Weight Regain after Weight Loss (and how stop it)
- Nick T
- Sep 11
- 7 min read
Have you ever lost weight only to watch it creep back on, no matter how disciplined you've tried to be? Despite doing all the same things, a weight loss plateau still happens?
Well i'm here to tell you that it's not your fault. Unfortunately - and frustratingly - weight regain is VERY common. We're wired for it.
Your body has built-in systems that defend against weight loss. This is what we call metabolic adaptation: a suite of changes that make you hungrier and more energy-efficient after losing weight. Think of it as your body’s “power saver mode.”
Weight loss studies show that after intentional weight loss, most will experience regain of some or most of the weight lost within 2 to 5 years.
“…losing weight and keeping it off using willpower alone to reduce energy intake is difficult because considerable effort is required to persistently resist the physiological adaptations that act to increase appetite and suppress energy expenditure” Kevin Hall, PhD (NIH obesity and metabolism researcher)
This does not mean that our biology has doomed us to never lose weight and keep it off. But rather, that awareness of these mechanisms may help us set realistic expectations, plan for long term weight loss and be kind to ourselves when plateaus occur.
In this article we’ll delve into:
What metabolic adaptation actually is
Why movement is a BIG determinant of weight loss maintenance
How much exercise is needed to maintain weight lost
Genetic differences of weight management (Set Point Theory)
Common behaviours of successful weight loss maintainers
What metabolic adaptation actually is
Metabolic adaptation is the body’s natural response to weight loss. In the past, this helped humans conserve energy and nudge us to seek food, when availability was low. Today, the same response works, whereby weight loss is the famine, but world is now one of easy access to high‑calorie foods.
Metabolic Adaptation is a survival mechanism, and weight regain is NOT a failure. This is why leading experts frame obesity as a chronic, relapsing condition. Weight regain is anticipated, and ongoing research seeks to understanding how it can be minimised.
Below are the adaptations that occur in response to weight loss, generally greater than 10% of initial weight:
1) Your resting metabolism slows down more than expected
When you lose weight, your resting metabolic rate (RMR) - the calories your body burns just to keep you alive - drops. That’s expected, because a smaller body requires less energy to move around in the world. When RMR drops further than this expected amount, it's metabolic adaptation. This drop can be seen to persist for years after initial weight lost.
2) You burn fewer calories in your daily movement
After weight loss, the body adapts by becoming more efficient in movement.
It can also become more efficient at the cellular level. As a result, the same workout you used to do burns fewer calories than before.
More consistently seen, is a drop in non-exercise activity (NEAT), as the body subconsciously tries to conserve energy. Step counts may fall, and small movements like fidgeting occur less. These shifts can add up to hundreds of calories less burned each day.
3) Appetite ramps up & fullness signals weaken
Appetite regulating hormones shift in a way that increases the drive to eat. Leptin, the fullness hormone, goes down and ghrelin, the hunger hormone goes up.
Despite the best intentions, these biological shifts are powerful and often operate below conscious control. It becomes very likely that extra calories will creep back in, especially in today’s food environment where high-calorie options are always within reach.
Powerful Appetite Signals In an interesting study, researchers influenced unknown weight loss of Type II diabetes patients. The weight loss resulted in participants eating back, on average, an extra 100 cals/day per kg lost. They estimated this to be three times more than the drop in energy expenditure.
How much activity helps maintain weight loss?
Exercise alone isn’t the strongest driver of weight loss (as I’ve written about in this article), but it plays a very important role when it comes to keeping weight off long term.
Some analysis have found that to successfully maintain weight loss, upward of 250 minutes of moderate, or 125 minutes of vigorous exercise per week could be required.
Moderate Exercise: Walking briskly (4-6 kph) Recreational swimming Cycling slower than 16kpm Active forms of yoga (Vinyasa/Power) Gardening or active chores Vigorous exercise: Jogging / running Swimming laps Bicycling faster than 16kph Skipping rope Heavy yard work Vigorous classes From the Compendium of of Physical Activity
Why more exercise helps with weight maintenance
Intuitive to all of us - it boosts energy expenditure enough to balance out the powerful physiological drive to regain weight.
It offsets the powerful reduction in NEAT that happens after weight loss.
It could improve appetite regulation, helping avoidance of unintentional overeating and cravings for calorie-dense foods.
Weight Loss Set Points & Different Body Types
Weight loss and metabolism experts believe that we each have a weight range, or Set Point that our body “defends.” Push below it, and the weight regain mechanisms ramp up. It’s also been seen in the opposite direction, where some people burn off extra calories without realising.
You know that person! The one we all hate. Who can whatever they want and don’t put on a pound.
We’re all very different in the way our metabolism adapts to energy changes. We could classify them into two main phenotypes:
Thrifty: Large drop in calorie burn when in a calorie deficit, and less increased burn when in a surplus → Harder to lose weight and keep it off
Spendthrift: Also known as the "hard gainer". Minimal drop in calorie burn when in a calorie deficit, and burn a lot more when in a surplus → Hard to gain weight and likely to lose weight after gain.
Varied Metabolic Changes: Researchers overfed healthy adults about 1,000 extra calories a day for two months. The outcome was very different from person to person. Some stored a large amount of those calories as fat, while others burned most of them away. The difference came down to how thrifty they were with NEAT.
Important to keep in mind, though, is that biology isn’t the whole story. The thrifty vs spendthrift model remains a crude simplification.
Our environment, with easy access to high-calorie foods, large portion sizes and little daily movement shapes where our body weight might settle.
Our biology may attempt to defend a weight range, but our surroundings encourage weight regain by nudging that range higher.
How to stop weight regain after weight loss
As I mentioned earlier, we are not DOOMED to never lose weight and keep it off. Now that we understand what’s happening under the hood, we can plan the weight loss process, set realistic expectations and think about the plan after the plan.
Below are actions that you can take during and after the weight loss phase to ensure long term sustainable weight loss:
Plan for maintenance from the start Maintenance of weight loss is a phase in itself that should be anticipated and planned for.
You now know the inner workings of weight regain, which means you can initially decide on how you approach your weight loss phase, and the habits to establish for the maintenance phase.
Set realistic weight loss goals Big health benefits come from losing just 5 to 10% of initial weight. Once you’ve reached this, aim to maintain it for 6 to 12 months before deciding on further weight loss.
Shift away from the need for large weight loss goals, which are often more challenging to maintain.
Expect plateaus and small regains Weight loss is not linear. Accepting that plateaus or regain will occur is very important. This way we don’t get disheartened, and give up on our efforts, when we know it’s part of the process.
Regular weigh-ins help catch small gains early Successful weight-loss maintainers regularly weigh themselves to catch upward trends, reflecting and tightening their habits to prevent regain.
Try not to react to daily weight fluctuations, but rather weekly trends.
Establish an exercise routine that’s sustainable and enjoyable Use your weight loss phase to get into a regular exercise routine. Unless you already LOVE exercise, make sure it’s an enjoyable form and make some of it low impact, so that you can build up to larger amounts over time.
Move more than the minimum Build up to 200–300 minutes/week of a mix of moderate and vigorous movement. Remember injury risk is high when going from little to lots.
Our body’s need to build tolerance to new forms of exercise gradually. Split intense sessions with moderate/low impact sessions or rest days.
Protect your muscle At least twice per week, during both weight loss and maintenance phases, lift weights to maintain muscle mass and promote body fat loss. It may help to curb the metabolic slow down.
Hit your protein targets Protein helps in many ways:
Increases the thermic effect of food (more energy burn through digestion)
Supports the retention of muscle mass with a well planned weight training program (see Work with Me)
Keeps you feeling fuller for longer.
Keep an eye on your steps If you wear a smart watch or pedometer, keep an eye on your steps.
At best, increase steps to contribute to more movement.
At worst, identify drops in step count, which could be an indicator of decreased NEAT.
Shape your environment Appetite signals stay elevated for a long time. Make your defaults work for you:
Stock more whole foods and lean protein.
Keep hyper-palatable snacks out of reach.
Build routines early for meals, activity, and sleep.
Frame your motivation Internal motivation is far more effective for long-term behaviour change than external motivation.
eg) Exercising just to see the number on the scale drop (external) is less likely to sustain daily efforts than believing deeply in exercise’s importance for your longterm health & function (internal).
Read my Guide - Nutrition Fundamentals for Health & Weight Loss For a practical, evidence-based approach to weight loss and long-term maintenance. It covers habits like hitting protein targets, managing hunger, and creating a food environment that works with your lifestyle.
The Bottom Line
Your body is designed to defend its weight after loss. Metabolic adaptation lowers burn and raises appetite for at least a year, often longer.
That’s why long-term success relies less on “perfect” dieting and more on durable systems:
Regular movement
Muscle-preserving habits
Protein-forward eating
Routine monitoring with adjustments
An environment that lowers the need for willpower