weight: Four Methods and Which to ChooseTrend weight calculatorWeight loss
Also: calorie balance
Energy balance is the difference between energy taken in and energy used. If it is negative over weeks, the trend weight falls; if it is positive, it rises. The weekly rate lets you roughly work back to the average daily balance: 0.1 kg per week corresponds to about 110 kcal per day.
Read more: Calorie deficit calculator: why 7,700 kcal per kg misses your weekWeight loss
Also: exponential moving average, EMA
Exponential smoothing forms the new trend value from the previous trend value and a small share of today's reading. Older weigh-ins therefore lose influence gradually instead of dropping out of a window abruptly. Trendcurve uses it as the default method with a smoothing factor of 0.1.
Read more: How to Calculate Trend Weight: Four Methods and Which to ChooseTrend weight calculatorWeight loss
Also: carbohydrate stores
Glycogen is the storage form of carbohydrates in muscles and liver. Each gram of glycogen binds about three to four grams of water, which is why carbohydrate intake and training change body weight quickly. Much of the rapid loss in the first days of a diet is glycogen and water.
Read more: Water weight vs fat: how to tell what the scale is showingWeight Gain After a Workout: Why the Scale Goes Up After TrainingBulk & Cut
Also: corridor
A maintenance corridor is a range around the goal weight within which the trend weight should stay after losing weight, for example plus or minus 1.5 percent. As long as the trend stays inside, no action is needed; leaving it is an early signal. In Trendcurve you set the width yourself.
Read more: Weight loss
Also: 7-day average, 14-day average
A moving average is the mean of the most recent daily readings, for example over 7 or 14 days, shifting forward by one day each day. Every day in the window counts equally. The longer the window, the smoother the curve and the later it reacts to real changes.
Read more: Trend weight instead of the daily value: what a moving average really doesTrend weight calculatorWeight loss
Also: daily fluctuation, weight fluctuation
Noise is the fluctuation of the daily reading around the trend. It comes mainly from water, salt, glycogen, gut content, the menstrual cycle and sleep and can amount to 1 to 2 kg from one day to the next. On its own it says nothing about fat loss or fat gain.
Read more: Why your weight fluctuates every day - and why that is not a setbackWeight loss
Also: weight loss stall
A plateau is a phase in which the trend weight stops falling even though habits have not changed. Trendcurve calls it a plateau when the weekly rate stays below 0.1 kg per week for several days. A few days without change on the scale, by contrast, are usually just water.
Read more: Weight loss plateau or noise? How to read a flat trendWeight loss
Also: maintenance calories, calorie needs
TDEE stands for total daily energy expenditure: basal metabolic rate plus activity plus digestion. If you take in the same amount of energy on average, your weight stays stable. Formulas such as Mifflin-St Jeor give an estimate that becomes more accurate when you check it against your intake and trend over several weeks.
Read more: TDEE from your weight trendBulk & Cut
Also: weight trend, smoothed weight
Trend weight is a smoothed value calculated from daily weigh-ins, for example with a moving average or exponential smoothing. It filters out daily fluctuation and shows which direction body weight is really moving. A single outlier day shifts it only slightly.
Read more: Trend weight calculatorTrend weight instead of the daily value: what a moving average really doesWeight loss
Also: water weight
Water retention is extra water held in the body, for example after a salty meal, lots of carbohydrates, hard training, during the menstrual cycle or on creatine. It can raise the daily reading by a kilo or more within hours and usually subsides within a few days. Persistent or unusual swelling should be checked by a doctor.
Read more: Water weight vs fat: how to tell what the scale is showingBulk & Cut
Also: rate of loss, weight change per week
The weekly rate states how much the trend weight changes per week, for example minus 0.4 kg. Trendcurve calculates it as the slope of a regression line through the trend values of the last 14 days. It is the basis for forecast, target date and calorie estimates.
Read more: How fast should you lose weight? Realistic rates and what a plateau meansTrend weight calculatorWeight loss
The whoosh effect is a sudden drop in weight after a phase of apparent standstill, often overnight. What is established is that retained water can mask fat loss for weeks and the scale then catches up quickly; the popular explanation that emptied fat cells fill with water lacks solid evidence. In the trend weight a whoosh shows up as a small step, not a jump.
Read more: Weight loss plateau or noise? How to read a flat trendWeight loss
Also: weight regain after a diet
The yo-yo effect is weight regain after a diet, often back to the starting weight or beyond. A common reason is returning to old eating habits while energy needs have dropped along with body weight. A trend that rises over several weeks reveals the relapse earlier than single weigh-ins.
Read more: Weight loss
These definitions are for orientation and do not replace advice from a doctor or a nutrition professional.
Trendcurve shows trend weight, weekly rate and daily fluctuation from your own weigh-ins. Free, no account, all data on your device.