The Science Behind Weight Loss Plateaus: Why They Happen and How to Deal

Something that get’s a lot of dieters down, so down that it often needlessly puts an end to a diet. Why they happen is probably pretty variable from person to person and there’s also no clear answer on the cause. In theory the body is a furnace that burns food and stored energy in a very predictable way. That is true for the most part but weight loss plateaus are also a common occurrence too so much so that scientists have studied it. So let’s dive into the literature and find out what they, why they happen and what you can do about it!

What are they

Weight loss plateaus are pretty much what they sound like. After a period of losing weight adhering to a specific plan that has been working and then for no apparent reason you stop losing weight. Well take comfort at least that it is a real known thing so much so that scientists have even studied it. They occur across different diet plans and really they can happen at any time. That said there are a few known ‘hotspots’ in weight loss journeys for plateaus to happen. Some researchers have found clusters of plateaus at 11% of body weight (Chaput et al, 2006) and at 6 months of diet duration (Headland et. al, 2016). At the bottom of this article I’ve listed some other science of weight loss articles I’ve written you might want to check out.

Why do they happen

No one really knows exactly why plateaus happen exactly but there are plenty of theories. Insufficient evidence exists to say which of these factors explains plateaus so chances are that many of these theories explain at least parts of it. The first theory is that your behaviors are to blame. This is also closely tied to the willpower theory. The idea here is that after an initial high willpower period where you are strictly adhering to your plan you start to drift. Things like not tracking your calories as strictly, sneaking in treats, drinking more and or slacking at the gym. The idea here is that you need to be strict with yourself in order to break through your plateau. Be honest with yourself if you find yourself here. You might even be rewarding yourself for your progress so far. Have you been giving less than 100% lately if so re-focus and double down.

The next theory is that a plateau is reached when the body’s neurochemical counter-regulatory systems counterbalance the weight loss (Bray, 2003). In other words your body has reached a new set point that includes your metabolism slowing down to compensate for your new lower weight. There is mixed evidence to suggest that your metabolism slows down when you lose weight. However now that there is less of you your body to maintain you do require fewer calories a day even if pound for calorie you’re still burning at the same rate. There is emerging evidence that people who reach a certain weight through significant weight loss require fewer calories a day to maintain that weight than those who are the same weight and never lost any to get there. That does give some credence to the idea that your metabolism does slow down due to weight loss but that’s it’s own separate topic which I’ll be tackling in the next month or so. This theory could mean that this readjustment period is temporary or permanent but other studies argue that this is not the case.

The next theory is the muscle weighs more than fat argument. The idea here is that you are losing fat but at the same time gaining muscle and therefore the scale isn’t moving. Under this theory even though the number on the scale isn’t moving right now you’re still making progress because not only are you shrinking you’re also getting fitter and losing fat. Those muscles you’re building are burning more energy than your old fat was so it’s only a matter of time until your body catches up and that number starts moving again. In fact this theory says that all that muscle you’re gaining will even boost your metabolism in the long run. If you’re killing it in the gym this could be true especially if you’re a lifter. But some plateaus go on longer than this alone can explain and that catch up seems a long time coming. But if you’re not an exerciser or you run, walk or cycle the same distance at the same pace each time this isn’t your specific explanation. This is one of the reasons it’s a good idea to track your body measurements as well as your weight.

Not really a big deal at first

Since you’re a normal human no one is giving you bags of money for hitting a certain weight on a given day. There’s nothing to lose (pun intended) by freaking out or giving up because your scale is seemingly stuck for a couple of weeks or more. This is one of the reasons taking measurements each week of your chest, waist, hips, legs and arms is a great idea. You may very well be shrinking even though the scale isn’t moving. Taking measurements from the start is a great way to stay motivated especially when a plateau hits. For most people they will see their measurements change as their weight seems stuck and that can be motivation enough to see it through. The goal is not only to lose weight but to keep it off by adopting a sustainable lifestyle for the long term and that’s why we want to slow down further charges if it can be avoided. It you cut your calories or increase your exercise too often, when its not necessary you’ll get to unsustainable pretty darn fast. If not you’ll soon be dealing with a short term solution to a long term problem. Letting some time pass at a weight you don’t love is no big deal in the long run. In the meantime celebrate your success so far.

When to make changes

I don’t think you really need to take any steps until at least 6 weeks have passed no matter what. If you’re getting pretty close to your goal weight, within 20 pounds that number goes to at least 8 weeks. In either case for the vast majority of people the situation will have resolved itself within that amount of time and you’ll be losing again. Plateaus are a whole lot more than the scale not going down for a couple of weeks and we expect that as you get closer to you goal weight that movement will slow down. That might mean you’re only going to lose a pound every two or three weeks now. Many people who have a plateau do experience a few weeks after where the body seems to ‘catch up’ once the numbers start dropping again.

If you do find yourself well and truly stuck well all hope is not lost. You definitely can get back on track with your weight loss goals. The fact that it’s a decently well studied phenomenon means that you’re not alone. This happens to a lot of people. But you will have to make some further changes. The goal here to make these changes only as small as they need to be and not overshoot the goal. If that amount of time has passed and you’re not seeing changes you have a couple of options or both.

Lower your intake

If a few weeks have passed as we discussed above one option to break through your plateau is to eat a tad less. Cut your calories by 100 per day and only adjust that again by another 100 after 4 weeks on your new intake level. That 100 calorie cut adds up to roughly a pound a month add to that the common catching effects and you’ll be back on track in no time. If you get to the point where you have cut an additional 400 calories a day then stop cutting back for at least a coupe of months. If you cut an additional 400 calories a day for two months and the scale isn’t moving again you’ve got another problem. Chances are you’re not keeping close enough track of your intake. Start to rigorously track calories in the moment again and carefully measuring the weight and quantity of food. Out habits tend to get lax over time. If you’re still stuck it’s best to engage the services of a professional like doctor or dietitian.

Move more

The other option is to move more on average per day. For the most part this is the option I favor especially if you are not currently exercising. One of the things we know about people who lose weight and keep it off is that they tend to be pretty serious exercisers. Not necessarily strenuous exercisers but rather they spend a serious amount of time on it. On average long term successful dieters move 5 hours a week on average. Since you not only want to lose weight but also keep it off it’s a very good idea to aim to eventually get to this average too. There really isn’t a reason to ever go above this level. Maybe it’s time to up your intensity. No you don’t have to become a runner and most of those people simply use walking for exercise. If you’re having a hard time finding something you love just keep searching there are hundreds and hundreds of options. You’ll find yours eventually.

Think long term

Losing weight is not something anyone sets out to do as just a temporary thing. However that is what happens to lots of people. Studies show that getting support for a long time, like 4 years means that those people are likely never to return to their pre-diet weight (Headland et. al, 2016). Those people got ongoing support from nutritionists and therapists for 48 whole months were the ones that didn’t gain it all back. You can also reach out for that kind of help or just set yourself up with the mindset that this is going to be a years long commitment. Stick with your program if it’s been working and realize that if the scale doesn’t move even for a few months that doesn’t really matter. If you hit a plateau and then get through it think a bit about how it made you feel and what worked to get you through it. You might very well hit another one down the road. Make sure you take all you can from the first experience so that the second time around is easier.

Have you ever hit a weight loss plateau? How long did it take to get that scale moving again? What if anything did you do differently?

Some other posts you might find helpful

Are you on a diet that’s doomed to fail (again)

How to finally lose the weight, no BS!

The science of diets

The myth of 1200 calories

Science of ketosis

Can little changes lead to big pounds lost?

Why running isn’t a good sport for losing weight (sort of)

Read what I read

Bray, 2003. Low-Carbohydrate Diets and Realities of Weight Loss. Journal of American Medicine.

Chaput et. al, 2007. Psychobiological effects observed in obese men experiencing body weight loss plateau. Depression and Anxiety. 

Headland et. al, 2016. Weight-Loss Outcomes: A Systematic Review and Meta-

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