If you’re in a calorie deficit, you will (eventually) lose weight.
This is a fact.
You are not special and your body is not exempt from the laws of thermodynamics.
Now we’ve got that slightly passive-aggressive intro out of the way, let’s look at a few explanations as to why you might be in a calorie deficit (or so you think) but not losing weight.
The Possible Problems…
1. The Deficit Doesn’t Exist
This is the most common scenario and will be the situation for 99% of people that think they’re in a calorie deficit.
I’ve had people tell me in the past that they’re in a 1,000 calorie deficit and not losing weight. This simply isn’t possible – if you’re in a 1,000 calorie deficit per day, you WILL lose weight. No question about it. In fact, at that rate, you’d lose about 1lb every 3.5 days.
Your body will tell you if you’re in a deficit, not the other way around; i.e. if the scale is going down consistently, it means you’re in a calorie deficit, if it’s not, then you’re not.
It’s that simple.
If you start eating fewer calories, your metabolism may adjust slightly to compensate, but not to the degree that it would actually stop you losing weight.
If you’re not losing weight, you either need to drop your average daily calorie intake, increase your activity, or both until you start losing weight – as soon as that starts happening you KNOW you’re in a calorie deficit.
So why might you don’t actually be in a calorie deficit, even though you think you are?
2. You’re Not Tracking Your Calories Accurately
If you’re so damned sure that you’re in a deficit, your tracking had better be on point. There are many mistakes people making with tracking; including
- Not tracking everything – if you’re going to track, track EVERYTHING. That includes coffees (yes your Starbucks triple twatachino does have calories in – and lots of them), mayonnaise, that cheeky Fanta; all of it.
- Tracking cooked weight instead of raw weight – 100g of raw rice is very different from 100g of cooked rice – you can see the differences below. Don’t make this mistake
- Not tracking at weekends – contrary to what Karen in accounts says, weekend calories do count – your body doesn’t acknowledge that you deserve a ‘treat, so make sure you’re tracking every day.
3. You’re Overestimating How Many Calories You Burn Each Day
TDEE stands for total daily energy expenditure, i.e. the total amount of calories you burn on average per day – you can work it out here.
The problem is, many people take their TDEE estimation for granted – just because the calculator says you burn 2000 calories per day doesn’t mean you do.
How do you know how many calories you burn each day? You don’t.
Pick a calorie amount that you’ll stick to each day -if you lose weight, you’ll know that this is less than your TDEE, if you maintain your weight, you’ll know that calorie amount is roughly your TDEE, if you gain weight, you’ll know that that calorie amount is more than your TDEE.
If you want help calculating how many calories you burn each day (so you can get an idea of how many you be eating), pop your email address in below and I’ll send you my free e-book that tells you how to do exactly that.
The other thing to be aware of is that if you lose a lot of weight, your TDEE will change because as you get lighter, your metabolism will come down so you’ll need to reassess your calorie intake at regular intervals, which leads me on to the next point….
4. Metabolic Rate Has Reduced
Contrary to what most people believe, as you lose weight your metabolic rate will come down.
Yes, the lighter you are, the lower your metabolism will be. This is because your bodt doesn’t need to work as hard (and use as many calories) to move your body mass around, simply because there’s less of it.
This means that, if you weigh 80kg, eating 2500 calories per day may be enough to lose weight, but when you’re down to 70kg, you may well maintain your weight eating 2500 calories, so you’ll need to reduce the number of calories you eat to carry on losing weight.
There are many factors that make up your overall metabolsim however, and the one that will reduce as your weight comes down is your BMR (Basal Metabolic Rate).
This makes up the largest percentage of your overall metabolism, but you can get around it by doing more formal exercise and upping your NEAT (non-activity thermogenesis e.g. fidgeting, general movement).
So, for example, if you’ve gone from 80kg to 70kg and you now need to eat 2000 calories per day to lose weight (rather than 2500), you could carry on eating 2500, but negate the extra 500 with 500 calories worth of exercise.
In short, the more weight you lose, the fewer calories you’ll need to eat. to maintain the same rate of weight loss.
It’s impossible to ‘pre-empt’ what your metabolism will be at any given point. This is why it’s so important to track and monitor your calories, steps and weight on a daily basis so you can quickly spot weight loss plateaus and act accordingly. If you don’t know how to do this, a weight loss coach can help.
5. You’re Eating Less Protein
This is more of a sub-point to the one above, but protein has a high ‘TEF’. TEF is the ‘Thermic Effect of Food, i.e. the number of calories your body uses digesting that food. Protein is more difficult for the body to breakdown than carbs or fat, so you’ll burn more calories digesting protein-rich foods than you will with carb or fat-based foods.
In fact, this study found that the TEF of protein can be 20%-30%, i.e. if you eat 100 calories of protein, 20-30 of those calories will be burned just digesting the protein!
This means, the higher the ratio of protein in your diet, the more calories you’ll burn doing nothing. Conversely, if you start eating less protein (but the same amount of overall calories), your TEF will reduce, which could be enough for your bodyweight to plateau or even increase.
6. You Could Be Gaining Muscle
losing fat and gaining muscle at the same time, also called body recomposition is quite hard to achieve, and quite a rare scenario.
It is definitely possible to build muscle and lose fat in a calorie deficit, which could mean that your weight remains static or even goes up slightly.
Unfortunately, measuring your body fat percentage is a very time-consuming and expensive task. A DEXA scan is the most accurate way to get this data, but you’re looking at £150 a pop, and even this isn’t totally accurate.
What is means is that your probably won’t be able to objectively measure if you actually building muscle in a deficit, but you can eyeball it in the mirror – and if you’re looking better, who cares what the numbers on the scale say?
It is normally complete beginners that can build muscle in a deficit, so it may be common for people who start lifting at the same time as they start their diet to experience slower or even no *weight loss* – in reality what’s happening is they’re losing some fat, and building some muscle.
Both of those things add up to a better physique.
7. You’re Weighing At Different Times Each Day
Weighing yourself everyday is a really good idea, regardless of whether your goal is weight loss, gain, or maintenance.
You should however do this at the same time everyday.
This is because eating and drinking throughout the day will make you heavier simply because the liquid and food is in your gut.
If you weighed yourself, drank a litre of water, then weighed yourself again, you’d be roughly 1kg heavier (1 litre = 1Kg).
This means that if you weighed yourself on Monday morning, lost some fat (it would only be a tiny amount over the course of a day – but this is for demonstrative purposes), then weighed yourself again on Tuesday evening, you’d likely be quite a bit heavier than you were despite losing some fat.
The best time to weigh yourself is first thing in the morning after you’ve been to the toilet but before you eat or drink anything, ideally without clothes on. This will give you the ‘truest’ reading of your weight. More important however is weighing yourself consistently so you can accurately judge your progress; I recommend once a day.
8. You’re Retaining Water
High stress levels can have both an indirect and direct efect on your weight.
Indirectly, stress can lead to overeating as a coping mechanism. This study looked at the relationship between perceived stress levels and body weight in two groups. One group was subjected to intervention methods which included breathing and relaxation techniques. The intervention group reduced their BMI by twice as much on average compared the control group.
The study suggests….
“The reduction in perceived stress levels in the intervention group, could have led to the adoption of healthier dietary habits and subsequent weight loss”Xenaki et al, 2018
Stress management could therefore indirectly lead to more wieght loss since there is less temptation to overeat.
From a direct point of view, increased water retention can happen if you’re stressed, or haven’t slept well (which can in itself create stress). Water retention can of course increase bodyweight and while it may not be fat, it can give you a bloated look.
9. You’re Eating Back Exercise Calories
If you’re using My Fitness Pal to track your calorie intake, that’s awesome, well done (that wasn’t meant to sound sarcastic).
There are a few things that lots of people get very wrong with My Fitness Pal however. One of these is tracking ‘cooked’ rather than ‘raw’ or ‘dry’ weights of food (e.g. meat, pasta, rice), another common one is ‘eating back’ exercise calories.
My Fitness Pal will show you something like this;
See the ‘remaining’ number? Ignore it.
My Fitness Pal is saying that based on your calorie goal, and the calories you’ve burned working out, you can eat another 418 calories and still hit your goal.
The problem is, the estimates of calories burned for a workout could be totally off. The goal could be totally wrong as well (i.e. it might only be low enough to allow you to maintain your weight rather than actually lose weight), if the goal is too high for weight loss, any calories you eat back could tip you into a calorie surplus and actually result in weight gain!
Definitely use My Fitness Pal to TRACK calories, but you can ignore the calories ‘remaining’ – listen to your weight loss coach when it comes to target calories and when your calorie intake or activity should change, based on your goal.
IGNORE what your fitness tracker says about the exercise calories you’ve burned. You might think you need to reward yourself after running 10 miles but don’t. These calories should already be factored into your daily targets. If you’re syncing your tracker with My Fitness Pal; stop.
10. Your Mensural Cycle
For women, the menstrual cycle can also play a part in weight fluctuations. Again this is usually down to water retention, so take this into account if your weight increases on or around your period.
11. You’re Not Sleeping Enough
There is a strong correlation between lack of sleep and higher bodyweights. It is thought this is because lack of sleep stimulates ghrelin, the hormone that stimulates hunger. This study found that less sleep meant greater ghrelin production
Another study found that calorie intake was 14% higher in a group that got 4.5 hours sleep compared to a group that got 8.5 hours sleep.
Of course, getting less sleep doesn’t automatically result in weight gain on it’s own, but it could mean that sticking to a calorie goal is more difficult because the drive to eat is greater.
12. You’re Eating ‘Clean’ or Doing Keto
‘Clean Eating’ is a diet methodology that prioritises whole, unprocessed foods and maximising nutrient density. From an overall health point of view, this is sensible, but it may not go hand-in-hand with weight loss. A ‘clean’ diet is one that includes lots of fresh veggies, fewer carbs and more high-fat foods like salmon, nuts, oils, eggs and avocados; these are all fantastic foods to include in your diet BUT they are all high in calories (gram for gram), this means if you purely focus on nutrient density, you might think you’re eating healthy, but still gain weight because your calories are too high. Regardless of WHAT you eat, calories are still important if you want to lose weight. So track them!
There are very few reasons why weight may not decrease despite being in a calorie deficit, and those reasons are quite rare – so if you think you’re in a calorie deficit, check all of the above first.
And yes, for most people, a 1,000 calorie per day diet WILL result in weight loss, even if you’re inactive.
What if You’re Gaining Weight in a Calorie Deficit?
If you are gaining weight in the long term, i.e over a period of several weeks or months despite being in a calorie deficit, then you are 100% categorically NOT in a calorie deficit. That’s a fact. Instead, this means that you’re in a calorie surplus, i.e. eating more calories than you use on average each day.
However, if you gain weight in the short term, i.e. over a couple of days or even a whole week, this is likely to be natural fluctuations, which could be anything from;
- Food still being in the gut
- Water being in the gut
- Water retention at a cellular level from stress
- A recent high intake of carbs
It is important to remember that weight loss is NOT linear. This means that even if you are in a calorie deficit and losing weight in the long term (weeks and months) you could still gain weight in the short term (day-to-day).
Below are real weight loss results from one of my clients. The trend line (the straight, faint line) shows the overall long-term trend, but the thicker line shows the actual weight on a day-to-day basis – look how much it moves around!
So, gaining weight during a period when you’re in a calorie deficit is totally possible and normal – don’t worry about it!
As mentioned, If you’re not losing weight, then you’re not in a deficit.
In order to test how many calories is enough to put you in a deficit, you need to measure and track.
Measure your calorie intake, steps, and weight on a daily basis. If your weight hasn’t decreased after 10 days, reduce the calorie intake, monitor for another 10 days. Keep repeating the process until your weight starts coming down – then you’ll know for a fact you’re in a deficit.
- Find Your Maintenance Calories Use a tool like the TDEE calculator to help you do this. But remember, the number it gives you is an ESTIMATE, so don’t treat it as gospel truth
2. Create a Calorie Target Whatever number the TDEE tool gives you, take 10% off. So if the TDEE calculator says you burn 2000 calories in a day, take 200 calories off, leaving you with a target of 1,800 daily calories
3. Track Stick to that calorie amount daily for 3 weeks. Weigh yourself every morning and write it down or record it. Track your calories ACCURATELY in My Fitness Pal. Make sure you do about the same amount of exercise each week.
4. React If after 3 weeks, your weight hasn’t started coming down, take another 10% off your daily calorie target. Repeat until weight loss starts to happen.
When your weight goes down – you know you’re in a calorie deficit!
Other Calorie Deficit FAQs
Is it Possible to have a Calorie Deficit and Not Lose Weight?
No. At least not over a long period of time. Regardless of whether you’re in a deficit or a surplus you weight will fluctuate on a daily basis, but if you’re genuinely in a deficit over a long enough period of time you WILL lose weight, gauranteed.
Why Am I Eating Less and Not Losing Weight?
Just because you’re eating less than you were before doesn’t mean you’ll definitely lose weight. Calorie balance is about calories in AND calories out. If you eat less, but you do less activity as well, your weight could stay the same or even increase.
Why Am I gaining Weight While Dieting and Exercising?
if you’re training with weights, you could be gaining muscle. If your level of bodyfat stays the same, this does mean that you’ll gain weight, BUT you’ll end up looking better because the fat will be spread over a larger surface area.
How Many Calories Should you Eat to Lose 5 Pounds (roughly 2kg) a Week?
Losing that much weight on a weekly basis is unsustainable. Most people should look to lose around 1-2lbs per week.
How Do I Know If I’m In a Calorie Deficit?
If over a 2 week period, you’ve lost a significant amount of weight (2lbs and upwards) you can be pretty sure you’re in a calorie deficit.
Should Women Eat Any Less Than men to Lose Weight?
When it comes to weight loss, women’s bodies don’t work any different, but women will GENERALLY need to diet on fewer calories than men, because they weigh less which means they have slower metabolisms.
Is 800 Calories a Day Safe?
It’s safe, but for most people it’s going to be unsustainable. You should look to diet on as high a calorie amount as possible. Dieting on super low calories will only lead to a binge and restrict cycle, and eventually giving up and going back to the way you were eating before.
Can Eating Too Little Make You Gain Weight?
Impact of a stress management program on weight loss, mental health and lifestyle in adults with obesity: a randomized controlled trial: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6296480/
Diet induced thermogenesis: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC524030/
Insufficient sleep undermines dietary efforts to reduce adiposity: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2951287/
Sleep and obesity: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3632337/#R43
Joe is an online weight loss coach and qualified personal trainer of 15 years who helps busy, professional men and women lose fat and build muscle.
Having a 9-5 desk-job, Joe understands the struggles of juggling a hectic life with trying to maintain a good physique.