Most weight-loss plans have a clear start and a clear finish.

Start the diet. Hit the target. Done.

But for most people, the hardest part isn’t losing the weight. It’s keeping it off.

How Common Is Weight Regain?

A large meta-analysis published in the BMJ in January 2026 pooled 37 studies with more than 9,300 people who had used weight-loss medication.

After stopping the medication, people regained an average of about 0.4 kg per month. At that rate, they were projected to be back at their starting weight in around 1.7 years. Improvements in blood pressure and cholesterol were also projected to disappear within about 1.4 years.

Regain was also faster after stopping medication than after behavioural weight-loss programmes (diet, exercise and habit coaching), where people had learned skills they could keep using.

The lesson isn’t that weight-loss drugs are bad. It’s that once the thing producing the weight loss stops, the weight tends to come back. That applies to medication, and it applies just as much to a strict diet you can’t keep up forever.

Your Body Pushes Back

Regaining weight isn’t simply a lack of discipline.

In a well-known study, people who lost an average of 13.5 kg on a very low-calorie diet still had higher levels of ghrelin (a hunger hormone) and reported feeling hungrier a full year later.

In other words, after weight loss your body actively nudges you to eat more. That’s normal biology, not a personal failure. But it does mean you need a plan for it.

Treat Maintenance as Its Own Goal

Most people treat maintenance as “going back to normal” once the diet is over. The trouble is that “normal” is usually how the weight was gained in the first place.

A better approach is to treat maintenance as a separate phase with its own goal: keeping your weight within a small range (for example, within 2 kg).

Interestingly, one randomised trial had people practise maintenance skills before losing weight. Both groups lost the same amount of weight, but the group that learned maintenance first regained less than half as much over the following year (about 1.5 kg vs 3.3 kg).

What Successful Maintainers Do

The US National Weight Control Registry tracks people who have lost weight and kept it off. Common habits include:

High levels of physical activity: often around an hour a day, much of it walking.
Regular self-monitoring: weighing themselves regularly so small gains get caught early.
Consistent eating patterns: similar habits on weekdays and weekends.
Regular meal structure: most eat breakfast and have a predictable routine.

These come from people reporting what they do, so they don’t prove cause and effect. But they line up well with what we know from controlled trials.

A Simple Maintenance Plan

Set a range, not a number: pick a weight range and act early if you drift above it.
Keep strength training: preserving muscle makes the new weight easier to sustain.
Keep the habits that worked: protein at most meals, plenty of fibre, regular activity.
Increase calories gradually: add food back in steps rather than all at once.
Have a reset plan: if you go above your range, go back to the basics for a few weeks. No panic, no crash diet.