Working out but not losing weight (but losing inches)?

You have been training for more than a week, and the scale still shows almost the same number. That does not mean it was wasted. In a 2026 study, 16 adults walked under supervision for 12 weeks, and their weight barely changed — while fat mass fell, fat-free mass rose, and MRI visceral fat fell by about 10%. On average the body offset about 39% of the energy the exercise used, and people differed a great deal. None of that says you are not trying hard enough.

Losing inches while the scale stays put can come from the same mix: less fat, a little more fat-free mass. In that study even the tape around the waist barely moved, so a flat tape is not proof of failure either.

In short: judge the month by more than the morning weigh-in, keep ordinary movement on training days, add some strength work, and if fat loss is the goal, keep a modest deficit. Give it at least 12 weeks before you decide the whole thing is pointless.

What did the 16-person walking study actually find?

Knaan and colleagues studied 16 sedentary adults, BMI 25–30, age 21–45, 8 of them women. For 12 weeks they walked under supervision, about 200 minutes a week, at 65–75% of maximum heart rate. There was no control group. The same paper includes mouse experiments; what follows is about the people only.

Where the energy went:

• On average the body compensated for about 97 kcal a day, about 39% of what the exercise cost. The spread is huge (standard deviation ±116%), and that is the main result: 11 of the 16 compensated, 5 did not.
• Resting metabolic rate was 74 kcal a day lower, sleeping metabolic rate was lower than predicted, and walking became more economical.
• Daily moderate-to-vigorous activity rose only about 15 minutes, although the walks alone were expected to add about 28.
• Measured intake did not change, while what people wrote down came out about 430–580 kcal a day lower than it actually was.
• Liver and kidney volume fell about 4–5%.

(Knaan et al., Communications Medicine, 2026)

This is one small study without a control group. It shows that a flat scale and a real change in fat can happen together. It does not name your personal percentage.

Is the body “cancelling” exercise, or not?

Two recent papers, a 2026 review and a 2025 analysis, contradict each other.

Pontzer and colleagues, in a 2026 review in Current Biology, argue that aerobic training raises total energy expenditure by less than an additive model predicts. In their synthesis, compensation was smaller when the training was resistance work, and larger when aerobic exercise was combined with eating less. Pontzer et al., Current Biology, 2026.

Howard and colleagues, in PNAS in 2025, looked observationally across a very wide activity range, including ultrarunners. They report a linear relationship between physical activity and total energy expenditure, and no evidence of a constraint. Howard et al., PNAS, 2025. The debate is not closed, and it is not worth picking the paper you like better.

What is useful whichever side is right: in the walking study the scale missed the fat loss because fat-free mass rose at the same time; the body compensated for part of the new load; and people did not fully keep the rest of the day’s movement. You can track those things in yourself, and they have nothing to do with willpower.

What to check before you decide it is not working

The scale, over weeks rather than one morning. Water, a late dinner, a new session, and a menstrual cycle all move the number. How to read that noise is in why the scale jumps. If the weight has been stuck for several weeks running, the article on a weight plateau is the one to read.

Waist, clothes, stairs. In the same 16 people, waist and hip did not move while visceral fat did. A tape can miss a change. It can also show one the scale hides when you are adding muscle. Use both, and do not make either a verdict. The visceral-fat trials, and why the tape is a rough proxy, are in exercise and visceral fat.

A body tape with a lock makes the waist number less dependent on how hard you pulled. The MyoTape body tape measure (ASIN B000G7YW7Y) is one inexpensive option. As an Amazon Associate, Lean Wisely earns from qualifying purchases. Once a week, same spot, same time of day, is enough.

Ordinary movement on training days. In the study, moderate-to-vigorous activity rose by about half of what the walks should have added. In real life that looks like a hard session and then the sofa until evening. Walking to the shop is movement too, and it counts.

Strength work, if you only do cardio. The Pontzer summary links less compensation to resistance training. That does not promise anything to you personally, and the argument is not settled. Lifting still changes what the scale is made of. A short version is the beginner home workout.

Food, from a log rather than from memory. Measured intake did not fall, while what people wrote down came out hundreds of kilocalories a day lower. If you are sure you are in a deficit because the day “felt light,” the feeling is misleading. Try a rough log for a few weeks, then you can stop: counting calories and calorie deficit in plain language. You want a modest deficit, not a hungry week.

Give the plan 12 weeks, and do not blame yourself

The walking study itself lasted 12 weeks. Two weeks of a new gym is mostly water, soreness, and a schedule you have not learned yet. If fat loss is the aim, keep the deficit small enough that you still train, and keep the training small enough that you still move the rest of the day. If you are not sure your walks are even moderate, the talk test answers that for free; a chest strap is optional.

Nothing in these numbers says you are lazy, broken, or “bad at fat loss.” Eleven people compensated for part of the load, five did not. You cannot tell which group you are in from one stubborn morning. You can check whether the week you lived matches the week you planned.

What to do for the next twelve weeks

1. Weigh under the same conditions, and look at the week, not Tuesday against Friday.
2. Once every two weeks, note the waist and whether a repeated effort (the same stairs, the same walk) feels easier.
3. On training days, do not cancel the ordinary things you do on your feet — the same walk to the shop.
4. Add two short strength sessions if the week is only cardio.
5. If you want the scale to fall, keep a modest deficit you actually calculated, not one you are guessing at.
6. Decide at week 12, with those notes, whether to change food, change training, or keep going. Do not decide on day 10.

In short

A flat scale after you start exercising can mean less fat and more fat-free mass, plus a body that offsets part of the new work. The 16-person study is too small to be your forecast, and the constrained-versus-additive argument is not finished. Watch more than the scale, keep moving on training days, add strength work, keep a calculated modest deficit, and give it at least 12 weeks rather than two.

Common questions

I exercise every day and the weight is the same. Should I train harder?

Not as the first move. In the walking study, other daily activity rose less than the added walks, and intake did not fall. A harder session that wipes out the evening walk and makes dinner larger can widen the gap you are trying to close. Check the week of steps and the week of food before you add intensity.

Does this mean exercise does not help weight?

It means exercise does not have to show up as a weekly drop on the scale to be changing fat, fitness, and visceral fat. In that small study, fat fell and the scale did not. If the goal is a lower scale, exercise still needs a gap between intake and use. The gap is the deficit, not a punishment.

How long is long enough?

The study this rests on lasted 12 weeks. Use that as a minimum before you call the plan a failure. One week is weather, not climate.

Sources

• Knaan et al., Communications Medicine, 2026: 16 adults, 12 weeks of walking, no control group. Weight unchanged, fat down, fat-free mass up, visceral fat about 10% lower, compensation about 39% with a very wide spread. PMID 41814067.
• Pontzer et al., Current Biology, 2026: review arguing for constrained total energy expenditure. Compensation smaller with resistance training, larger when aerobic work is paired with diet restriction.
• Howard et al., PNAS, 2025: observational, wide activity range including ultrarunners. Linear activity and total expenditure, no evidence of constraint. The counter-view.