Why the Last 5 to 7 Kg Is the Hardest to Lose: The Science

Two hikers on the last uphill stretch of a mountain path at sunrise

The last few kilos are hard for an unglamorous reason. You are now a smaller body, so you burn less, while your brain reads shrinking fat stores as a shortage and turns the hunger up. The deficit that worked at your starting weight is no longer a deficit. Nothing about you is broken.

Listen to this article, about 10 minutes. A synthetic voice reads the article and announces each section title as it begins; tables are read row by row and the questions at the end are left out.

Recorded 10 October 2026 from the article as published that day. Press a chapter to jump there; the highlighted line is what is playing. A play button sits beside every section heading, and once you scroll past this player a bar at the bottom of the screen keeps the controls in reach. Tap or click any sentence to hear the reading start from there.

On this page: a diagnostic table of common fat loss myths, scientific figures from clinical trials, and a practical checklist to help you adjust your strategy.

Think you already know this? Five questions, one minute.

Every answer is on this page. Answer from what you know now; the page fills in the rest.

  1. 1. Which of the following is a key reason fat loss naturally slows down as your body weight decreases?

  2. 2. What is the term used to describe the body becoming thriftier with energy expenditure during weight loss?

  3. 3. Which hormone produced by fat tissue decreases as fat mass falls, signaling the brain to increase hunger?

  4. 4. Why does your waistband often improve before you notice changes in the mirror?

  5. 5. What does the British Heart Foundation suggest doing when you experience a weight loss plateau?

Everyone recognises the shape of it. The first stretch goes beautifully. Clothes loosen, people notice, the scale behaves. Then somewhere in the final 5 to 7 kg the whole thing turns to treacle, and the internet arrives right on cue with a tea, a berry and a man in a gilet explaining that your metabolism is broken.

It is not broken. This phase is well mapped, and the real mechanisms are duller than the ones being sold to you. They are also the only ones you can act on.

Why does fat loss slow down exactly when you want it to speed up?

Because slowing down is what the curve does. A clinical review of weight loss plateaus on the NIH Bookshelf describes plateaus as occurring weeks to months after a programme starts, with people typically reaching maximal weight loss at around six months and then holding or slowly regaining. With weight loss medication the plateau usually lands between six and twelve months. A stall near the end is the expected shape of the graph, not a plot twist. For a stall at any stage, the measured size of each cause is set out in our breakdown of what is really behind a weight loss plateau.

Three ordinary things arrive together, and they compound:

  • A smaller body costs less to run. Fewer kilos to move, heat and maintain means fewer calories burned doing exactly the same day. That part is arithmetic.
  • The gap closes from both ends. A deficit calculated for your old weight quietly becomes maintenance for your new one, without you changing a thing.
  • Adherence drifts, invisibly and without malice. Portions creep, the tracking gets approximate, and a fortnight of weekends can flatten a fortnight of weekdays.

Is your metabolism damaged, or just smaller?

Mostly smaller, with a genuine extra on top. The measured effect is called adaptive thermogenesis: resting energy expenditure falls by more than the loss of tissue alone predicts. The body gets thriftier, not defective.

Hands arranging a precise portion of walnuts, illustrating metabolic adjustments when the last 5kg hardest to lose.
A smaller body requires fewer calories, making portion awareness key to progress.

The study everybody quotes here followed contestants from a televised weight loss competition. Six years on, Fothergill and colleagues reported in Obesity that participants had lost an average of 58.3 kg during the 30 week competition, that resting metabolic rate had fallen by an average of 610 kcal a day by the end of it, and that six years later they had regained around 41 kg while resting metabolic rate sat about 704 kcal a day below baseline.

Those numbers deserve a caveat rather than a headline. That was fourteen people on an extreme protocol, losing an extreme amount at extreme speed, and researchers still disagree about how much adaptive thermogenesis persists in someone dieting at an ordinary pace. Expecting a 700 kcal penalty because a television competition produced one is borrowing somebody else’s worst case.

What gets blamedWhat is usually going onWhat that changes
“My metabolism is broken”Resting burn falls with the smaller body, plus a modest extra that varies a lot between peopleRecalculate the deficit for the body you have now, and protect muscle while you do it
“I have no willpower”Appetite signalling genuinely shifts as fat mass falls, and it stays shiftedBuild meals around protein and fibre rather than trying to out stubborn your own hormones
“I need more cardio”The same session burns less at a lighter weight, and unplanned daily movement quietly dropsGuard daily steps and add resistance work, rather than stacking more punishment sessions
“My calories have not changed”Portion creep and untracked extras are the most common single explanation for a stallWeigh and log honestly for two weeks, as a diagnostic, not as a life sentence
“It is stubborn fat”Fat depots do behave slightly differently, but no depot ignores an energy deficitStop paying for anything that claims to target one area
“I need a detox”Nothing detoxes fat. Your liver and kidneys had that covered before the tea existedSpend the money on food you will actually eat and sleep you will actually get

Why does hunger get louder the closer you get?

๐Ÿง  Because the brain is running a survival programme that never got the memo about jeans. Leptin, produced by fat tissue, tells the brain that reserves are adequate. As fat mass falls, leptin falls with it, and the brain responds the way it would to a genuine shortage: more hunger, more food noticing, less spontaneous movement.

This is not a mood that passes. In a trial of 50 people with overweight or obesity who lost an average of 13.5 kg on a ten week very low energy diet, Sumithran and colleagues found in the New England Journal of Medicine that a full year after the diet ended, leptin was still around 35 percent below baseline while ghrelin and self reported hunger remained elevated. The appetite that turns up in month eight is not a character defect arriving on schedule. It is physiology, and it can be planned for.

Is the last fat actually different fat?

A little, and less than you would hope. Fat in different parts of the body does respond somewhat differently to the signals that release it, and visceral fat around the organs tends to shift earlier than the subcutaneous fat you can pinch. That is why the waistband often improves before the mirror does.

What does not follow is that you get to choose the withdrawal account. Spot reduction still does not work, however the device is marketed. The area that irritates you at the end is usually just the area that carried the most to begin with, and it answers to the same energy balance as everything else. There is more in our guide to what actually burns belly fat.

Is a set point quietly holding you back?

This one deserves an honest hedge. The evidence that the body defends a weight range is strong: that is what the leptin, hunger and energy expenditure findings describe. The evidence for a single fixed number written into you at birth is much weaker, and many researchers prefer the idea of a settling point that moves with what you eat, how you live and how long you have lived that way.

The practical version is the same either way. Push far enough below where your body has been sitting and the defence gets noisier. The useful question stops being “how do I force this” and becomes “what could I keep doing for a year without hating it”.

What actually helps when the last few kilos will not move?

A man organizing fresh meal prep containers, demonstrating strategies when the last 5kg hardest to lose.
Consistent planning and dietary variety help break through stubborn weight loss plateaus.

๐Ÿงฉ Nothing here is exotic. It is the same set of levers, applied to a body that has changed since you last did the sums.

  • โœ… Redo the maths for your current weight rather than the weight you started at.
  • โœ… Add resistance training, because muscle is the tissue doing a good deal of the burning and it is the tissue an aggressive deficit takes first.
  • โœ… Anchor meals on protein and fibre, which do more for satiety per calorie than almost anything else on the plate.
  • โœ… Watch daily steps as closely as workouts. Unplanned movement is the part that slides without you noticing.
  • โœ… Treat sleep as part of the plan rather than the thing you sacrifice for the 5am session.
  • โœ… Ask whether holding this weight for six months would beat losing more and rebounding past it.

And the levers that reliably do nothing:

  • โŒ Cutting harder. A bigger deficit at this stage mostly buys muscle loss and a louder appetite.
  • โŒ Adding cardio on top of everything else, while eating less, while sleeping badly.
  • โŒ Detox teas, fat burning wraps, and anything promising to melt one specific area.
  • โŒ Weighing daily and treating normal water fluctuation as a verdict on your character.

A plateau of a couple of weeks is usually noise. The British Heart Foundation makes the same point: a stalled scale after a period of steady loss is normal, and it is worth checking the simple explanations before assuming something has gone wrong with you.

Adjust Your Strategy for the Final Kilos

If your progress has stalled, use this checklist based on the article’s recommendations to safely audit your current routine.

Ticks are saved on this device only.

When is a stall worth taking to a doctor?

Some of these are worth raising with a GP or a registered dietitian rather than solving alone. Speak to a professional if weight that will not move comes with fatigue, feeling cold, hair or skin changes, or changes to your periods. The same applies if you take medication known to affect weight, if you have a thyroid condition, PCOS or prediabetes, or if you have a history of disordered eating.

If thoughts about food, weighing or restriction are taking up a large part of your day, that is a reason to seek help early rather than late. The NHS has practical guidance on managing your weight, including how to get support through your GP.

๐ŸŒฑ The last 5 to 7 kg are not a test of how badly you want it. They are a smaller body, a louder appetite and a set of sums that changed while you followed the old plan. Redo the sums, protect your muscle, sleep, and allow far longer than the first phase took. That is the whole trick, and it is gloriously unsellable, which is exactly why somebody is trying to sell you something else.

Frequently asked questions

Is a weight loss plateau normal, or a sign I have done something wrong?

It is normal. Clinical reviews describe plateaus arriving weeks to months into a weight management programme, with maximal loss commonly reached around six months. A stall is the ordinary shape of the curve rather than evidence of failure.

Will eating even less restart the loss?

Sometimes briefly, and usually at a cost. Deeper cuts at this stage tend to take more muscle, raise appetite further and become harder to sustain. Recalculating a modest deficit for your current weight is more reliable than cutting harder.

Do diet breaks or refeeds help at this point?

The evidence is mixed and the protocols in studies vary widely, so no single schedule can be claimed to work. Some people find a planned period at maintenance easier to sustain and easier to return from, which matters more than any hormonal claim made for it.

Does strength training help if the scale is not moving?

It helps in ways the scale is poor at showing. Resistance work defends muscle during an energy deficit, and muscle is metabolically active tissue. Waist measurements, how clothes fit and what you can lift often improve while the number holds still.

Why does hunger get worse the leaner I get?

As fat mass falls, leptin falls and ghrelin rises, and research has found those changes still present a year after a diet ended. Stronger hunger near the end is a physiological response, not a lapse in discipline.

How long should the last few kilos take?

Longer than the first few, and nobody can honestly give you a number for your body. General guidance for weight loss overall sits at roughly half a kilo to a kilo a week, and the final phase usually runs slower than that. A doctor or dietitian can help you set a realistic pace for your own situation.

Finished the page? The same five questions from the top, to see what stuck.


This article is general information, not medical advice, and is not a substitute for care from a qualified healthcare professional. Speak to your doctor about your own situation.

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4 responses to “Why the Last 5 to 7 Kg Is the Hardest to Lose: The Science”

  1. […] Why the Last 5 to 7 Kg Is the Hardest to Lose: The Real Science Behind Stubborn Fat […]

  2. […] The same literature is blunt that the 3,500 figure is a reasonable approximation for modest changes in people who are overweight, and an overestimate in others. So the arithmetic above is being generous to the five pound claim. Run it through a model that accounts for adaptation and the required deficit gets worse, not better. It is also a large part of why the tail end of any attempt feels different from the start, covered in why the last few kilograms are the hardest. […]

  3. […] the area someone is watching most closely, which means it is the area where slow change is noticed. Why the last few kilos are the hardest covers the parts of that feeling which do have a physiological […]

  4. […] The second is how readily that fat comes back out. Fat in the hip and thigh region, called gluteofemoral fat, is measurably slower to release its contents than abdominal fat. Work from Oxford using direct measurement in living tissue found femoral fat markedly resistant to adrenaline, with lower blood flow and a blunted release of fatty acids compared with the abdomen. The depot behaves as long term storage rather than day to day fuel. That is the mechanism behind the feeling that thighs are last to change, and it overlaps with what makes the final few kilograms so stubborn. […]

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