Short answer: you lower your body fat percentage by holding a moderate energy deficit over time while you keep strength training and eat enough protein. Keep the deficit under roughly 500 calories per day, research on training in a deficit shows that gains in lean mass disappear past that point, and aim for 0.5 to 1 percent of your body weight per week. From an average starting point, expect three to six months before the change is clearly visible. What decides the outcome is not how aggressive you are, but how much muscle you still have when you get there.
Plenty of people train hard, eat carefully, and watch their body fat percentage sit exactly where it was. The problem is rarely effort. It is usually a deficit that is either too large or not actually there, protein that is too low, and a measurement that is reporting water rather than fat.
This article covers what actually moves the number, which figures are realistic, and how to tell whether you are on track. The key claims are backed by published research so you can check where the advice comes from.
This article covers the fat half of the story. If you also want to build muscle at the same time, start with our overview of body recomposition, which sets out the four variables that together decide how your body composition changes. If you would rather not work it out alone, here is how English-speaking personal training in Amsterdam works.
What is a healthy body fat percentage?
A healthy body fat percentage runs roughly 8 to 25 percent for men and 21 to 36 percent for women, shifting upward with age. Women carry more essential fat by design, it supports hormone production and reproductive function, so the two ranges are not comparable to each other.
Body fat percentage is the share of your total body weight made up of fat mass. Everything else, muscle, bone, organs and water, is lean mass.
There is no internationally agreed standard. The ranges below come from work by Gallagher and colleagues, who linked body fat estimates to the established BMI cut-offs. They found that age, sex and ethnicity all shift what counts as healthy, and described their own ranges as provisional. Treat the table as orientation, not a verdict.
| Age | Women: healthy | Women: elevated | Men: healthy | Men: elevated |
|---|---|---|---|---|
| 20-39 | 21-33% | 33% and above | 8-20% | 20% and above |
| 40-59 | 23-34% | 34% and above | 11-22% | 22% and above |
| 60-79 | 24-36% | 36% and above | 13-25% | 25% and above |
Indicative, derived from Gallagher et al. (2000). Ethnic background shifts these ranges. This chart does not replace a clinical assessment.
Where the fat sits matters more than the percentage itself. Visceral fat, the fat packed around your organs, tracks far more closely with cardiovascular disease and type 2 diabetes than fat sitting directly under the skin, and that holds true even in people at a normal body weight.
How do you measure body fat percentage accurately?
No method you use at home will give you your true body fat percentage, but if you measure the same way every time, the trend it shows is reliable. The trend is the part you need.
A smart scale uses bioelectrical impedance: a weak current passes through your body and the resistance is converted into a body composition estimate. The European ESPEN guideline concludes this works reasonably well in healthy people with a stable fluid and electrolyte balance, while advising that results be interpreted with caution.
That stability caveat is the whole problem. A salty meal, a hard training session, alcohol, or where you are in your menstrual cycle all shift your fluid balance, and therefore your reading, while your fat mass has not moved at all.
| Method | Accuracy in absolute terms | Useful for tracking change | Practicality |
|---|---|---|---|
| Smart scale (BIA) | Low to moderate | Yes, under standardised conditions | Daily, at home |
| Skinfold calipers | Moderate to good | Yes, with the same practitioner | Needs a trained pair of hands |
| DEXA scan | High | Yes | Appointment, cost, infrequent |
| Tape measurements + photos | Gives no percentage | Very good | Free, no equipment |
Measure under identical conditions: morning, fasted, after using the bathroom, before you train. Then compare weekly averages rather than individual readings.
Do not dismiss tape measurements and photographs. They produce no percentage, but they show what is happening to your shape, which is what most people are actually asking about.
Does the type of diet matter, or only the deficit?
For fat loss, the size of the deficit matters far more than which macronutrient you cut. The DIETFITS trial randomised 609 adults to a healthy low-fat or a healthy low-carbohydrate diet for twelve months. Average weight loss was 5.3 kg versus 6.0 kg, a difference small enough that it tells you almost nothing about which diet to choose.
The same trial tested two popular explanations for why some people supposedly do better on low-carb: genotype pattern and baseline insulin secretion. Neither predicted who lost more weight on which diet.
This matters because much of the advice you will find on this topic is built on the opposite claim. If a page tells you carbohydrates are uniquely responsible for body fat, it is arguing against the largest randomised trial on the question.
The practical read: pick the eating pattern you can hold for six months without resenting it. Low-carb works well for some people because it reduces their intake without much effort, but the reduced intake is doing the work, not the absence of carbohydrates.
How big should your calorie deficit be?
Keep your deficit under roughly 500 calories per day if you want to hold on to muscle. A meta-analysis by Murphy and Koehler on resistance training under energy restriction found that gains in lean mass vanished once the deficit passed that threshold, even though strength gains largely survived.
An energy deficit means taking in less energy than you expend over a sustained period. Without one, fat mass does not fall, no matter how well designed your training is.
A bigger deficit does produce faster scale movement. But a worse share of that loss comes out of muscle, and every kilo of muscle you give up lowers your energy expenditure, which makes the whole thing harder to sustain.
You can build that deficit through food, through daily movement, or through both. For most people the combination is more comfortable, because it means eating less strictly.
How much protein do you need while cutting?
While in a deficit, roughly 1.6 to 2.4 grams of protein per kilogram of body weight per day is the working range. Outside a deficit the requirement is lower: a large meta-analysis by Morton and colleagues found no further gain in lean mass above about 1.6 g/kg.
A deficit pushes that requirement up. In a controlled trial by Longland and colleagues, two groups of young men spent four weeks in a substantial deficit with intensive training. The group eating 2.4 g/kg gained lean mass and lost more fat than the group eating 1.2 g/kg.
Protein also has the practical advantage of being comparatively filling, which makes a deficit easier to hold. Spread it across three or four eating occasions rather than loading it into one meal. The full breakdown by goal and age is in our article on how much protein you need.
A simple floor to work from: make sure every main meal contains an obvious protein source, such as eggs, fish, poultry, dairy, legumes or tofu.
Strength training or cardio: which lowers body fat faster?
Strength training determines what you lose; cardio mainly helps you create the deficit. Since body fat percentage is a ratio between fat and everything else, strength training is the more important of the two.
Lose weight without resistance training and you shed muscle alongside fat. Your weight falls, but your body fat percentage barely moves, numerator and denominator drop together.
Progressive overload means gradually increasing load, repetitions or sets so your muscles keep receiving a reason to adapt. Keep applying it during a deficit, even though the sessions will feel heavier than usual. Our article on progressive overload covers how many sets, how often and how heavy. This is also where coaching earns its place: in 1-on-1 personal training the load is adjusted week by week rather than guessed at.
Cardio and general daily movement still earn their place. Walking, cycling and simply moving more outside your sessions raise energy expenditure at a low recovery cost, which means you can eat less strictly for the same deficit.
How fast can you realistically lower your body fat percentage?
Expect around 0.5 to 1 percent of your body weight per week, and three to six months before the difference is obvious. At 80 kg that is roughly 400 to 800 grams per week.
There is a good argument for staying at the slow end. In a randomised study by Garthe and colleagues, elite athletes losing 0.7 percent of body weight per week lost as much fat as the faster group, and also gained lean mass, while the fast group gained none.
Your body fat percentage falls more slowly than your weight does. The first two weeks are largely water and glycogen: real on the scale, not yet fat loss.
The lower you start, the slower it goes. Moving from 25 to 20 percent is considerably easier than moving from 15 to 12 percent. A twelve-week block is a workable unit to plan around, which is how our 12-week programme is structured.
Why has your body fat percentage stopped dropping?
A stall almost always comes down to one of three things: intake has crept up, expenditure has fallen, or you are measuring something distorted by water. Usually more than one is in play.
Part of that falling expenditure is unavoidable. A lighter body burns less, and on top of that comes adaptive thermogenesis, a further drop in energy expenditure beyond what your new body weight alone would predict. This is well documented in the literature on the weight-reduced state.
What helps, in this order:
- Check the measurement. Compare this week's average against three weeks ago, not today against yesterday.
- Check intake. Log honestly for a week, including oils, drinks and the food you eat standing up.
- Add daily movement before cutting food further. Extra steps cost less recovery capacity than eating less.
- Take a maintenance period. Eat at maintenance for one to two weeks, recover, then resume.
What does not help: enlarging the deficit while you are already recovering badly. That costs muscle and makes the stall worse over time. If you cannot see where it is going wrong, a free intake session is usually enough to find it.
How much do sleep and stress actually matter?
More than most people assume, short sleep changes which tissue you lose, not just how much. In a controlled crossover study by Nedeltcheva and colleagues, participants held the same calorie deficit for two weeks with either 8.5 or 5.5 hours of sleep opportunity per night. On the short nights, the proportion of weight lost as fat fell by more than half, while loss of lean mass rose.
Participants also reported more hunger. Sleeping badly makes a deficit both less effective and harder to tolerate, and our article on how to sleep better covers what actually improves it.
Chronic stress pushes in the same direction: it makes eating behaviour less predictable and recovery slower. It is not a footnote next to nutrition and training, it decides whether those two can work at all.
In practice: seven to nine hours, a consistent sleep window, and training intensity that accounts for a demanding week rather than ignoring it.
Can you target belly fat specifically?
No, you do not get to choose where fat comes off. In a randomised study by Vispute and colleagues, participants did abdominal exercises five days a week for six weeks with diet held constant. Their abdominal endurance improved clearly. Their abdominal fat, skinfolds and body composition did not change.
Where your body releases fat is largely down to genetics, sex and hormones. In most men abdominal fat goes late; in many women the same is true of hips and thighs.
The encouraging part: visceral fat, the fat around your organs, responds well to an overall energy deficit combined with activity. That is precisely the fat most strongly linked to cardiometabolic risk, and our article on visceral fat covers how to screen for it and what reduces it.
Core work remains worth doing for strength, posture and trunk stability. It is simply not a route to lower body fat in that specific area.
When is body fat too low?
Your body fat is too low as soon as your body starts shutting functions down: flat energy, poor recovery, disrupted sleep, reduced libido, a missing or irregular menstrual cycle, or getting ill more often. This can begin before you reach any particular number.
The International Olympic Committee describes this as Relative Energy Deficiency in Sport: a syndrome in which sustained low energy availability affects hormonal function, bone health, immune function and mental health, in men as well as women.
Some body fat is essential. Below roughly 10 to 13 percent in women and 3 to 5 percent in men, there is no reserve left to draw on.
If you notice these signs, eating more is the correct response, not tightening further. Take persistent symptoms, and a missing menstrual cycle in particular, to a GP or sports physician.
Key points
- A deficit under roughly 500 calories per day protects muscle far better than an aggressive one, and yields more in the end.
- Target 0.5 to 1 percent of body weight per week; slower loss measurably protects lean mass.
- Eat 1.6 to 2.4 g of protein per kilogram of body weight per day for as long as you are in a deficit.
- Strength training decides what you lose; cardio and daily movement mainly help you build the deficit.
- Measure under identical conditions and judge weekly averages, a single reading tells you close to nothing.
Frequently asked questions
What body fat percentage do you need to see abs?
Visible abs typically appear around 10 to 12 percent body fat in men and around 18 to 20 percent in women. That threshold varies a lot between individuals, because where you store fat is genetically determined, and two people at an identical body fat percentage can look noticeably different. For women there is an added consideration: sitting below roughly 18 percent for extended periods is associated with hormonal disruption, so it is not a target to hold year-round.
Is 30 percent body fat a lot for a woman?
For a woman, 30 percent body fat sits inside the healthy range for most age groups. The commonly cited healthy band runs from roughly 21 to 33 percent for women aged 20 to 39, and shifts slightly upward with age. It reads very differently for a man, where 30 percent would be well above the typical healthy range. This is one of the reasons a single body fat number means little without knowing the sex and age of the person it belongs to.
What is the 30/30/30 rule for fat loss, and does it work?
The 30/30/30 rule is a popularised routine: 30 grams of protein within 30 minutes of waking, followed by 30 minutes of low-intensity cardio. The individual components are reasonable, since a protein-rich breakfast is filling and morning movement adds to daily energy expenditure, but there is no good evidence that this specific timing beats simply hitting your total protein target and your overall activity level across the day. Treat it as a structure that some people find easy to follow, not as a mechanism.
Do fat burners or supplements help lower body fat percentage?
Fat burners and fat-loss supplements make no meaningful contribution to lowering your body fat percentage. The effects found in research are small, short-lived or fail to replicate, and they are dwarfed by what a consistent deficit and regular strength training produce. Protein powder is the one worth keeping, but it is not a fat burner, it is just a convenient way to reach your protein intake.
My weight has not changed but my clothes fit differently. Is my body fat percentage dropping?
If your weight is holding steady while your clothes fit more loosely, your body fat percentage is almost certainly falling. You are losing fat mass while maintaining or building muscle, so total weight barely moves. This is most common in people new to strength training, and it has a name: body recomposition. Use tape measurements and photographs as your primary indicator during this phase.
Want the full picture, including how to build muscle at the same time? Read our overview of body recomposition. New to the city and working out how training here fits your routine? Read our complete guide to personal training in Amsterdam for expats.
Sources
Scientific claims in this article were verified via PubMed.
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