Why You're Not Losing Weight

While inspirational, it can also be discouraging to scroll through other dieters' stunning transformations... especially if your own attempts at weight loss and body change composition have left you with less to show for it.  

For explanations on why you may be hitting those pesky weight loss plateaus - and and how to avoid them - read on! But first, check out these great resources to help push you past them, designed for you by our PhDs, Registered Dietitians and Doctors to ensure steady, lasting weight loss: 

  1. The RP Diet App The best of our expertise coupled with machine learning for a simple, interactive, mobile experience (now with bar code scanning for a fully personalized diet)!

  2. The RP Simple Diet Template This 3-meals-a-day (+ "anything goes" snack!) program offers a variety of no-fuss, delicious options from each food group!

  3. The RP eCookbook bundle 5 of our best cookbooks full of recipes to help keep your fat loss diet meals fresh!

  4. The RP Diet 2.0 The 2nd edition of our foundational guide to fueling your body for optimal physique and performance (where you'll find deep dives into the principles below)! 

Why You're Not Losing Weight

*Note: As a caveat, we’ll often use the expression “eating less”. However, we use this for simplicity -- it could also be replaced by “moving more”. What matters is that your energy expenditure is greater than your energy requirements.

1. Your Fat Loss Is Invisible

Weight is a proxy for fat loss, but it's not perfect. It shifts a lot and water weight may mask fat loss. The best way to avoid this masking is making sure you're weighing yourself with minimal clothing, before eating or drinking anything, and after going to the bathroom.

Most importantly, you need to ignore individual weigh-ins, what matters are weekly averages and trends.

Your bodyweight fluctuates daily, mostly from the water your body is holding. On top of normal daily water fluctuations, other factors influence it even further -- like training (if you're over-reaching or deloading, for example), stress, and sleep.

The more you weigh yourself, the more accurate this average is. Some of our clients weigh themselves every day -- which makes for a very accurate reading when averaged out. For some, this may be stressful, so having fewer weigh-ins is okay. About 3-4 times per week would be good enough, and 2 would be the bare minimum. You want to compare each weekly average against the next. If you're losing slowly on purpose (if you diet less aggressively), a 2-week average may be beneficial or necessary, but in most cases, a single week is enough.

For women, there is the additional problem of the menstrual cycle, which is composed of 4 phases: early follicular, late follicular, early luteal and late luteal. Bodyweight is at its lowest on the first one, then increases for the second, decreases for the third, and then increases again for the forth. As you can guess, this makes the reading of your weigh problematic. From experience, this is not a huge concern -- as long as you're aware that the menstrual cycle impacts your weight. So if your weight during menstruation is not what you expect, you know it might just be water retention and you can simply ignore that week's readings. For some women, the fluctuations between phases might be quite drastic, and the previous method may not be sufficient. In that case, I'd recommend comparing the averages between phases. For example, you can compare the weekly weigh-ins of the week following menstruation, and compare it to the same week of the previous cycle.

In the end, the way you approach this issue depends on what you're willing to risk and what your goals are. If you're not losing weight, it's always possible that indeed you're not losing fat at all. You may have reasons to infer that you're losing weight but it's being masked -- there is no way to know for sure. If you want to make sure you're losing weight and don't want to waste time, then you can just assume you're not losing weight and decrease your intake. The consequence of this is to perhaps go more aggressively than what you needed, in case your original assumption was wrong.

On the other hand, if you want to be more conservative and make sure your intake is as high as possible while losing weight, you might want to wait a bit longer to see if any weight loss happens. The consequence of this is that you're potentially wasting time and not actually losing any weight. It's a trade-off with no right answer.

We illustrate this trade-off in the chart below. The green is a positive outcome, and the red a negative one. Hypocaloric meaning a caloric deficit - eating less, and isocaloric meaning at caloric balance - eating exactly the amount you need to maintain your bodyweight, and not losing or gaining weight. The tricky part is that you can’t know for sure which scenario you’re in, hypocaloric or isocaloric, and thus the trade-off.

2. You're Tracking Incorrectly

This is super common with people who are new to tracking their food intake. This is especially troublesome because people aren't doing it on purpose nor do they know they're doing it. Everyone disputes this, but a lot of times, in the end, they realize they were doing something wrong. I've dieted countless times for about 5 years and we at RP know almost everything about dieting in and out, and this still happens to us from time to time -- especially when we're deep into dieting. Folks will misread a label, forget to log a snack, assume certain macros that ended up incorrect, etc...

The first response for most people is to immediately think that's not the case with them. Everyone thinks they're tracking correctly. Of course, you might indeed be tracking correctly, but if you weren't, you wouldn't know. So be skeptical of your own judgment -- even if it’s counter-intuitive.

The most classical example to illustrate how misleading food portions can be is peanut butter.

(Credit: healthbeet.org - Amy Roskelley) 

The one on the left is an actual serving size of peanut butter - 100 calories. On the right, it’s a double serving - 200 calories. Just kidding. The one on the left is already a double serving - 200 calories, and the one on the right is a whopping 350% of a normal serving -- reaching 350 calories, higher than a McDonald’s cheeseburger. You may have guessed that the right picture was quite a lot, but very few would have correctly guessed by how much.

Misreporting is incredibly common. In one study (Champagne, 2012), subjects under-reported their intake by an average of 429 calories. You may imagine, some experience with tracking and nutrition helps. Unfortunately, it doesn’t help that much. The study also had a group of dieticians, and while they were more accurate, they still under-reported 223 calories per day -- almost a regular size Snickers bar!

(EE being their energy expenditure and EI their reported food intake.)

You may also be misled in your caloric intake if you eat out often. Some restaurant foods and some packaged processed foods can average 8-18% more calories than what they claim, and some items can have over 200% more calories (Urban, 2010). As your calories get lower and lower, it might be best to avoid until you're on maintenance again. 

Be super careful and mindful of how you're following the plan and you might discover some slip-ups which are very common. While we present several possibilities of why you’re not losing weight in this article, from experience, this is by a wide margin the most common.

3. You're Not Being Compliant

To put it bluntly, a lot of people just don't stick to the plan. Lack of compliance usually comes in two forms: unaccounted snacks or off-plan eating.

The first one is problematic because it's hard to notice. Most people think it's either not a big deal, or they simply forget. But small snacks can definitely add up and cancel your deficit.

Trying to avoid snacks altogether is not a bad idea when dieting. If you prefer not to, then make sure you know exactly the calories you're eating beforehand, and track it before you eat it, so there isn't a chance of you forgetting to log it later. 

The second one is off-plan eating, in a more general sense. Some people may simply succumb to an ice-cream in the freezer or go out and eat a whole pizza by themselves. When talking about eating off-plan, it's always worth mentioning binging. Going off-plan is not abnormal. People aren't robots and everyone messes up from time to time, but having binging episodes is concerning. If you binge, you may want to check the diagnostic criteria of binge eating disorder, and if it feels familiar, you should talk to your doctor.

The most common form of going off-plan is overeating on the weekends. A lot of people can stick to their plan during the work-week while they're busy with work and don't have much free time, but once the weekend comes, their eating plans go right out the window. This can easily mess up your average caloric intake. If your maintenance is 2000 calories and you’re eating 1500 calories from Monday to Friday, but on Saturday and Sunday you consume 3000 calories (which is not as high as you think... for reference, a tub of Ben & Jerry's is 1100+. Sorry Ben & Jerry, but that means something like Enlightened is going to be a game changer for many!), then your average is 1930 calories -- leading to minimal or nonexistent weight loss.

Again, people aren’t perfect, and sticking to any habit (diet or not) is difficult. The point is that it's unhelpful to try to lower your caloric intake when you aren't eating, on average, that theoretical intake in the first place. You would be much better off working on your consistency to the diet.

4. You Need A Lower Food Intake

Assuming you're being compliant and not making any mistakes tracking, then there is another possible cause: you're eating too much, even though you're following the plan correctly. Your plan estimates the calories you need for weight loss, but at the end of the day, it's an assumption -- and that can be wrong. If you're doing everything perfectly but still not losing weight, then you're not in a caloric deficit.

A lot of people think this is impossible because their calories are low already. They’re likely wrong and committing the mistakes outlined above, but if indeed they're eating that many calories, then it's still too much and is preventing their weight loss. We know this sucks, especially for small females which may have to go pretty low in calories to lose weight, but it's just how it is. There are a few things that you should understand when doubting that you don’t need to eat fewer calories.

  1. Having a lower body weight requires fewer calories
    The leaner you get, the lower you have to go in calories. Food is the energy source your body uses, and it uses it for its daily functions, and the heavier you are, the greater the cost of any given activity. If you get leaner, you weigh less and thus require less energy. It sucks, but there is no way around besides trying to compensate with more activity (which is generally not very feasible).

  2. BMR slowdown
    This is independent of the previous point. Your energy requirements go down besides what is predicted from the change in body weight, body composition, or activity. It changes the basal metabolic rate itself (the amount of energy expended while at complete rest). But this effect is small, and limited. It adapts once you’re in a deficit, but then remains unchanged (Rosenbaum & Leibel, 2016)
  3. Changes in non-exercise activity
    Quoting Levine (2002): "Non-exercise activity thermogenesis (NEAT) is the energy expended for everything we do that is not sleeping, eating, or sports-like exercise. It ranges from the energy expended walking to work, typing, performing yard work, undertaking agricultural tasks and fidgeting. Even trivial physical activities increase metabolic rate substantially and it is the cumulative impact of a multitude of exothermic actions that culminate in an individual's daily NEAT."

    This is important because it’s very often the cause of people’s perception of someone having a high or low metabolism. It's not like someone with a high metabolism just burns a lot more calories doing nothing, that person moves more (burning calories), even if it’s not noticeable.

    The effect on NEAT can be quite significant. In Leibel (1995), they had subjects under an 800 calorie deficit. The decrease in NEAT accounted for a third of the decrease in TDEE (maintenance calories) in lean subjects, and up to half in obese subjects. That's 250-400 calories.

    While we said that the BMR slowdown is finite, this doesn’t seem to be the case for NEAT.  The greater the deficit and weight loss, the greater the reduction in NEAT (Rosenbaum & Leibel, 2016). This emphasizes the importance of non-exercise activity, which will impact your weight loss without you realizing it.

  4. There is a lot of individual variance.
    The variance in BMR is rather small, about 10-15% for people who are the same size (Rosenbaum, 2008), but NEAT can impact it to a large degree. Here's a graph from Black et al. (1996), presented by James Krieger, on the impact of NEAT into energy expenditure.

    The significance of all of this is that people have the tendency to think outside of calories. They might think it’s specific foods they’re eating, that there is something wrong with their hormones, etc... But unfortunately, that's misguided. We know for a fact that if you're in a caloric deficit, you'll lose weight. Countless studies have shown that when people are monitored 24/7 in a laboratory if their intake is low enough, they'll lose weight. So if all the previous points are covered, and really often they’re not, the bottom line is that, to lose weight, we just have to eat less.

5. Medical Conditions

Lastly, there are medical conditions that make losing weight difficult. The 2 most common are hypothyroidism, which make you not produce thyroid hormones which regulate metabolism, and polycystic ovary syndrome (also known as PCOS) which is caused by elevated androgens.

Medications can also interfere with weight loss, including antipsychotics, antiepileptics, antidepressants, birth control, and many more.

If you think you may have any medical condition that is interfering with your weight loss, talk to your doctor. Most conditions can be successfully treated or mitigated with lifestyle interventions or medications. And if you’re taking a drug that influences it, you could potentially switch to another medication that doesn’t have an effect on body weight. All matters regarding medications should consult with their Doctor or their Registered Dietitian. 

However, it’s worth pointing out a couple of things:

  1. People have a tendency to think the lack of their weight loss success is because of a medical condition, but it’s very often not the case. In one study, when researchers took obese people claiming to be eating less than 1200 calories and not losing weight, their actual intake turned out to be double of what they claimed (Lichtman et. at, 1992). Mistracking is a lot more likely, and should be your first assumption.

  2. Even medical conditions and medications don’t change the role of calories. They either increase appetite and/or lower the metabolic rate. Losing weight is still possible, just more difficult and may require some tweaking that healthy people don’t have to worry about. You should absolutely try to improve it, but it’s important to remember that even in the extreme and rare case that you’re not losing weight, it’s still about calories, and all the above still applies.

If you suffer from a medical condition, you are not able to use our app.
You can however, work with one of our registered dietician 1:1 coaches!

Not losing weight can be frustrating when you’re putting so much time and effort into it. It’s important to understand the cause of the plateau, so that you can address it directly. Otherwise, you will seek and implement fixes that don’t help you reach your goals. Stay calm, analyze the situation, and implement the needed change(s) that will be sure to result in your desired weight change.

Here is a chart summarizing the article. While this isn't set in stone, a pretty good guideline is taking into account the scenario at the top, and move down as needed. 


Champagne CM, Bray GA, Kurtz AA, Monteiro JB, Tucker E, Volaufova J, Delany JP. Energy intake and energy expenditure: a controlled study comparing dietitians and non-dietitians. J Am Diet Assoc. 2002 Oct;102(10):1428-32. PubMed PMID:

Urban LE, Dallal GE, Robinson LM, Ausman LM, Saltzman E, Roberts SB. The accuracy of stated energy contents of reduced-energy, commercially prepared foods. J Am Diet Assoc. 2010 Jan;110(1):116-23.

Rosenbaum M, Leibel RL. Models of energy homeostasis in response to maintenance of reduced body weight. Obesity (Silver Spring). 2016 Aug;24(8):1620-9.

Rosenbaum M, Leibel RL. Models of energy homeostasis in response to maintenance of reduced body weight. Obesity (Silver Spring). 2016 Aug;24(8):1620-9. doi: 10.1002/oby.21559.

Leibel RL, Rosenbaum M, Hirsch J. Changes in energy expenditure resulting from altered body weight. N Engl J Med. 1995 Mar 9;332(10):621-8. Erratum in: N Engl J Med 1995 Aug 10;333(6):399.

Levine JA. Non-exercise activity thermogenesis (NEAT). Best Pract Res Clin Endocrinol Metab. 2002 Dec;16(4):679-702.

Rosenbaum M, Hirsch J, Gallagher DA, Leibel RL. Long-term persistence of adaptive thermogenesis in subjects who have maintained a reduced body weight. Am J Clin Nutr. 2008 Oct;88(4):906-12.

Black AE, Coward WA, Cole TJ, Prentice AM. Human energy expenditure in affluent societies: an analysis of 574 doubly-labelled water measurements. Eur J Clin Nutr. 1996 Feb;50(2):72-92.

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